By joining you will help ensure that we can continue to provide this service
JOIN HERE!
R51/3 one carb will not idle down
-
- Posts: 141
- Joined: Fri Oct 27, 2006 3:00 am
R51/3 one carb will not idle down
- schrader7032
- Posts: 9053
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
- Has thanked: 3 times
- Been thanked: 36 times
Re: R51/3 one carb will not idle down
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
-
- Posts: 141
- Joined: Fri Oct 27, 2006 3:00 am
Re: R51/3 one carb will not idle down
- schrader7032
- Posts: 9053
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
- Has thanked: 3 times
- Been thanked: 36 times
Re: R51/3 one carb will not idle down
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
Re: R51/3 one carb will not idle down
https://cms.bmw-einzylinder.de/images/P ... 9S_WHB.pdf
You need to have 2mm slack between the inner and the outer cable.
Re: R51/3 one carb will not idle down
A poor mix (more air than gas) will increase idle, so this could be the problem.
Carb flange can warp as well, which causes air leaks.
https://w6rec.com/fix-intake-leaks/
1974 R90S
-
- Posts: 141
- Joined: Fri Oct 27, 2006 3:00 am
Re: R51/3 one carb will not idle down
Re: R51/3 one carb will not idle down
I think, in order to go to the next step, we would need to know exactly what you have done and how the issue happens.
The numbers in brackets are referring to the pics at bmwbike.com table 13_0829 subtable 13.09 (carburetors for Boxer)
Check both cables to the carbs, if they are wired smoothly from the throttle grip to the carb and there is no sharp curve whatsoever. Check also the spring (6) if it has enough strength to snap back the throttle grip once you let it go.
Then, do as Kurt already said: Important is to do standard adjustment to the carb. For the first step I use very small cable ties on both sides and fiddle them between the carb slide and the lower part of the body. Turn out the slide stop screw (13 adjuster) so that the slides sits on the body. Then slowly turn it back in, until the cable tie starts to tremble. One half turn further in, should be a good start. You do this on both sides. Then (cable ties back under both slides) you loosen the counter nuts (4 nut) on the carb bodies cap in order to adjust the adjuster (3). Fix one first, so that the cable play at the adjuster (3) is roughly 2mm. Then adjust the second one so that once you turn the throttle, you see both cable ties tremble at the same time. Once that is done, make sure that you still have enough cable play also on the recently adjusted side (roughly 2mm). All of that can be done without even starting the engine and it will give you a good start for your synchronization of the carbs later once warmed up.
Now, you say, all of that is done but still one side doesn't idle properly. Test both cylinders separately (make sure you put a spark plug into the pulled socket and lay it on the cylinder so that it's grounded). Start the bike on the active cylinder and see if it reacts to the throttle like it should. Also check if the engine reacts to a change of the air mix screw (16). Test both cylinders separately.
report back your findings.
good luck
Klaus
-
- Posts: 200
- Joined: Fri Oct 27, 2006 3:00 am
- Has thanked: 1 time
Re: R51/3 one carb will not idle down
Re: R51/3 one carb will not idle down
Mike
69 R60/2 76 R90S 78 R100RS
70 Triumph w/Spirit Eagle Sidecar