XS1100 AUSTRALIA
XS1100 Topics => Workshop => Topic started by: Dagoose on March 27, 2011, 10:22:57 AM
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Hey Gang
Just after a bit of info if you don't mind
Since gettin the bike, I've noticed an occasional, but annoying backfiring/popping in the exhaust. Thought it may be that bike just needed a good ride. Sadly such has not improved :'(
Now I've confirmed this:
1. All exh pipes are hot.
2. Fuel is good as I changed it out.
3. Under heavy load, the popping seems to disappear.
Now from memory, the popping must be unburnt fuel in the exhaust exploding. So I am guessing that such must be a result of
1. Plug misfiring every now and then and letting fuel into pipes.
2. Just running way too rich.
Maybe lean, but pulling the choke on, the engine died. If it was lean, I'm guessing it would have improved with choke on.
Now the carbs were synched not long before I got the bike, so I'm reluctant to redo this. I probably should do a plug chop and hava look.
What do you guys think, Fuel or Ignition issue? Thanks in advance :)
Cheers
Glenn
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Hello Glen how long has it been since you checked the shim clearances,the popping may be caused by a couple of tight shims
Regards dale
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in my experience this is caused by a leaky manifold gasket, and/or muffler to engine pipe connection ..
B
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Thanks Coe and Aussi, I'll definitely check both items, thanks guys :)
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I had something similar as you described happen on a run out to Mount Isa, though it wasn't apparent while riding. It was when I pulled up for refuelling and the bike was idling after a hot run ( not fanging it, about 42-44 degrees c) it would pop occasionally out of the left pipe. I took it to the local (Mt Isa) dealer to get it looked at, and they said they had no gear to work on an old bike like that?? WTF???? I took it pretty steady on the ride home, but had no probs.
Got back to Brissie and my guys said that an exhaust valve had nearly zero clearance and that's what would've caused the popping at high temperatures. One shim change and all was good.
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what do you call an "ocassional pop",,
whilst on a steady rate of speed-------or------- only when descellerating to a stop, under gear shifting,-----------or---------when idling ,, hot or cold
when you say all pipes are hot,, are they all the same heat,, easiest way to check is put some spit on your finger and touch the pipes at the same point, that way you'll know which pot is cold, and the prob child,
the other guys have given you the items to check, now you have the way to check which one
even tho you say fueling is good, check the plug for colour, maybe a slight tweek of slide needles is warranted,, air filter's clean ay??
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Apart from Exhaust Valve clearance being incorrect, the popping can also be caused by a leak in your exhaust somehwere. Check that your exhaust is noice & toight everywhere before you need to go through the hassle of checking your velve clearances.
Cheers
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mate, if the popping is on deceleration you are almost certainly sucking air.
check your intake and exhuast manifolds (have you got new ehaust gaskets in or are they just the old crushed ones reused?), and your ehaust system joints.
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Mine used to do the same thing when backing off the throttlle just before having to go to reserve....maybe you got a float height/fuel level problem
Jonesy.