Thread: 1.5 N/S...any fuel flow issues?
08-29-2007, 11:42 AM #1
1.5 N/S...any fuel flow issues?
This isn't a Yamaha specific question, but know you guys have experience here. The problem I'm having is fuel is leaking from the booster at lower RPMs where the motor vibrates badly. I'm running 2.0 N/S w/ a 115g spring. I was thinking of trying a 1.8 or even a 1.5 N/S to try to get it to stop, but some feel that it wont feed the motor under heavy loads. I know you Yami guys do this all the time. Just looking for some feedback. Carbs are Full Spectrum 48mm with two external fuel pumps, BTW. Brazina says to try a 1.8...I guess he ought to know, as they are his carbs. This is on a tripple pipe 1200 Poo, BTW.
08-29-2007, 12:52 PM #2
I've heard of this before with 2.0's. 1.5's have been successfully used on skis going 80+, so they will probably be fine for you. Consider switching, and installing the proper springs and setting popoff.
Oops - just realized this isn't a GPR. Never mind...
08-29-2007, 01:25 PM #3
08-29-2007, 01:30 PM #4
08-29-2007, 01:55 PM #5
08-30-2007, 08:41 AM #6
1.5s would be fine as far as flow goes but you would have to readjust your popoff. Have the 2.0s been sitting for a while? The needles can get a wear ring in them not shutting the fuel all the way off, especially with the 115 gram springs. If so it may just need new needles to get the dribbling under control.
Most tripples will knock a a little fuel out at idle due to the vibration, usually doesn't hurt much.
Another thing to try would be doubleing the check valve on the kidney.
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