Just giving Tony's (RETRO) RH a good going over after it was purchased from Melbourne Recently.
Rebuilt the carbs, put a kit through them, replaced #3 carb (broken posts). The engine now responds smoothly to throttle control (while under no load). The road test highlighted a flat spot from 1000 - 3000 RPM then it took off like a cut snake.
The bike came with a 4 - 1 system which had had the internals removed from the muffler. The muffler was repacked and put back on the bike. This I believe was causing the flat spot down low due to jets and stuff beyond my knowledge so I put my spare 4 -2 system on and the result was instantaneous. Smooth throttle response through the full rev range. I am a fan of the original as Mr Yamaha built it solution.
The next thing to fix will be the "jumping into gear" problem.
The probable cause could be the 5th gear pinion rubbing against the 5th gear wheel. You can feel through the selector shaft a definite rub, like a missing spacer?
or worn selector fork??? When the revs increase in neutral the bike violently jumps into gear
The only way to confirm this will be a flip and look see of the gear box. In the next week or so.
I'll take photos and update this post accordingly. I'll also bring the offending bits with me to Wellington as part of the car park clinics we hold on the Saturday afternoon.
Other than this problem the bike is a very good clean original example of the RH and could be more original than Lil Scotty's
Eddy
78E
78E twin DJP
81H (project 3131)
81RH Daily ride
81RH ($200 special barn find)
82P (future father son project)
