Originally Posted by jjwithers
I just rebuilt a R75/5 from the ground up and added the Siebenrock piston/cyl kit that supposedly is a 20% increase in power. + Lightened flywheel.
My R75/5 carbs were a bit too worn and the choke was leaking a bit and i couldn't get a good idle.
I got a set of Very good condition 32mm carbs that were from a R80GS. I took them apart and cleaned just a wee bit of crud out.
While they are apart, I'm wondering if I should leave the jetting and needle positions the same?
Or should I put the R75 idle/needle/main's in the new carbs?
The bike will supposedly be close to a R90 in power due to the piston kit but I'm not sure how the jets will effect or help/hurt the bike.
Ultimately, i want something reliable.
Does anybody have the Bing guide for jetting?
Thanks in advance.
Replace the following;
Slide needles BMW #13 11 1 337 692
#266 slide needle jets BMW #13 11 1 261 702
#45 idle jets BMW #13 11 1 336 924
#135 main jets BMW #13 11 1 256 612
That should be a great starting point if not spot on.