Bike cutting out a little

[Beau254]

I have a UFO 4/1 (UFO makes the Quadzilla while Cobra makes the 4-into-4 slip-on, not a complete exhaust) and whenever I have a stumble off-idle, I check the gas tank, the fuel filter (replace it) and just remove the carbs, open them, and put 'em into the ultrasonic tank, and reassemble. The two brass jets have to come-out of each of the jet blocks' tunnels, and the main jets, too. Blow-out the passageways before reassembly, of course.

Ya, I thought about flushing the tank & changing the fuel filter. But I have one of those in-line see-thru fuel filters & it didn’t look very dirty @ all. I only saw a couple specs of residue in it.

 

[Traumahawk]

Well, I did the main Jet & choke Jet carb clean with spray carb cleaner with spray nosel spout while running @ idle & @ high idle. Then drained the bowls & sprayed them all out with carb cleaner as well. Then put in all fresh gas with Seafoam conditioner. Then went out & ran the Piss out of it. Lol.
Definitely is idling better now & running smoother. But it still has that low initial acceleration stumble. I’m thinking it’s due to how it’s jetted for top end. (Stage-7 Jet kit with aftermarket Quadzilla exhaust & K&N air filter.) Anyone else with a modified bike experience this?

Have you done a "shotgun" procedure on it? Ive have REALLY good luck doing a shotgun, while removing PAJ#2, for a full blast of air. Also FYI, people in the past have destroyed coasting enricheners, buy just spraying carb cleaner in the wrong spot.

https://vmax.lvlhead.com/tips/shotgun.htm

 

[Beau254]

I’m not sure what you mean by “Shotgun” procedure? Or PAJ#2.
I followed Pea Shooter’s Vmax carb clean off YouTube.

 

[Traumahawk]

I’m not sure what you mean by “Shotgun” procedure? Or PAJ#2.
I followed Pea Shooter’s Vmax carb clean off YouTube.

I posted a link (hyperlink) to the procedure. On the site, it explains what PAJ#2 is (Primary air jet.....#2), and there are pics to walk you thru everything.

 

[Beau254]

I posted a link (hyperlink) to the procedure. On the site, it explains what PAJ#2 is (Primary air jet.....#2), and there are pics to walk you thru everything.

Thanks. I missed the link.

 

[Beau254]

Really good info. But I don’t experience any of the symptoms mentioned. I think it’s just how mine is jetted for top end. Because it idles fine & is very responsive. If you crack the throttle back it takes off like a Jet. It just has a tiny sputter right @ initial take off. Same spot every time.

 

[Traumahawk]

Really good info. But I don’t experience any of the symptoms mentioned. I think it’s just how mine is jetted for top end. Because it idles fine & is very responsive. If you crack the throttle back it takes off like a Jet. It just has a tiny sputter right @ initial take off. Same spot every time.

The pilot jets (which are cleared when you do a shotgun), are the carb circuits that are being used when you take off, and are just running around town. The main jets do supply fuel everywhere, but dont really come into play (full use) until 7000 rpm and up.

When was the last time the carbs were synchronized?