Bonneville America Forums Forums Technical Forums General Tech Am I too lean?

Ok, I'm fairly sure I am too lean, but let me know what you think...

Changes I've made recently:
Sorty pipes
Nology Coils, wires, silver plugs

The bike has always popped on decel, and continues to do so, but today... after about 45 minutes of riding, the engine started to skip... and even cut-out a couple of times. After playing with it a bit, I noticed that it only happens at low throttle. I just ordered a set of mains (Dinqua's jetting calc called for 155s for my setup).

Thanks, y'all.
Lance

What do you have for a setup now in terms of mains, pilot jet, needles....? Did you change anything after you installed the Freak?

The freak was on when I got the bike. The previous owner was a moto-rental place, so I'd imagine they jetted it properly... then again, I could be wrong.

Not sure what jets are on it now... haven't wanted to go through the tear-down just to explore... Maybe I'll have to.

It doesn't take long to remove the bowls and check. If you haven't changed the screws that secure the bowls with allen head ones, make sure you use a good quality philips screwdriver. You can then tell what main jets you have. I was able to tell what pilots I had with a mirror and small flashlight.

Yes access to the jets is from the underside or the bowl side of the carbs.

Hey ya Lance... I too didn't know anything about carbs, until this year. What I did was pull them first so I could really look at them. You know... hold them in my hand, take them apart and get to know where and what everything is. Now, when I work with them in place I know exactly what to expect when I pull the bowls, or remove the top covers. It was a worthwhile exercise for me... just throwing it out there for ya!

Ok... pulled them... put 'em... took a look around.. put them back on. I didn't mess with anything as it's getting late, but here's what I now know.
The mains say "Factory 160k" and the pilots say 42. Soooo... that comes out pretty close to what the jetting calc calls for (155 to 157.5) from what I remember (haven't re-checked it as it doesn't work in WINE and I don't have a windows box at home).

My bike did exactly the same thing for a while, I remember checking jets whatnot. One of the freak pods were loose, I tightened that and the bike haven't stuttered since...

Here is what I bet you would find on a dyno, you are probably way lean until around 1/2 throttle then you go rich after 1/2 throttle. I would bump the main down to the 155 and the pilot up to a 45. Be sure to balance and adjust the mixture screws after the change.

sounds like a miss to me. Too lean will cause popping on decel and cause it to fall on its face if you dump the clutch and nail it. low throttle falls in the pilot jet range. My brothers bike acted like that and it was a coil. you can get a bad coil even a new one. His bike warmed up and ran nicely till you gave it some throttle then it would go to missing and cutting like crazy. It wouldnt do it cold but give it 35 or 45 minutes. Just some fuel for thought. If ya don't mind the bad pun.

i'd check the carb rubber thingies......all those rubber stoppers that are placed when the ai is removed.
it sounds like you have an air leak.

Popping on decel? If jets are correct or close, just turn your air mixture screws out 1/4 turn at a time till popping stops.

This was a huge topic back in spring of 2003. I installed open Septres, correct jets, unifilter, adjusted idle, balanced carbs. The popping on decel was ghastly. Turned screws out to 4 1/2+ turns and it quit.

Later took my 03 BA in for 500 mile first service. The dealership put the bike on the co2 machine and adjusted the screws in. I picked it up, ran like a bat from hell, as it did when I brought it in. The first stop light I hit on the way home the decel sounded like WWII. Pulled over and reajusted the screws, no popping. I had installed the thumb screws, expensive, but well worth it, as are the carb allen head bolt kit, if you clean, adjust and balance carbs on a reg basis.

Good luck.

Many here have unplugged the TPS which effectively eliminates popping on decel.

If jetted right there should be some popping a decel but not too much.