revs increase to 3000 when warm R100GS

Windmill John

Windmill John

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Just done my first trip to work on this bike; 28 miles.
Half way throught the journey, I noticed the tickover was getting towards 2000rpm. Towards the end of the journey, when I pulled the clutch in to change down, the bike revved at about 3000 rpm.
I cannot see any obvious leak areas.
Besides leaks, what could be causing this increase?

Cheers

John
 
Just had this with JustStans bike.

Cured with a new pair of throttle cables:thumb2
 
+1

Just had a similar thing with m PD. One core of the inner cable had come adrift and wedged in the outer.
 
When the idle was set was the bike fully warmed up ?
 
Idle not checked initially

Only just got bike. First two immediate jobs were front disk and noisy left pot top end.
Reshimmed on the weekend, had a short test ride, only 4 miles and that was better.
When I rode the bike home from the seller, 50 miles, I didn't have the problem.
Obviously, I had the rockers off for reshimming, but did loosen and retighten cylinder head to correct torque as well as reset tappets.
Just been out to the bike and I noticed that the right hand internal nylon sleeving on the throttle cable was down to the carb; I could shove it up.
Throttles seem fine without starting the bike, but maybe because it is 2 hours since riding to work.
 
Mine was doing that till Steptoe worked his magic, it was a combination of poor carb settings, idle mix and tickover.

Shep
 
check in this order.
1-throttle cables
2-miss tuned carbs, due to not warm when don
3-air leak, : choke cover not tight, or spigots
4-timing adv, weights in the bean can are sticking or springs are weak.

i had one that was set perfect, take it down the road and nothing, ride it the next day rev was 2500rpms carbs rebuilt, ect. turns out it was the springs in the bean can. the timing advance was hung up.
 
Thanks guys

Ordered new throttle cables, will check carbs when fitting and see how it goes:thumb
Might check advance at the same time.

Cheers
John
 
INCREASED IDLE

Check the rubber sleeves between the carb outlet and cylinder head. They deteriorate with age/ fuel / oil and can become porous when hot. They are cheap to replace anyway.
I had a similar problem on my R90 when hot. After carb refurbish and lots of tinkering, it was eventually traced to the LH sleeve allowing air in when hot!! When I replaced them, the adjustment required to balance the carbs correctly was huge - that shows how much the sleeve had deteriorated and I had compensated for this air leak by adjustment. Now the idle is rock solid no matter how hot it gets.
Try the simple stuff first?
Cheers
Eng
:thumb2
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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