Can somebody tell me where it is, or tell me what number it is on the Yamaha exploded view of the carb?

I have a 1999 Wolverine and I put the FST intake on it and took the baffle/spark arrestor out of the exhaust and I am trying to fine tune it. I put a 145 main in( I have not had a chance to run it wide open since I live in the city) I move the c-clip down one but that made it worse (a lot of popping and back firing on deceleration) so I moved it back to stock position of the middle groove. I have the air lid on and there seems to be a stumble right off idle and some popping between 1/4 and 1/2 throttle. Revving it full sounds great and seems to respond well at the higher rpms but that is sitting still?

Any help would be great. The 145 jet is Yamaha, and I have a stock needle in it.

 

The air fuel screw is right next to the main jet and pilot jet...you can access it after you take off the hex bolt on the bottom of the carb. unless it's in a different spot than the YFZ. Also try moving the clip up from stock.

 

You're on the right track. Your stumble is most likely from a lean transition from the pilot circuit. There are 2 holes in the bottom of the float bowl. One of them has the pilot screw. You want to turn it out a little. It's a bear to see and get to without some special screwdrivers. You might want to loosen the carb form the boot and rotate it, make a minor adjustment, then put everything back in place and try it.

 

ketchupYFZ450, I do not think they are the same? I will look though. Moving the clip up will lean it out more than stock, is that what I should do? I thought with the new intake it would need to be made richer?

cruiser3, So is the pilot screw the same as the fuel/air screw? How much is a little, 1/2 turn?

 

you would want to make it richer, because it it taking in more air with an aftermarket airfilter, and you want to adjust the mixture screw while it is on the bike. if you know anyone with an ega that would really help, but not everyone has one. and motion pro has a 90 degree screwdriver for adjusting mixture screws, if that is any help.

 

Yeah, by moving it up I meant 3 to 4 or 4 to 5...not leaner...sorry for not being more clear.

 

I still do not know where the mixture screw is. Is it the same as the idle screw?

 

Before you start monkeying with the clip location on the needle, adjust the pilot/mixture screw in the bottom the carb. 1/2 turn is a lot. Do the adjustment in 1/8 turns

 

No It not the same as the idle screw, It is Underneath the carbs, there are 2 small holes on each carb just past the idle screw, However if you dont remove the carbs you need a screwdriver that has a 90* angle and gearing to turn it, not sure what they are called but your local shop should have them If you know exactly how much you want it turned have them do it......... takes a whole 5 seconds and give the guy 5 bucks. otherwise remove the carbs and flip em ' right there you cant miss on each carb is a screw turn in all the way first then back out as necessary

 

The screw is under the carb. It's really a pain just to get to it. I just ordered an easy adjust fuel screw off of ebay for about $20 US. Supposedly, it extends the screw so it can be adjusted without removing the carb. I found it on ebay. Can't wait to try it.