After doing my top end reseal, I put the bike back together. Now I'm getting an intermittent issue where I twist the throttle and the engine revs, but my speed slowly decreases. It's almost like the bike is in 1st gear when it is in 3rd. I can't tie it to any condition. It happens whether the gas is a week old or fresh. Any ideas of what I can check?
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R75/5 intermittent engine revs but no power
- Thread starter ARMYMUTT
- Start date
pglaves
#13338
I am not sure I understand. You say you twist the throttle, the engine revs, but speed decreases.
If you roll the throttle but the rpm of the engine does not increase and you slow down that is an engine issue.
If you roll the throttle and engine rpm goes up but speed does not or decreases that is a slipping clutch.
I didn't mess with the clutch at all. It has more freeplay than any of my other bikes. Seems to me that if the clutch was the issue, it would be associated with operating the clutch. This occurs while I'm just cruising down the road. It comes on, last for about 10 seconds, then goes away.
lmo1131
New member
Might, coincidentally, be the beginning of the main seal going away with oil glazing the clutch.
I'd go through the 'clutch adjusting' drill just to have peace of mind that THAT isn't the issue. Airhead clutch adjustment isn't intuitive.
Read > http://rubberchickenracinggarage.com/Downloads/Airhead Clutch Cable Replacement and Adjustment.pdf
I'd go through the 'clutch adjusting' drill just to have peace of mind that THAT isn't the issue. Airhead clutch adjustment isn't intuitive.
Read > http://rubberchickenracinggarage.com/Downloads/Airhead Clutch Cable Replacement and Adjustment.pdf
pglaves
#13338
I by chance happen to have a K75 that has a slipping clutch. Riding along at say 70 mph (the speed limit) in 5th gear, if I roll sharply on the throttle the engine rpm increases but the bike does not accelerate. Or simply riding along if I encounter a hill and roll on slightly the clutch slips. In forth gear the result is much diminished. This is typical of a clutch issue which comes down to basically two choices: the clutch disk is too thin, or the clutch is contaminated with a lubricant - gear oil, engine oil, or on early hydraulic clutch bikes, brake fluid.
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That's interesting, and is pretty similar to what is going on. Seems odd that it only occurred after I did the re-seal. Could it have been contaminated in someway during the procedure? I had the tranny replaced a decade ago. I wonder if the guy who did it screwed up the seal. Apparently, he did like to drink a lot while wrenching.
Clutch may be slipping as discussed by others but also confirm:
Rear wheel splines and spline cup rivets
Trans input shaft still has teeth
Spline cup at rear of drive shaft still firmly attached
It might be helpful if you further explain
"Top end reseal"
And
"Put the bike back together"
Top end reseal - changed the cylinder base gaskets, head gaskets, pushrod tube seals, o-rings in the head, and rocker cover gaskets. Put the bike back together - return all parts to their correct operating location at the appropriate torque.
Took the bike for a 60 mile ride, including some distance behind school buses making stops every 50 yards. Lots of stop and go. Had no issues this time around. I guess I'll just have to see if it happens again.
Could be an intake vacuum leaking pure air in and leaning out one or both carbs. Easy to cause with old hard rubber tubes or a loose vacuum port screw. Easy to cure by refitting parts. Might not even be aware of the leak.
Timing advance mechanism can stick intermittently messing with engine performance.
Sounds can be deceiving, misleading and confusing.
When I have a new symptom after service, I look at what I did and what's near to the recent work.
John
Timing advance mechanism can stick intermittently messing with engine performance.
Sounds can be deceiving, misleading and confusing.
When I have a new symptom after service, I look at what I did and what's near to the recent work.
John
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