Hello There
My 1985 K100 has this horriable kicking inside it when I ride below 2800 rpm.
Bring the clutch in and it goes away.
Ride above 2800 rpm and it goes away.
Acclerating though gears no problem.

Got crawling traffic here.
I.m actally doing a overlander trip from LA and are 300km south Of Rio ( Brazil ) so hope its just sugar cane juice and Shell V-power only will solve it.

thank you for any help

Hi Fellow Kiwi,
First off much more info required, has this just started after a fill up? Have you owned the bike for a while or just bought it?
Regards,
K-BIKE

Hello

I,ve done over 45,000 km since I bought it.
Its now got something like 85,000 miles now on it.
Actually don,t think its do do with fuel , just don,t want it too be the gear box or clutch as fixxing or getting parts where I am may take a long time , time I don,t have.
I used too be able too ride it at low rev,s before but now its like it wants to stall when below 2800 rpm. In whatever gear.
A real cluck cluck shaking the bike in its guts which is avoided by either dropping down a gear or raising the revs,s.
A bike shop put a new clutch put in it after the engine oil seal leaked onto it about 20,000 km ago.
Its been there before quite some time ago but only slightly. Not always been there.
Like it wants to stall when riding along when rev,s drop to that level. Seemed a little better today otherwise I,m riding it differently.
Got that motion when you sometimes stall , only when I,m riding.

thank you for any help

Hi kiwi70,
Have you checked for air leaks with carburettor cleaner (the inflammable type) or propane or butane gas. I could envisage your problem being caused by a big air leak such as a crack in the rubber joiners between the throttle body and the intake manifolds. Check that first as it is easy to check with the cleaner or gas then we can check the throttle air flow meter is working properly.
Regards,
K-BIKE

What is the color of your spark plugs?
Here is few tips:
The first being an air leak as K-Bike pointed.

The second could be a leaky injector. Here is the explanation:
One injector is leaking and send too much gas (on one cylinder). when riding under 2800rpm, the vane in the airbox doesn't allow enough air to compensate this excess of gas. (bad ratio air/gas for this cylinder). When you twist the throttle, your engine sucks more air and it re-establish the balance.

Another problem could be the TPS (idle switch at the end of the butterfly ramp). Just try to disconnect it to see if it makes a difference.

Bert

Hello

Well thanks heaps guys, my bikes right back too normal.
I cut off the ends of a couple of vacum pipes that were cracked.
Test rode it and the engine felt like it had a little more response but still wanted too kick itself in its guts.

Then I disconected that switch at the end of the butterramp and blocked off a vacum pipe.
Took it for a test ride and it had solved the problem 98%.

Can,t believe that such a little switch that BMW put on it could cause problems like the bike had.
I read that later models didn,t have that switch as it has proved not worthwhile.

Thanks Guys , youse have saved me a lot of possiable drama and possiable money.

Your switch may be full of water or it may not have been set correctly.
Un-tight the 2 screws, and rotate the switch clockwise.
With the throttle off and the engine off, rotate it counter clockwise until your hear the "click" when the switch contacts. tight the screws and try the bike again. (You have to be close to the switch to hear it) You may want to use an ohm meter to be more precise.

Bert

Hello Crazy Frog

How are you?

I took that switch off and it was as clean on the inside as the day it went on . The switch screws were quite tight so i don,t think it had moved, but I re-tighten it on the click.
Now the bike can ( did some times before ) cut out on me when its hot on the road like the fuel has suddenly been turned off. Stop the motor. Start it again and it can ride for a little while further and will try again too cut out but sometimes I manger too keep it going.
Just before I got too where I am it was stopping every kilometre and seemed too be on two cylinders. Going to pull it apart in the morning.

No longer has that kicking in the guts , has had a slight kick when warming up in idle.

Bit of dribble . Bought the Bike at a BMW dealer for US$3800 ,if I left Brazil without it I,d have to pay something like US$1400 in tax.
Secondly a oil filter at a dealer costs around US$75 ( R$125) and a fuel filter around US$80 (R$135)


regards Kiwi70

Check all earth grounds under the tank and all connections treat all of them with DeOxit. My guess is the problem will resolve it self. One place that really needs treating is the plug and socket from the tank.
Regards,
K-BIKE

Hello
Reckon I found the main culbrit.
One of the clamps around the a manifold was really loose ,had a build up of a oily substance around it.Three of the clamps could be tighten, one took a lot of turns.
Needed to buy a longer screw driver , rear cyclinder.
Had that plug and socket problem before.
All the earths I checked and cleaned still.
Getting to known my way around the bike.
Shouldn,t be any more cutting out when amongst trucks and bus,s in five lanes, ( Sao Paulo ).

thanks again guys