30years Posted January 13, 2011 Report Share Posted January 13, 2011 I've got 34mm mikini's and with the other stuff i've got done to my quad, i think it should be preforming better. The mikuni's came with 260 mains, and i'm all the way up to 350 mains, and it's still lean. I was wondering if the carbs are too big for a motor that is only 40 over? Is it getting way too much air? Should i go back to stock 26's, or something between stock and the 34's? Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted January 14, 2011 Report Share Posted January 14, 2011 What else have you done to your banshee? Are we supposed to just guess? Have you done a leak-down test and ruled out possible air leaks? We need WAY more info to help you out. Quote Link to comment Share on other sites More sharing options...
Coupelx Posted January 14, 2011 Report Share Posted January 14, 2011 over-boring an engine during rebuilds is not considered a modification. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted January 14, 2011 Report Share Posted January 14, 2011 over-boring an engine during rebuilds is not considered a modification. What does that have to do with helping answer the guys question? Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted January 14, 2011 Report Share Posted January 14, 2011 Quote Link to comment Share on other sites More sharing options...
30years Posted January 14, 2011 Author Report Share Posted January 14, 2011 I've got what are supposed to be ported pistons from vito's. K&N with no lid, the 34mm round slide mikuni's, aftermarket intake with built in crossover, v3 reeds, cool head with 19cc domes, fmf sst's with matching silencers, and + 4 timing. Still have stock gearing. As far as a leak down test, not sure what that is? Just spraying down everything in front of the air box with carb and choke cleaner to test for leaks??? Also having a problem with the head pipes getting to seal 100% at the jugs. The o rings just don't seem to be fat enough! Thanks guys! Quote Link to comment Share on other sites More sharing options...
gotta_goatsfast Posted January 14, 2011 Report Share Posted January 14, 2011 Carbs are on the large side of the scale, but your quad will still run. I second a leak-down test. There's a thread pinned in the "Banshee repairs and mods" section that will walk you through it. Quote Link to comment Share on other sites More sharing options...
30years Posted January 14, 2011 Author Report Share Posted January 14, 2011 I've got what are supposed to be ported pistons from vito's. K&N with no lid, the 34mm round slide mikuni's, aftermarket intake with built in crossover, v3 reeds, cool head with 19cc domes, fmf sst's with matching silencers, and + 4 timing. Still have stock gearing. As far as a leak down test, not sure what that is? Just spraying down everything in front of the air box with carb and choke cleaner to test for leaks??? Also having a problem with the head pipes getting to seal 100% at the jugs. The o rings just don't seem to be fat enough! Thanks guys! Sorry, I just read the write up on making yourself a leak down tester!!! Quote Link to comment Share on other sites More sharing options...
Coupelx Posted January 14, 2011 Report Share Posted January 14, 2011 What does that have to do with helping answer the guys question? . I was wondering if the carbs are too big for a motor that is only 40 over? everything if he is under the idea that it requires bigger carbs. Quote Link to comment Share on other sites More sharing options...
speedfreek1 Posted January 14, 2011 Report Share Posted January 14, 2011 is your engine ported Quote Link to comment Share on other sites More sharing options...
30years Posted January 14, 2011 Author Report Share Posted January 14, 2011 is your engine ported not ported at all Quote Link to comment Share on other sites More sharing options...
Coupelx Posted January 14, 2011 Report Share Posted January 14, 2011 not ported at all you would probably be happier with a set of stock or maybe 28mm carbs. ive seen alot of stock carb bikes run very hard. my bike came with 28mm carbs when i bought it and running against bikes with similar mods i dont feel they give me much of an advantage other than they are easier to rejet. Quote Link to comment Share on other sites More sharing options...
RZBansheeMan Posted January 14, 2011 Report Share Posted January 14, 2011 Those carbs are TOO big for that set up..... stcokers will support a solid 70hp motor, I would definitely go for some of those...they are cheap and plentiful. Mike Quote Link to comment Share on other sites More sharing options...
06specialedition Posted January 14, 2011 Report Share Posted January 14, 2011 Do a leak down test. Then try a set of stockers....I bet it helps ALOT. I still run stock carbs on my ported shee with more mods than you, and this thing rips hard. Stock carbs are good up too about 70-75HP and your bike isn't even close to that in HP numbers IMO. -Zach Quote Link to comment Share on other sites More sharing options...
Blewbyu Posted January 15, 2011 Report Share Posted January 15, 2011 Im just throwing this out there since Im not too familiar with mikuni's. Are you shur they arent meant to run with a fuel pump? Did you buy these from someone you was running them on there banshee? This may explain your lean issue Quote Link to comment Share on other sites More sharing options...
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