Revs not shutting down

[Lucky_Lou]

As mentioned in Montmils of carbs and diaphragms my revs keep sticking at 3000rpmish when in neutral im sure the problem is the butterflies not seating if i tweek em with my finger the revs drop.
The springs on the flat top bings are quite short and i am sure they are the origonal ones i was wondering if i should change them...the cables are new so they should not be affecting it.
Does anyone know if there is a stronger aftermarket spring out there
Ta Lou

[montmil]

Hey, Lou. Sticky butterflys?  ..."im sure the problem is the butterflies not seating if i tweek em with my finger the revs drop."

During your carb o'haul, did you remove the butterfly valve and shaft? I understand from other posts that it may be helpful to lightly secure the valve just snug enough to get it centered in the venturi. Shine a torch from the opposite side and look for equal gaps all 'round the valve. Adjust as necessary. Then, final tighten the two screws.

When I rebuilt my 32mm Bings, I discovered one spring was about one-inch shorter than the other! Well, I gave 'er a tug and made it the same length as the longer one. Longer is good  

Monte

[bruce_launceston]

Hi Lou
This is what I did with mine.
First thing is to ensure the butterfly is the right way up and around, if you are happy it is then continue.
Loosen the 2 small screws that lock the butterfly to the shaft.
Hold a small amount of pressure on the actuating lever on the end of the shaft to close the butterfly and tap around the edge of the buttefly (on the face) with a small screwdriver until it seats properly.
Keep the pressure on the lever and tighten the screws, Check again with the torch, they should seal almost lightproof.
Hope this helps, it made all the difference in getting my bike balanced and idling slow when warm.

Cheers Bruce

[montmil]

Yeah, like Bruce sez.   Monte

[ambrose78]

Did the new springs / alignment of the butterflies fix the problem?

Other possibilities for high idle revs may be

*ignition timing - If the retard mechanism in the bean can is stuck/sticking periodically in the advanced position your idle revs will remain highish 2500-3000rpm range.

*Air filter - What condition is your air filter in? That can affect the air fuel mix which will affect how the bike runs.

[Lucky_Lou]

Did the new springs / alignment of the butterflies fix the problem?

Other possibilities for high idle revs may be

*ignition timing - If the retard mechanism in the bean can is stuck/sticking periodically in the advanced position your idle revs will remain highish 2500-3000rpm range.

*Air filter - What condition is your air filter in? That can affect the air fuel mix which will affect how the bike runs.

intresting one that the air filter is new how do i check if the timing is sticking???
Lou

[ambrose78]

how do i check if the timing is sticking???

There are a couple of things you can do.

The easy diagnose test
one is to put bike in gear when running and with the brake on, slip the clutch to lower the revs to around 1000rpm or so
pull clutch in again.  
Do the revs jump back up to 3000? Or do they stay low as they should? If they stay low until you rev the bike again it is definately an area to looks at - probably needing a bit of lubrication of the mechanism. If the revs jump back to 3000rpm it less likely to be the timing but the possibility remains that it could be jammed in the advanced position.

Next is to check the timing
The normal way to set/check timing is using a timing light. To check the timing it is best with a timing strobe light. Theres a little rubber plug next to the oil filler which you remove to see the timing marks. Connect the timing light and aim it into the hole and you should see the marks (From recollection there are two marks an "I" (or 1?) and a "Z" (or 2?). When at idle revs the "I" should be roughly in the middle of the window. By about 3000rpm ish the "z" should be middle of the window.

Though if your bike statying at 3000 rpm this probably will just show the z mark all the time anyway. You may need a trustworthy friend to help by applying the brake and slipping the clutch in gear to drop the revs to around 1000rpm mark while you check the timing. Obviously safety being of concern here.

[ambrose78]

Another thought sprung to mind - are the throttle idle screws backed off all the way on both bings? that could be affecting it.

[Lucky_Lou]

Probebly not going to get chance to sort this till next week....ive stripped and rebuilt the carbs..everything but the dreaded throttle shafts seals(ok im a coward) which i am sure are ok tried spraying the shaft with WD40 to see if it altered the revs it didnt so presumabley thats ok i set the throttle stops 5 thou clear before setting the cables i will stobe the ignition to see if the A/R unit is working and report back.
Lou