Forum bmwbike.com

The needle affects midrange throttle, and 4 is too rich, but would not affect full throttle mixture. The 4.00 rear tire is oversize for your mid-60s final drive ratio, and could have the effect of not allowing the engine to reach full rpms before the top speed is drag-limited by wind resistance. I f...

The throttle will not spring shut by design, as there is a drag spring built into the throttle grip. However, the throttle on my R27 is very easy and smooth to open and close, and will close itself weakly if released. The slide spring in the carb should be intact and strong. Once my throttle acted s...

If by /2 fender you mean Earles fork, that fender will not fit the telescopic fork. The telescopic US forks have their own fender. Here's my US fork bike and a spare fender:
http://www.flickr.com/photos/roundel/se ... 098524282/

I think the forks are interchangeable. The /5 internal piston has an additional oil hole to soften the action, a 3-piece bushing vs 1-piece to reduce stiction, and a better bearing adjustment and locking system. These are upgrades that don't affect the fit. I am not sure if the /5 forks can carry th...

I have not heard of tappets (lifters) becoming worn and causing noise. I have both refaced and replaced some lifters whose faces became pitted, but this is not the wear to which you refer.

From the information given, possibly there is piston seizure (Kolbenfresser). I would remove the gas tank, remove the cylinder head, look at the condition of the exposed cylinder walls, and use a block of wood try to move the piston downward. If the piston can be moved, remove the cylinder. If the p...

"... We do not have a BMW motor cycle dealer here and hence there is no way of getting the black improvised paint... Black heat resistant paint is not available here and hence I can’t help." Black heat resistant paint is available in ordinary hardware and auto supply stores in the US, so s...

Singles do run hot. What makes you think your R26 is overheating beyond what is normal for it? When I first restored my R27 in 1999, Mark Huggett made a remark in this forum about deep sumps being more important for singles because they ran hotter than twins. I asked why, and Mark replied with a for...

If a valve spring is fouling the inside of a rocker arm, does not that indicate severe valve seat recession (wear)? If washers are added, will not that allow the seat to recess (wear) to the point that the remnant of the seat may fall out and damage the cylinder? Rather than add washers, it may be t...

I have never heard of this conversion. It cannot be done with parts alone. It would also require welding and machining on both the aluminum engine case and the frame, which is probably too difficult. My R27 engine shakes in its rubber mounts at idle and low rpm, but the impulses into the frame are m...