rocksternroll77
New member
Bings have been rebuilt, cables and linkage all good - when it's warmed up it keeps revving up. I have to use the brakes to slow the motor back to idle. Not sure what to look at.
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1975 R75/6 keeps revving steadily up -
- Thread starter rocksternroll77
- Start date
I guess you meant that you used the clutch to slow the engine...usually you slowly let out the clutch...with brakes on...to pull the engine down. If the RPM stays low after that, then that does point to the advance weights sticking "open" or out. Be sure to check all connections and ensure there's no air leaks between the carb and the head...spray some brake cleaner while engine is idling and listen for any RPM changes.
rocksternroll77
New member
yes, clutch and brake - I'll check out the weights and springs - I have looked at everything else - I think
stevenrankin
Active member
Idle
How hight does the idle increase? What are you setting the idle RPM at? Does the idle RPM drop down at any point or just stay high?
Some bikes will require a longer period of time to properly warm up to set idle RPM. It is best to adjust for initial starting and getting on the road and then when the bike is fully warmed up at operating temperature to set the idle RPM. RPM will increase as the bike warms up to a certain point but not drop down.
If the idle is increasing and decreasing while riding or in the shop, i would recheck your cable adjustment and then as suggested perhaps the springs and weights on the timing advance. St.
How hight does the idle increase? What are you setting the idle RPM at? Does the idle RPM drop down at any point or just stay high?
Some bikes will require a longer period of time to properly warm up to set idle RPM. It is best to adjust for initial starting and getting on the road and then when the bike is fully warmed up at operating temperature to set the idle RPM. RPM will increase as the bike warms up to a certain point but not drop down.
If the idle is increasing and decreasing while riding or in the shop, i would recheck your cable adjustment and then as suggested perhaps the springs and weights on the timing advance. St.
gregfeeler
Dances With Sheep
Were the O-rings around the butterfly shafts replaced as part of this rebuild? They can be an air leak source that can cause high idle as the bike warms up. A spray of starter fluid where these shafts exit the carb body can be a good diagnostic.
kbasa
Well-known member
Came here to type the same as Greg did.
gregfeeler
Dances With Sheep
bseg.
beemerchuck
Member
Experiencing the same problem with a 81 R100. Problem before and after carb rebuild.
With the carb tubes off I can slow the engine down my covering the carb throat briefly.
Eventually rises back up to about 2500.
Does the bean can ignition on the 81 also use mechanical weights and springs?
If so, I wonder if it would be the same springs as the earlier bikes?
With the carb tubes off I can slow the engine down my covering the carb throat briefly.
Eventually rises back up to about 2500.
Does the bean can ignition on the 81 also use mechanical weights and springs?
If so, I wonder if it would be the same springs as the earlier bikes?
Last edited:
beemerchuck
Member
Found the correct advance springs at Euromotoelectric.
