35hp omc carb ?'s

[JSM86]

Can anyone tell me if the newer carbs mid to late 90's on the 30/35 is any better than the older carbs? It is a completely different carb body than the older ones. I don't have either to measure or compare but from comparing part numbers I see most older 35 carbs had 59d jets and the newer ones have 67d's, maybe a little larger bore?? But I did find some of the late 80's carbs had 70d's. Lol. I see a bunch race these little motors so if anyone could help me out I would appreciate it. Also if anyone has either carb they would sell let me know. Thanks

[JohnsonM50]

The carb alone might make a little difference depending on what was on before. Some have plastic venturi inserts that restrict the carb & some motors have a small opening in the intake. Ive tried different carbs quite a bit. Theres 4 sizes of the typical single barrel aluminum body carb Ive seen so far. The largest has a 1 1/2" throat & 1 1/2" manifold opening. [not from a 31.8ci] These so far seem to be a bit too much. The motor will go well top speed but not faster & be at a loss mid-range. The proper size at 1 1/2 throat & 1 3/8 behind the venturi work best, look for one with the largest venturi you can find & try jets. Ive made a couple to be adjustable hi-speed, no advantage to report except that it can be dialed w/o changing jets. When you get what your looking for, look at tune specs. If your motor is timed different than a 35 it would be worth doing whatever the specs are to see if better. Always be sure the carb is opening up all the way, Its possible that an ex owner messed with the econo-mizer. Good Luck.