Stutter when I rev

[jhusman]

My bike runs fine but when I give it some gas there is a little "Stutter" before I have take up. Once it jerks the rpms up to about 2K RPM, it has fine power, but it is a little draggy on the take off.

Any thoughts as to how to fix this? I'm running stock exhausts, so that isn't it.

[Annie's Boyfriend]

I have noticed that Annie rides better, with much less stuttering when I use a High octane fuel.

Yes, Annie stutters too, but after getting my carbs and poits done, it has improved much

It seems to dissapear when the engine is warm.

grtz,

Bart

[jhusman]

I only use a high octane fuel. Maybe I should give a thought to putting a carb cleaner in.

[Annie's Boyfriend]

Could work, I have also noticed that a richer mixture, when the choke is not completely closed, improves the handling when she's cold.

The guys from my local shop, who are real pro's, couldn't find anything wrong

So I guess I will have to live with a little knobjigglin' while driving.

Bart

[Marko]

Your idle mix is to lean and or the accelerator pump is not giving a big enoughshot. I have been a motorcycle mechanic for over 20 years and it still supprises me to hear about fuel octane and carb idle mix adjustment and syncronising. Fact: Octane is the fuels resistance to detonation and nothing else. The reason your bike may run a little better with it is because you are getting slightly better gas. Now as far as adjusting your carbs go the procedure in the manuals be it a Factory, Clymer or Haynes using the lean idle drop method or RPM based adjustment is not good. That method came about when the EPA got involved with motorcycle emmisions. It is designed to make the motor run as lean as possible to reduce emmisions. If you want your motor to run at its best a richer setting is needed. Most bikes run well with 2 1/2 to 3 1/2 turns out on the fuel screws. On my stock wing plug reading confirms that it likes all fuel screws at 2 1/2 out. All fuel screws should be set the same. Syncing the carbs should be done after setting the fuel screws. fuel screws should not be adjusted when syncing.

[Annie's Boyfriend]

Thanks for that Marko, is this something I can do as a newbie in enginemechanics.
I don't even own a manual yet

I think I know wich screws you mean, my mechanic pointed them out for me.
Should they be turned the same distance, regardless of their position ??

I guess they should be turned left to increase the saturation of the fuelmixture ??

(I like to take dumb questions I guess )

Bart

[Marko]

There are no stupid questions. The fuel screws are on the bottom of the carb right next to the float bowls facing downward. Some carbs have a limiter cap attached to the screw so you can only turn it 7/8th's of a turn and only leaner. You would need to remove the stop on the limiter or the stop on the carb body.You can remove the cap on the fuel screw but you risk breaking the screw. I use a dremel tool with a cut off wheel to remove the stop from the screw that way nothing needs to come apart. Once that is done (if needed), you would one screw at a time turn it in (clockwise) until it LIGHTLY bottoms and then back out 2 1/2 complete turns. It does not matter where they end up facing but they must be the same number of turns out. Then check carb sync. I cant tell you if you can do it or not but you should have a manual handy.

[Annie's Boyfriend]

Thanks Marko, that explanation is just what I need to fix that problem I have with Annie.

Bart