While at normal idle speed, frequently, without applying the throttle, the bike will automatically rev at a high constant rate.
I can only remedy this by turning off the engine and / or applying the choke.
I've adjusted the air mixture screw and also the idle screw, but this has not remedied the issue.
Can anyone assist with this?
I would say the answer from polar cycle is good...but if it is not the case....you may take a look at crankshaft seal..sometimes the primary compression is not good if cranks seal leaks and it make the bike running lean in gaz and having you're idle getting up sometimes.........check the transmission oil if its low in quantity even after replacing it recently (this means that you're transmission oil is getting burn by you're motor) and also remove the magneto cover to see if there is gaz accumulation in that area...if so that means the seal leaks on the magneto side.....
Testimonial: "After finally rebuilding the carbs and replacing the reeds and air filter, the problem was actually solved by replacing the crank seal. "
There have an air leak between the carb and the cylinder and/or the head and cylinder. Old hard / cracked rubber fittings and O rings are usually the problem. When extra air gets into the system it leans the fuel mix and the high idle is the result. It also means the engine runs hotter. Also, cracked or broken reeds can be a source.
On the oil leak, remove the laft engine covers. If the oil leak is coming from behind the flywheel then a bad seal is the source. The same is true if the leak is at the shift shaft seal or the sprocket shaft seal. If the leak is at the split on the center case, remove the flywheel and then use an impact driver to tighten all the casing screws on that side of the gearbox. That will usually stop any leaks. Hopefully there will not be a need to split the case and apply fresh sealer compound.
The choke problem is a plugged idle circuit. The pilot jet should be removed and cleaned along with the passage ways built into the carb. Often the jet is capped and the cap must be removed to then get at the jet. This is a touchy area on the carb. I can't find a diagram on your carb so I don't know how your carb is set up. Some jets just screw in tight. Some jets are adjustable as to the the number of turns and are individual to a single carb. Assuming yours is adjustable, count the number of turns exactly needed to turn the pilot jet inward until it LIGHTLY seats. Now remove the jet, clean the carb then screw the jet back in until it lightly seats and then back the screw outward the exact number of turns as it was originally set.
By the way, I am glad to hear the air leak problem was found and fixed.
×
Sounds like a vacuum leak somewhere. Make sure the carb boots are good, and any vacuum lines are good/connected.
3,574 views
Usually answered in minutes!
Thank you all for your feedback on this. What I have done so far is replace the reeds, the gasket between the carb and the head, adjusted the throttle and finally verified the overall wear of the carb.
The high revs have gone now and I can throttle up and down without issue, however I am now faced with another issue. I cannot keep the engine running without applying full choke. I have adjusted the mixture screw (1 3/4 turns out) and tried to locate a workable combination with the idle screw, but to no avail!
Additionally I am now leaking oil after warming the engine. Could this all be the result of a failing crankshaft gasket seal?
×