lean or rich

[BobCarter]

In an effort to eliminate buzz I recently ground down the manifold, shimed the carbs, Adjusted A/F screws from stock 0 turns out to 1.5 turns, and synced the carbs.

All accross the board the engine runs significantly smoother. Above 5k or so it even feels a little more powerful. It idles smooth and all in all I'm 98% happy.

My question: Today was my first lengthy ride and I noticed that in higher gears below say...5k...that if I rolled on the throttle to wide open...it actually had less power than if I rolled to 50% throttle. Example: Cruising up hill at 50mph in 6th I roll the throttle 100% and it slowed down. However, if I back out of the throttle I can maintain speed.

Does this indicate that at WOT I am getting too much gas now for lower rpms, or maybe not enough. I can live with it the way it is because it runs so much smoother but I am more curious from the logic behind it. I tried adding choke to it too see if that changed at all but it didn't. Any thoughts?

[mammut89]

from the symptoms youre talking about id say youre running lean and should fix it as soon as possible. it can damage your pistons. to get another indication it should run even worse in cold weather so try it out by night just to verify.

[Psycho1]

.......... Adjusted A/F screws from stock 0 turns out to 1.5 turns........

This is a little confusing to read, the air fuel screws shouldn't have been set at 0 turns out from lightly seated in the first place, and should be set at 2 1/2 turns out from lightly seated as a starting point for best performance. Sounds like the engine is definetly running too lean.

[DClark]

This is a little confusing to read, the air fuel screws shouldn't have been set at 0 turns out from lightly seated in the first place, and should be set at 2 1/2 turns out from lightly seated as a starting point for best performance. Sounds like the engine is definetly running too lean.

That's what popped out at me. I'd take the bike out and wot asap before it is warmed up. If it runs better, it is too rich. If it is lean, I'd think you should hear some pops or have funky hanging idle. If it is lean, verify by covering at least 1/3 of the air box opening with duct tape. If it runs better, think lean.

[BobCarter]

2 of the 4 A/F screws were set all the way in and the other 2 were like 1/8th of a turn out. I had to drill the caps out so this had to be factory. I thought about going to 2.5 turns out but thought that may be too much since the bike had been running on 0 turns out.

More turns out equals more fuel? Sorry if I am not making sense.

[Psycho1]

yeah more turns out mean more fuel. It is also possibly that when your drill bit broke through the caps, it may have touched the screws just enough to turn them in all the way.

[BobCarter]

the drill most definitely didn't turn them in...I thought it was odd too. I guess I'll try 2.5 out and start from there

What would be symptoms of too many turns out?

[Psycho1]

2 1/2 should be good, if you notice a little burbling (uqiet popping) from the exhaust under decelleration, you may want to try another 1/4 turn out. 2 1/2 turn shouldn't be too rich unless someone really messed the jetting up with an aftermarket jet kit. Too many turns out and you might smell unburnt fuel when idling, notice some hesitation/stumbling when you twist the throttle from idle, and you could see some black smoke from the tailpipe. Extremely rich and it could backfire loudly as it burns fuel in the exhaust that it couldn't burn in the cylinders.

[Kreylyn]

0 turns was most definately not stock prior. 1 3/4 turns out would have been stock. If your was not set close to that, then SOMETHING happened to turn them in. The most common and logical reason would be as part of the removal of the caps over them that were drilled out, either by the drill... or by the tool/screw you used to pull the caps out. It doesnt' take alot to bump them and turn them.

Simple way to test it though... put them back at 0 turns and see if the bike will idle... I mean, if it did before.... even with what you did it would still idle a some.

I have a feeling it won't, at all at those settings...

Start with 2.5 turns, then tune them from there with the motor running.

Krey

[BobCarter]

I'll probably take it apart tomorrow and adjust it out. Are you guys able to adjust those screws on the bike....seems like you would have to adjust it with the carbs removed. Is there a trick?

Thanks again for letting me bounce this off you.

[Kreylyn]

I'll probably take it apart tomorrow and adjust it out. Are you guys able to adjust those screws on the bike....seems like you would have to adjust it with the carbs removed. Is there a trick?

Thanks again for letting me bounce this off you.

The "trick" would be to have the right special tool. Something like this...

http://www.motionpro.com/motorcycle/partno/08-0229

Otherwise, your looking at pulling them out of the engine boots and flipping the carbs/airbox up in the air enough to reach them and make your adjustments.

Krey

[mammut89]

that tool is so expensive

[BobCarter]

Well 3 turns out took care of it. I started at 2.5, then 2.75, and finally ended up at 3. It feels much better and no longer lags at low rpm WOT. Thanks for all your help.

I guess the only thing that makes sense is that The caps turned the screws when I drilled them out. I was extremely careful but I guess thats what caused them to be set at 0.

Thanks again!

[the wind]

that tool is so expensive

this is a little less.
New
Long Boy Fuel Screw Set
Having a hard time adjusting your fuel screws?
Don't have a multi-bent twisty windy screwdriver to find that "all important for cruise" Fuel Screw adjustment?
Factory Pro's 4 pc. "Long Boy" Fuel Screw Set allows the owner to reach in and quickly adjust your fuel screws for best cruise and idle quality.

[loudnlow7484]

I can adjust them with just a long flat screwdriver bit, but it takes some real contorting of my hands and exceptionally long fingers to do it. If you can reach this way, then mark the bit at 0 and 180 degrees so you can keep track by sight of how much you're turning it.