XS1100 AUSTRALIA
XS1100 Topics => Modifications => Topic started by: Jaymo on May 27, 2019, 08:23:55 AM
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My bike is a 1981 XS1100H. It's the US "Venturer" touring model.
Long story short: Original BS34s had a broken float post on #4 carb. Replaced them with Keihin CVK36 from a 2005 ZRX1200. Had some issues with them from the start. Ended up with 3 of them flooding. Instead of throwing more money at them, I replaced them with brand new Mikuni RS36-D3K flat slide pumper carbs (yesterday). This allowed me to get rid of the air box which got full of water whenever it rained (still haven't figured that one out), and full of gasoline because of the carb flooding issues.
So, I've got K&N pod copies on them. The carbs were installed with no changes made to factory jetting. Main jets are 130s.
Since I'm currently still running the factory 4 into 2 exhaust and mufflers, I figure I'll probably need to install the 125 or 120 jets that also come in the box with the new carbs.
So far, the bike sounds a lot better than it has since I've owned it.
My problem is, when I snap the throttle open from idle, the engine bogs and dies.
If I ease into the throttle, I can snap the throttle open once the RPMs get above about 2000, and it roars like a homicidal wild beast.
However, the RPMs hang and drop slowly to idle once I release the throttle.
The pilot screws are 1/2 turn out.
Idle is a bit rough at 1000 RPM and better at 1050-1100 RPM.
I haven't taken it for a test ride, because I deem it unsafe in its current state.
I installed new NGK BP6ES plugs with the carb install, since the old ones were heavily petrol fouled.
The ignition coils are the green, 3 ohm Dyna coils with Dyna plug wires.
Vacuum advance connected or disconnected makes no difference.
When I tested my pickup wires and coil wires last year, they tested good.
I removed the TCI and checked for cracked solder joints and found none. I cleaned the terminal pins in the TCI and harness connectors with Deoxit.
I eliminated the OEM fuse box and went with blade fuses.
What say ye? Adjust the pilot screws richer?
Drop the needle clip one notch?
Swap the 130 mains for the 125 mains that come with the carbs? (after curing the idle/acceleration issues).
It's weird, because It definitely smells rich at higher RPMS and sometimes at idle, but dies upon whacking the throttle open.
Any advice greatly appreciated.
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G,day Jaymo
I'm no tuning expert but itd oes sound like its being over fuelled
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Hey Jaymo,
Check out the video Andy did on fitting these, see below. I have mine set the same as he did copying the fj1200 recommendations. Think it was the 130 mains but it’s in the video.
I believe the recommended setting for the fuel mixture screw is 1/8-1/4. I’m at 1/8 at the moment and it seems to run better.
Being the D3K model I believe you would have had to change throat measurement, ie reduce the distance between carb 2 and 3. Did you re balance the carbs after this?
Andy’s runs a treat and I don’t remember any lag on his when I rode it but I probably wasn’t game to reef the throttle on his as it has plenty more power than mine.
Mine is running bloody good but it still bogs down a little more than I would like in the lower revs.
Did you set the fuel pumper?
Did you rig up a vacuum advance.
I would also check for air leaks at the manifolds.
I plane on taking it in for a pro tune to get all the jetting and settings checked soon so I will endeavour to let you know results although I have the 1200 big bore kit and late model large valve head I don’t think it would be much difference.
https://youtu.be/5eUnbVAp8hI
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After adjusting the distance between the 2 & 3 carbs, I adjusted the balancing back to the factory, marked position.
I did adjust the accelerator pump, but may have to adjust it again. I'm tempted to have it come in later in the throttle opening.
I have not yet balanced them on the bike. I know I will have to, but want to get it closer to right before I do.
I may have to go ahead and balance them first.
First, I will adjust the mixture screws and see where that gets me.
I need to find my Colourtune.
Addendum: Jonesey :-) I think you hit the nail on the head. Funny thing is, I am a mechanic. Well, they call us breakdown technicians now. I'm the senior field breakdown technician at my dealership.
However, we are a forklift dealership, so I mostly work on LP, electric, and diesel forklifts. Rarely do I see a gasoline forklift.
So, my gasoline fuel system troubleshooting skills tend to be a bit rusty.
That and the fact that multi carburetion is a whole different kettle of fish.
That's one of the reasons I work on my own bikes and mowers, chainsaws, etc. It's to try to knock the rust off of those parts of my brain.
One of the pitfalls of using laptops, DVOMs, and handheld analyzers all the time is that you start to forget your pre-computerized fuel system troubleshooting skills.
Anyway, I still haven't found my Colourtune.
But, I DID pull the new spark plugs and found that they are BLACK.
My wife saw them and said "Oh, no."
I said, "Oh, yes. This gives me a direction in which to work. Now I know it's being overfueled/running too rich."
So, I'll start off running the pilot screws in and run them out 1/8 turn. After I clean the plugs, that is.
I may have to raise the needle clip one notch. I'm pretty sure I need to swap in the 120 or 125 jets.
I'll go one change at a time, so as not to muddy the water with too many changes at once.
I need to get one of fuel bottles that you hang up to allow balancing the carbs.
Or, I'll just install long enough fuel hoses to allow me to set the gas tank where the seat mounts while I balance the carbs.
The question is should I use vacuum gauges or should I use my Uni-Syn carb synchronizing tool?
I guess I could try the Uni-Syn and if it doesn't work, try to figure a way to stop my vacuum gauge needles from bouncing madly while balancing the carbs.
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Hey Jaymo,
Check out the video Andy did on fitting these, see below. I have mine set the same as he did copying the fj1200 recommendations. Think it was the 130 mains but it’s in the video.
I believe the recommended setting for the fuel mixture screw is 1/8-1/4. I’m at 1/8 at the moment and it seems to run better.
Being the D3K model I believe you would have had to change throat measurement, ie reduce the distance between carb 2 and 3. Did you re balance the carbs after this?
Andy’s runs a treat and I don’t remember any lag on his when I rode it but I probably wasn’t game to reef the throttle on his as it has plenty more power than mine.
Mine is running bloody good but it still bogs down a little more than I would like in the lower revs.
Did you set the fuel pumper?
Did you rig up a vacuum advance.
I would also check for air leaks at the manifolds.
I plane on taking it in for a pro tune to get all the jetting and settings checked soon so I will endeavour to let you know results although I have the 1200 big bore kit and late model large valve head I don’t think it would be much difference.
https://youtu.be/5eUnbVAp8hI
Basket Case was where I got the idea for the Mikuni flat slides. My favorite series on YouTube.
Andy is my hero.
I set the fuel pumper. Will recheck it after a few other things.
I replaced the manifolds and clamps when I replaced the carbs.
It runs the same, with or without the vacuum advance.
Since my new plugs are black, I now know that it's too rich.
Time to rectify that, one step at a time.
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mate - the only advice I can offer is -
make only one change at a time
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I put new manifolds on mine and that was the first time I had leak issues. Holding revs as you describe is a classic symptom.
It’s recommended not to use the gaskets they come with but use something equivalent to permatex ultra black sealant.
I found adjusting back to the factory marks on the carbs no longer had them balanced. I went over it several times and could not find a reason for it. I was a bit concerned I had done something wrong. Not sure if Andy had the same issue but I know he had a lot of trouble balancing his as you can see in the video. The balancing on these is very coarse. As in the slightest movement makes a big difference. I do believe however that being a little out is not as critical as it is on the cv’s.
First thing I would do is check the manifolds for leaks then pull the carbs off and do a bench sync. Then check for leaks again, then do a colour tune.
You may need to play with the jets at a later date but it should run very good as is.
If the plugs are blacking up in the driveway it would be the pilot jet that is too rich, changing the main jet won’t help much until you are out on the road.
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Agreed.
I'm going to adjust the pilot screws first and see what result I get.
Also, I used the gaskets that came with them and put Aviation Permatex on both sides of the gaskets.
I do know that once it's above about 2000 RPM, it revs to an indicated 10,000 RPM in less than the blink of an eye.
The engine sounds very mean with the Mikuni carbs. It sounds like an absolute beast now.
If I can just get these issues sorted.....
The fact that it gives symptoms of running both lean AND rich on the pilot circuit is what's so confusing for me.
Black plugs=rich.
RPM hanging=lean.
It shouldn't be both at one time.
I'm going to clean the plugs and let it run at idle for a few minutes and see what the plugs look like.
I may have to remove the gaskets and use sealer.
One reason I want to use the Colourtune is to see what color I get both at idle, and when the RPM hangs after throttle release.
Getting this thing running right has been like working on a Colt revolver. It's all a big balancing act.
BrettS what did you use for gauge rods/pins when you bench synced yours?
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Some stainless filler wire I had laying about. I would finally sync them flick the throttle a couple of times and it would be out again. They are a pain in the butt but I finally got a consistent result that was pretty close. With the vacuum balancer on I’m still out a little but I’m not sure I want to try and even attempt balancing with bike running.
I was getting damn good at balancing the cv’s but I think I’ll get the pro to do these running.
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I just checked out the aviation permatex, you can’t get any better than that lol. But I was told to leave the gasket out. Quick easy check to see if they are leaking though.
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I just checked out the aviation permatex, you can’t get any better than that lol. But I was told to leave the gasket out. Quick easy check to see if they are leaking though.
Spray WD40 on them while it's idling and watch/listen for changes in idle speed?
I should probably pull the pods off first, to make sure they're not blocking any of the ports on the carbs.
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Not sure there is anything that can be obstructed on these?
There are various compounds you can use. I like to use carb cleaner.
https://youtu.be/oKVHqCJN2LU
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After work today, I removed the pod filters and found that there are two air jets in the bell of each carb.
However, the way the filters are designed, there is nothing that can obstruct them.
It smells very rich at idle. I set my pilot screws to 1/8 turn out. No change.
I also noticed that I have some gas spitting out carbs 1 and 4 at idle. In fact, it washed some of the filter oil off of those two filters.
I also noticed that the stream of gas from the accelerator pump nozzles is hitting the slides.
So, I need to readjust the pump to stop from squirting fuel onto the slides.
But, what about the gas spitting out the carbs at idle?
These are brand new carbs, and I wouldn't think that the floats would be sticking, but I've been wrong before.
I guess I could whack the sides of the carbs with the plastic handle of a screwdriver and see if that improves things.
Could the restrictive OEM exhaust be causing this?
What else do I need to look for?
Thanks guys.
Also, I used carb cleaner to check for vacuum leaks. None found, so far.
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I’d go back to basics. If the carbs are reasonably balanced and not leaking I’d be looking elsewhere for the issue.
Have you got the correct tci for the ignition system. Is it 2h7 or 4RO. Does it have a mechanical advance. This model should have pre set timing, non adjustable.
The needle and seat on these carbs can stick open.
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I’d go back to basics. If the carbs are reasonably balanced and not leaking I’d be looking elsewhere for the issue.
Have you got the correct tci for the ignition system. Is it 2h7 or 4RO. Does it have a mechanical advance. This model should have pre set timing, non adjustable.
The needle and seat on these carbs can stick open.
The TCI is a 4R0.
Right now, I'm tempted to either cut off the factory mufflers or punch out the center baffles.
I'm planning on replacing them with straight through, glass packed mufflers. I have several options, but I think I'll go with some reverse cone mufflers with repackable baffles.
I installed the velocity stacks from my factory airbox onto my carbs. They seem to like that.
I just don't like the idea of riding without air filters. Maybe I'll make some that I can install my pods onto the ends of.
I can use the depth of insertion of the stacks into the pods to control air inlet flow restriction, if need be.
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That’s good news, looking in the pick up points area you should have the non mechanical advance type rotor and non adjustable timing plate.
I’m guessing from what you have said this motor hasn’t run correctly up to this point. It’s not like you had a good running engine and put these carbs on and then had problems. Hence I would be hesitant to start playing with the carbs before everything else is eliminated.
Sorry if I am going over what might have been covered in any other thread you had but I would
Check compression, check spark, check valve clearance check you have complete ignition system as above, check pick up coil wires again. Check your engine earth.
I believe from memory my fuel squirt also hits the slide. If it concerns you it will run reasonably well without even using it so you could disengage it for the initial tuning process.
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Also when checking valve clearance check your cams and cam chain is installed correctly. I’ve heard of these bikes running with a cam installed 180 degrees out or one tooth out and that could cause the fuel spitting back out of the carbs.
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Will do.
It ran great for about a month after I bought it.
Then, the PO's broken float post fix failed. That began the quest for better carbs.
Where does the engine earth connect to the engine and the frame?
I'll pull them and clean the terminals and termination points.
Another question. I have green Dyna coils.
The adapter brackets I made are made of aluminium angle.
I thought I saw/heard somewhere (Andy Gerding, perhaps?) that the brackets that bolt the coils to the frame need to be made from iron/steel, for the coils to work correctly. Is this true? If so, I need to rectify that.
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Earth the engine to the frame in a couple of places
Mine is both sides at rear - one shares the battery earth to frame
I'd be surprised if the aluminium or steel or copper brackets make a.difference as long as all connections are clean metal to metal
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As Bryan said, earth can be anywhere as long as it’s good doubling is even better.
I would disagree though and say that the connection from coils to frame must be a good conductor, not aluminium.
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https://answers.yahoo.com/question/index?qid=20080716201916AAjzfot
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I remembered this being an issue for someone else. Seems it’s not an electrical issue but a magnetic one.
https://youtu.be/JYVSyplZFMM
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I remembered this being an issue for someone else. Seems it’s not an electrical issue but a magnetic one.
https://youtu.be/JYVSyplZFMM
That's it. So, it WAS Andy's bike.
Let me scrounge some ferrous bits for mounting the coils.
Plus, I'll test my pickup coil wires again.
And, I'll check compression again.
And, I'll check valve clearances.
And, have a look at cam timing.
And, either punch out the stock baffles or just chop the damn mufflers off and replace them with something with much higher flow.
And, make some velocity stacks to move my pod filters back about 4".
And, maybe, buy and install a flame thrower exhaust kit, because flames.
And, replace the seat upholstery.
And replace the tires.
Good lord, it never ends.
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Jaymo, I understand your frustrations but please don’t chop up or wreck your STD exhaust, there worth a mint even in reasonable condition, a set of 4 into 1ns or 4 into 2’s out of Aus aren’t that expensive and seeing that your going down road of flat slides and pod’s, my opinion, and it’s probably only my opinion, 4 into 1 would be the go, just make sure they have equal length primary, or header pipes, or what ever you want to call them.
Unequal length primaries make it harder to tune.
I don’t really have anything else to offer, I think the others have covered pretty much every thing. You’ve stepped onto a steep learning curve by going away from std but that’s ok it’s your bike, and you will succeed, ONE step at a time,
Reupholstering the seat is probably a good start😎
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Jaymo, I understand your frustrations but please don’t chop up or wreck your STD exhaust, there worth a mint even in reasonable condition, a set of 4 into 1ns or 4 into 2’s out of Aus aren’t that expensive and seeing that your going down road of flat slides and pod’s, my opinion, and it’s probably only my opinion, 4 into 1 would be the go, just make sure they have equal length primary, or header pipes, or what ever you want to call them.
Unequal length primaries make it harder to tune.
I don’t really have anything else to offer, I think the others have covered pretty much every thing. You’ve stepped onto a steep learning curve by going away from std but that’s ok it’s your bike, and you will succeed, ONE step at a time,
Reupholstering the seat is probably a good start😎
I'd love to get a set of 4 into 2's that allow me to keep my center stand and not have to remove the exhaust, to change the oil filter.
I like the exhaust note of the 4 into 2 much more than the 4 into 1's.
To me, the 4 into 2's exhaust note sounds like "I'm going to chop your head off and skull-f**k it right up your *sshole." whereas the 4 into 1 exhaust note sounds like "Wheee, wheee."
I'm just not a fan of the crotch rocket/formula 1 car exhaust note.
No work will be done on the XS this weekend, due to severe thunderstorms and flash floods.
I. Hate. Rain.
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Finally got some time to mess with the bike, today.
I cleaned my ground points at the engine, regulator/rectifier, and frame.
I added a second engine ground wire.
I decided to test my pickup coil resistance again.
My pickup coil circuit resistances are 799 ohms and 807 ohms, measured at the connector that plugs into the TCI.
The ambient air temperature is 32 degrees Celsius.
Does this sound a bit high?
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"I'd love to get a set of 4 into 2's that allow me to keep my center stand and not have to remove the exhaust, to change the oil filter."
Jaymo
The MAC 4 into 2 will do that, the turn out ends look crap in my opinion but the straight cuts look ok. Apparently the do interfere with the oil cooler hoses but my bike doesnt have the oil cooler so cant confirm see MAC 4-2 below
(https://i.ibb.co/6ndg2Dg/zw93Zs.jpg) (https://ibb.co/6ndg2Dg)
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"I'd love to get a set of 4 into 2's that allow me to keep my center stand and not have to remove the exhaust, to change the oil filter."
Jaymo
The MAC 4 into 2 will do that, the turn out ends look crap in my opinion but the straight cuts look ok. Apparently the do interfere with the oil cooler hoses but my bike doesnt have the oil cooler so cant confirm see MAC 4-2 below
(https://i.ibb.co/6ndg2Dg/zw93Zs.jpg) (https://ibb.co/6ndg2Dg)
Nice. I have a pair of Cobra straight-through mufflers would look and sound great on that MAC 4-2.
I tested my pickup coil wires again, after the temperature dropped and the resistance went down a few ohms.
Not surprising. Anyway, I tested the wires from the TCI to the connector behind the fusebox panel, and from the connector behind the fusebox panel to the pickup coils.
No amount of wire wiggling made any difference in the resistance.
Actuating the vacuum advance made a difference of about 3 ohms, but so did placing a hex wrench near it, without touching the wires. I'm thinking it's just something to do with the magnetic field.
I put 4 gallons of fresh, no ethanol, gasoline in the tank and ran it.
It's definitely running better, but It's still not where I want it to be.
Then again, I'm not finished with it.
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So, what is the recommended tool for removing and installing the main jets in the RS36?
My Google-fu seems to be weak tonight.
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UPDATE!!!!
After work today, I made steel mounting brackets for the Dyna coils.
Upon lighting her up, I noticed an immediate improvement.
I didn't have to use choke to start.
It revs better.
It idles better.
It just runs better.
Now, I need to balance the carbs. Then, I can work on readjusting the accelerator pump stroke and timing.
Then, she'll get an Italian Tune Up. 8)
Then, I'll worry with plug chops, jetting, etc.
Frankly, I'm amazed at how much difference ignition coil mounting bracket material made.
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That mounting bracket material info is great to know - I have always used steel but am surprised that it makes a difference - great work - thumbs up!!
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I balanced the carbs today. They are indeed a pain to balance.
I was going to take it for a test ride after, but as soon as I got the tank and seat reinstalled, it started storming.
I was completely drenched by the time I got my tools put up.
Maybe tomorrow.
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I took the old beast for a test ride.
It backfires through the carbs under low-ish RPM (2500-3000), high load (accelerating), at about 1/4 throttle.
Also, the RPMs were hanging up when revved in neutral.
I lowered the needle clip one notch and adjusted the pilot screws out to 1 full turn from lightly seated.
Better, but it still stumbles and backfires on low-ish RPM/high load/part-throttle operation.
When it's up to speed, wide open throttle seems to be a beast.
It's getting to WOT that's the problem.
Seems like it's leaning out, but I'm lost as to where.
I'll check for vacuum leaks (haven't gotten around to that yet), but....
Any ideas?
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Pull your plugs out and check the colours, sounds like your fuel screw is still in to far, not letting enough fuel through causing it to run lean like you say, wind the fuel screw out in relation to your plug colour
Or try this also
https://m.youtube.com/watch?v=YXlFyrxeRlU
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Pull your plugs out and check the colours, sounds like your fuel screw is still in to far, not letting enough fuel through causing it to run lean like you say, wind the fuel screw out in relation to your plug colour
Or try this also
https://m.youtube.com/watch?v=YXlFyrxeRlU
Black, from idling rich, with a good sized white spot from running lean when I'm riding.
I've noticed that my K&N copy(?) filters from Dynoman dry out quickly. I oil them, and a day later, they are dry over about half of the surface of the gauze.
That will make them run lean, and I've noticed that the backfire issue gets progressively worse, as I'm riding and the filters dry out.
I'm thinking about making foam or cloth filter wraps to increase filtration and inlet restriction, to increase the vacuum signal at the jets and enrich the mixture.
So, does anyone make pod filters with paper filter material, or are gauze and foam my only options?
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Do you still have the original airbox?
Try that out to eliminate the pods as a problem.
It just may be the repro K&N filters are not up to scratch?
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The original airbox is a bit warped and doesn't seal very well.
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Is there a mate you could borrow a functional airbox from to test?
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Is there a mate you could borrow a functional airbox from to test?
Sadly, no.
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You’ll have to relocate to Australia😃
We have pleanty of spares
Amthough that would be a bit xsive ;D
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The original airbox is a bit warped and doesn't seal very well
Can you do rough sealing job for a trial or is it truly unservicable?
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You are all guilty of heading down a fox hole. Filters are probably drying out because they are getting splashed with fuel. Bike will run satisfactorily even without pods or air box so if you think there is an issue just leave them off for now but that is not your issue.
As was shown by Andy, these carbs run great as per fj1200 settings as out of the box. You are only complicating by changing needle settings and such.
Did you say yo7 still haven’t checked for leaks. Symptoms are classic air leak but it will be something simple. Check you have your timing plate on correctly. You really need to go back to basics. If it was running ok with the other carbs on go back to them to try. It can take a lot of work to solve an issue like this but it will eventually click and surface. Don’t keep complicating it more.
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Ditto Brett’s, Jaymo you’ve chosen a path only experts dare to tread,
If it’s sucking the oil out of the filters their either too close, or too small and too restrictive for the engine, an air box of some description will certainly help, it’s not a moto GP engine, it needs to suck still air from an even source and 4 pods won’t allow that, been down this track many years ago with CB 750’s and Z 900’s, they don’t work, sorry.
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I have determined that gasket got the exhaust crossover pipe (right before the mufflers) is leaking.
I don't remember how much it will affect running.
I'm going to pull the carbs and rubbers, remove the intake gaskets, check compression again, and reinstall the rubbers without the gaskets.
First, I will do another test for vacuum leak.
I tested for vacuum leaks with a propane torch (not lit, just propane flowing from the nozzle).
I discovered the exhaust crossover leak because I made and installed temporary oiled foam filter wraps.
Running it like that caused it to backfire out the exhaust (sometimes) upon acceleration, not deceleration.
Funny thing about the filters drying out, is that even if I don't run the engine at all after oiling them, the top halves of the filters will dry out in two or three days.
Going to remove the seat and tank, and set the tank in place of the seat (facing backwards), to allow better access to #2 & 3 intake boots for vacuum leak test.
Any recommendations for an aerosol spray product for checking for vacuum leaks?
Starting fluid? Carburetor cleaner? WD40?
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You’ll have to relocate to Australia😃
We have pleanty of spares
Amthough that would be a bit xsive ;D
If I could, I would.
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Funny thing about the filters drying out, is that even if I don't run the engine at all after oiling them, the top halves of the filters will dry out in two or three days
Hmmm, I'd be having a word with gravity and ask it to back off ;D
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Funny thing about the filters drying out, is that even if I don't run the engine at all after oiling them, the top halves of the filters will dry out in two or three days
Hmmm, I'd be having a word with gravity and ask it to back off ;D
I told gravity to do something I shan't repeat here. ;D
I did a compression test today. Sort of.
I did a cold compression test. I know I should've done it hot, but I had a senior moment.
Cold compression is 135 dry for all. Nice and uniform.
When I'd done a hot compression test before, they were 150 dry, didn't feel a need to do a wet test.
Back to today. Cylinders 2, 3, and 4 went up to 180 wet.
Cylinder 1 only went up to 150 wet.
So, intake valve sticking due to the crappy US ethanol gas, combined with the months the engine sat.
Or, I need to get a new valve cover gasket and check/shim the valves.
Possibly an exhaust valve leaking, but I should've had muffler explosions all the time, from cylinder number 1, if that were the case.
There is a definite possibility of some intake valve sticking and even ring sticking, since it sat for a good long time.
Considering all the carbon I've found in the cylinders, I wouldn't be surprised.
I've run into Mazda engines on Yale forklifts whose rings would stick if the engines sat for any length of time.
We'd squirt some automatic transmission fluid into the spark plug holes and that would free them up enough to run.
I shot about 10 CCs of Marvel Mystery Oil into each spark plug hole, after the "compression" test.
Then, I shot about 10 CCs of Marvel Mystery Oil into each intake runner.
I've got the battery on charge, because the battery is weak. Possible charging issues? Battery is only about a month old.
I'll let it sit overnight and fire it up.
Then, I may feed it some Seafoam or some Dexron ATF while running.
If any rings or valves are sticking or not seating due to deposits, that should free them up.
THEN, I'll check compression while the engine is warm.
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UPDATE: Ran the engine today. #3 and 4 are lean. Both (mostly #3) backfire at idle. Spraying carb cleaner into them (mostly #3) clears that up. Spraying it around the juncture of the intake boots and the cylinder head at 3 & 4 seemed to clear it up.
I'll check the intake bolts for looseness, when the engine is cool.
If that yields nothing, I'll pull all the intake boots and get rid of the gaskets. Probably will anyway.
Warm compression test resulted in 152 psi, dry, for 1, 2, and 3. 158 psi for 4.
4 also looks to be the most coked up. I don't see a need for a wet compression test at this time.
I believe I need to pull the cam cover and check valve clearances.
What's a good source for cam cover gaskets?
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Well it dose sound like it’s sucking air somewhere, compression is ok, mine only has around 145
across the board with a slight sound of piston slap. But, who cares! E-Bay used to have heaps of top end gasket sets at reasonable prices but have never seen just rocker cover gaskets, if all surfaces are nice & clean 3 Bond is all you need.
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Gaskets on intakes are bad news,, always end up failing,, remove them
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cam cover gaskets are still available from your scamaha dealer
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cam cover gaskets are still available from your scamaha dealer
The downside is the dealer will rape me on the price.
The upside is the gasket will be OEM.
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I bought Yamaha cam cover gasket a couple of weeks ago - $36.58
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Been very busy at work. Had some people quit and are very shorthanded.
Haven't gotten around to ordering cam cover gasket yet.
Yesterday, I removed the intake manifold gaskets and just used sealer between the intakes and the head.
Still having backfire at idle, but not at higher RPMs.
My old exhaust gas analyzer says 1&2 and 3&4 have and A/F ratio of 12.8:1 at idle and gets richer (up to 11.5:1 at higher RPMs) as engine speed increases.
What is the correct A/F ratio or A/F ratio range for these engines.
My next step is a valve clearance check.
If I have warped valves, I have a good friend who is an automotive machinist and charges me fairly.
I hope it doesn't come to that. If it does, I may get the big bore kit and get him to bore my cylinders.
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Just finished a set of carbs for Jonesy, Jaymo,
You,d swear the bottom end was about to fall apart all it was was air fuel screws balancing at the end of it they growled
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I picked up a leakdown tester and a new spark plug cleaner.
Now, I can check leakdown. And clean my spark plugs.
Waiting for cam cover gasket.
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Just finished a set of carbs for Jonesy, Jaymo,
You,d swear the bottom end was about to fall apart all it was was air fuel screws balancing at the end of it they growled
I bought my first XS very cheap because the guy said the engine was stuffed but all it needed was a carby tune and balance. The HiVo primary chain was banging on the crankcase because it was running so rough.
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Edit: Yep. Valves are tight. Will measure clearances again this weekend, just to confirm the numbers I got today.
Also, to measure the thickness of my shims so I can do some math and order the thicknesses I need.
Cam cover gasket, cam plugs, and exhaust gaskets arrived.
I got a leakdown tester, because I can always use one.
Warmed up the engine today and did a leakdown test.
Leakdown tester shows leakdown is less than 10%, and that's through the crank case.
However, I decided to cut out the middleman and connect my air compressor hose straight to the spark plug hole adapter.
When I did that, I got leakage past the exhaust valves.
So, I either have insufficient valve clearances, burned exhaust valves, warped/bent exhaust valves, or my valves and seats need to be lapped and/or recut.
FML.
Temps here are hovering right at 100 degrees F.
I'll wait until tomorrow morning to pull the cam cover and check clearances.
IF I need to replace valves and/or shims, do any of you know of any sources?
I'm in the USA, so USA sources would be great.
However, my front brake pistons came from the UK.
I'm not opposed to ordering parts from my brothers and sisters in AU, NZ, and the UK.
For that matter, I'll take my parts from anywhere in the world.