Forum bmwbike.com

My brother is restoring an R69S motor that has been fitted with R60 pistons and R 60 carburettors, as the elderly owner wants a softer state of tune for his machine. Can anyone advise please on the preferred carburettors settings for such a "conversion"? Main jet? Needle jet? Throttle slide level?

Thanks

Philip V.

Philip,
Did you ever get info on the carburetors ? I don't have any info, but I sure need some regarding my '62 R 27. Could you steer me to someone who knows ?
Ed

Well, the R69S carbs were 26mm while the R60/2 (did you mean the /2?) carbs were 24mm. Might help if you provide the carb numbers for the replacement carbs. But for the 151/152 carbs for an R60/2, the main jet is a 125, the needle jet is 1308, and the idle jet is 35. The clip position is 3rd from the top.

If you meant an R60 carbs 95/96, the main jet is 105, the needle jet is 1208/6 (whatever that means), and the idle jet is the same and so is the clip position.

The jet needle for R60 and R60/2 carbs is the same at 255.

Kurt in S.A.

Here's a web page with a scan of the carb settings from Bing.

Kurt in S.A.

What are the Timing markings on a R 26 flywheel, like S, F etc. what do they indicate when aligned to the mark on the window.

S is the static timing point...you adjust the points so that they open when the S-mark is in the middle of the window. The F-mark is the full advance point. When running and using a timing light, the F-mark will show in the window and remain there as the RPMs increase beyond a certain RPM...about 2500 or 3000 RPM depending on the model and engine.

The engine rotates clockwise when viewed from the front. The first mark to see when rotating the engine is the F-mark. Next is the S-mark...there maybe be a line above and below the S-mark representing small degrees around it. Finally, not long after the S-mark, the single mark shows which represents when the engine is at Top Dead Center.

Kurt in S.A.