Rev's drop slowly when warmed up

[peepingtom]

Hi, i have a problem with my 100gs that runs ok when cold but when warmed up the revs take a few seconds (3 to 4) before the revs go down to normal tick over speed. This is annoying ,especially when changing gear as the revs dont drop immediatly. Any ideas as i really want to get it running sweetly.

 

[DrFarkoff]

When did you last check your valve clearances?

 

[Rob Farmer]

Sounds like a mixture/setting up issue. I had something similar though that turned out to be the weights in the advance retard unit sticking and not returning to the retarded position. That was all the time though.

 

[Kenny]

Not enough play in your throttle cables and maybe tickover a tad to high

 

[peepingtom]

Not enough play in your throttle cables and maybe tickover a tad to high

actually i think you could be right kenny im off out to try it out as they are fairly tight.
Jaythro ive only just got the bike so ive not done the valve yet.

Rob i will see if its the tight cables before i check the mixture settings

thanks every1 off to test . report back soon

 

[cookie]

butterfly(s) hanging on a tight cable or basic sync issue i reckon.

 

[peepingtom]

The cables actually werent that tight after all but i loosed them off more and sadly it had no effect
better get the haynes out and see how to set the carbs up

 

[DrFarkoff]

check valve clearances if it only does it when warm!

 

[sl2]

Mixture is wrong/Ticking over to high

 

[SJRoome]

Hi

Here is a list of things to check, some of which have been covered by others:

1. throttle cables have enough clearance, are not overly worn or stiff

2. ignition advance is correct and not sticking

3. valve clearances

4. the bike was hot, after say 10 miles riding, when you set the carbs. Mixture and carb synch are correct.

5. That you haven't got a vacuum leak. To test listen for hisses or spray carb cleaner over each area of the outside of the carb and the attached hoses and see if the idle speed changes.

Steve

 

[peepingtom]

check valve clearances if it only does it when warm!

yes I WILL check em Jaythro

sl2 the tickover is fine and will check mixture soon

SJRoome i will go through your list but i dont think i will be able to do much untill the weekend now.

everyone it great of you to help.....better than a Haynes manual!!

 

[(RIP) Kaister]

air leak at inlet rubbers ?

 

[mikyh]

Carburetors

Remember those are of the CV kind. the throttle opens a butterfly, but the slide/needle are actuated by what the carburetor feel by comparing pressures before and after slider.
Here lies your foes.
Miky

 

[SJRoome]

Hi

I forgot one :

6. Check that the slides are not sticking. Remove the tubing on the intake side of the carbs and lift the slides half and inch or so with a clean finger. They should drop completely in half a second or so.


Steve

 

[John Armstrong]

Just a thought, if only one carb is slow to return back to idle, won't it mean the bike runs a bit roughly until they're at the same "power" setting?

My 100GS does it sometimes, but not all. Seems most prevalent after a long high power run.