SpeedRacer,

I feel the same way about the 10mm carbs. I like 'em...the one that works. I don't know if I just got hold of a bad batch. If I did not have one that works as it should, I would have given it up and asked them to trade for the 8mm. However, whenever I take one of the 60's and tach with the 8mm and then the 10mm back to back, I usually get a higher static reading with the 10mm. I have used the Jett Stream, Mac's header and pipe, Rossi muffler, Rossi minipipe, bolt on TT muffler, etc. onvarious Rossi's. The fact that one carb works keeps me hoping to get them all corrected, otherwise as mentioned I would have opted out for the 8mm.

I had the red jet carb off my SJ 50 this afternoon and tried to fit it to the Rossi. They both have 16mm necks but the Jett is oversized just enough to not fit into the Rossi. Polishing would probably get it to fit. This is an 8.5mm carb. Might be another option if needed. I don't know what Dub sells the carbs for.

Jim,

I have an old blackhead that is a shortstroke and another that is not a blackhead but is a shortstroke as well. They are both ringed engines. I believe the current Rossi's have a silver head on the 40 and 60's, black head on the 45, and a red head on the 53. I believe this has changed through the years.

Most if not all the older Rossi carbs were 8mm and hadtwo part HS needles.

Dave

The 10mm carb that functions correctly is getting more than adequate pressure with the Jett Stream to run overly rich. There is no fuel draw issue with this carburetor. The correct setting uses one half of the useable threads on theHS needle. The engine has been on two planes with very consistant operation. The only condition where the engine cannot be richened enough is with the carbs that cannot be adjusted properly and the idle needle has to be closed completely.

I hope Rossi's solution works. I will keep everyone posted.

Danny