Engine rev's high when rebound the main stand??

[Super8504T]

Ok.. when the scooter is on the main center stand.. the rpm's are very low and at the norm.. the headlights dim as they do when the engine is that low. But when I push the scooter off the center stand and onto the floor so that the back wheel is on the floor.. the rpm's increase to a high idle and wants to creep the scooter forward slowly. Also the headlights stay on bright and dont dim as they should do because of the high rpm's. However sometimes the rev's will drop down for about 5-6 seconds.. but then they will go back up to high idle again.. its like the engine doesnt know how to idle properly.

[Super8504T]

Also can I just add in that when I come to a mildly sharp stop say at junctions or traffic lights. The rpm's drop down really low to cutting out point and sometimes if the engine is cold it will cut out. But if it doesnt cut out the rpm's will after about 5-6 seconds come back up to high idle where it wants to "creep" the scooter forward again.

[sidthesloth]

I don't know if this would do it but what about a low float level? while the scooter is idling on the main stand try tipping it back to level and see if the idle increases, if you sit on the scoot and lean back that should do it, just hold the rear brake on for safety. as I said, I don't know if it will work but worth a try.

[wordslinger]

...good idea sid...

[sidthesloth]

Yeah, if it is not pulling the throttle cable then it must be something else, with the revs dropping after a quick stop, may be something like that.

[Super8504T]

Ok sid.. just tell me what to do again.. didnt quite understand

[sidthesloth]

With the scoot idling on the main stand tip the scoot back so the front wheel is off the ground. Hold the rear brake on so the scoot don't take off. Ie the idle increases it may be something to do with the float level. I don't know if it will do anything but may be wortha try.

[zombie]

The more you post the more I think it is a vacuum leak. Have someone do a $40.00 leak down test for you. Or at least install a vacuum gauge, and monitor it as the trouble happens.

[art]

Not sure if this will help,not familiur with the super 8,but the old honda's were famous for this with the carb mounted in the front of the cylinder.While off the ground there  is less vibration,when the tire hits the ground it would shake the carb boot letting in air,making it almost imposible to tune if you had an air leak,plus the fact they cracked quite often.I would check that all is tight at the boot to carb,if that don't do it try to look for leeks.Carb cleaner sprayed around the boot should retard your idle if you have an air leak.If you do you can duct tape for a temp fix,but replacing boot is your best option.Good luck

[Super8504T]

Just tried tipping the scooter back and forth on the main stand but the low idle doesnt alter, its fine on the stand, its when any weight is put on the back wheel. I think it maybe a vaccum leak as zombie said. What can I have a look at/do myself without getting anybody to look at it as its going in for a service in two weeks so I'm not going to bother with it too much, but just wondered if theres anything I can do myself in the meantime?

[art]

I'd try the carb cleaner around the boot,while it is Idleing high,any change in idle will tell you there is a leak.You can usually trace it right to the spot if it exists.Good luck

[wordslinger]

..this is very strange

..i was sure it was something stretching the throttle cable, because he said he could see the cable pull the throttle assembly on the carb when he dropped iy off the stand...


..wtf??

[Super8504T]

Yeah ok were all getting a bit muddled now 

At first I thought the throttle cable was being pulled very very slightly but now I know it certainly isnt. I am quite sure it is the clutch shoe that is worn since the bike has now done 8600km it might be time for a new one. Because the problem only happens when any weight is put on the back wheel, where the clutch is and so as it says in the manual if it tends to creep forward.. it could be the clutch shoe that is worn.

[Super8504T]

I cant see it being a vacuum leak because why does it not do it all the time even when on the stand? It only happens when any weigh is applied to the back wheel so my suspicion is that the clutch shoe is worn

[wordslinger]

since the bike has now done 8600km it might be time for a new one.

..i have 49,000 km on my original clutch and it is just fine...forty-nine thousand....

..over 30,000 miles...

..8600 isn't even broken in good yet...lol..