engine races

jesmed · Post by **jesmed** » Sat May 19, 2007 12:26 pm

Joe,

Thanks for the suggestion. Regarding terminology, if you have an old Honda parts list, you'll see that Honda calls these "air screws." I'm just using their words.

The experts have told me that the "racing" problem is likely caused by excess air getting through/past the carbs, not excess fuel, so I don't see how dropping the needles helps...but I'll give it a try next time I open up the carbs.

Jesse

LOUD MOUSE · Post by **LOUD MOUSE** » Sat May 19, 2007 1:48 pm

Well I'm sort of an expert and I'd bet your carb slides are not raising and lowering at the same time and that one is adjusted higher than the other by the slide screw or the cable.
Either or both of these will cause what you describe.
Also the "AIR SCREW" shouldn't be MORE THAN 1 1/4 +- open from bottom.. ...........lm

jesmed wrote:Joe,

Thanks for the suggestion. Regarding terminology, if you have an old Honda parts list, you'll see that Honda calls these "air screws." I'm just using their words.

The experts have told me that the "racing" problem is likely caused by excess air getting through/past the carbs, not excess fuel, so I don't see how dropping the needles helps...but I'll give it a try next time I open up the carbs.

Jesse

jesmed · Post by **jesmed** » Sat May 19, 2007 2:27 pm

Ed, as far as I'm concerned, you're definitely an expert! I've tried everything you and Bill Silver have suggested, including checking the slide heights and synchronization, but I'll try that again too...I had the air screws set at around 3/4 turns open before the racing problem began...

Jesse

LOUD MOUSE · Post by **LOUD MOUSE** » Sat May 19, 2007 3:42 pm

OK. Twist both SLIDE SCREWS out so far that the slides BOTTOM OUT.
Now start the engine and check for idle down. .............lm

jesmed wrote:Ed, as far as I'm concerned, you're definitely an expert! I've tried everything you and Bill Silver have suggested, including checking the slide heights and synchronization, but I'll try that again too...I had the air screws set at around 3/4 turns open before the racing problem began...

Jesse

jesmed · Post by **jesmed** » Sat May 19, 2007 4:08 pm

Yup, I've tried that already with this process:

1. Back idle set screws all the way out so slides hit bottom.
2. Set both air screws to 1 turn open.
3. Start engine, rev to 4000 rpm or so and roll throttle back to idle.
4. When engine races and won't return to idle, kill ignition, close air screws 1/4 turn and try again.
5. Gradually turn idle set screws in just enough to keep from stalling at idle.
6. Continue gradually closing air screws and adjusting idle set screws as above.

At the end of this process, I always wind up with the air screws closed completely and the idle set screws in just enough to keep from stalling at idle...this is absolutely the only setting that forces the engine to return to idle...

LOUD MOUSE · Post by **LOUD MOUSE** » Sat May 19, 2007 7:58 pm

Go get a 2007 new YAMAHA. ...............lm

jesmed wrote:Yup, I've tried that already with this process:

1. Back idle set screws all the way out so slides hit bottom.
2. Set both air screws to 1 turn open.
3. Start engine, rev to 4000 rpm or so and roll throttle back to idle.
4. When engine races and won't return to idle, kill ignition, close air screws 1/4 turn and try again.
5. Gradually turn idle set screws in just enough to keep from stalling at idle.
6. Continue gradually closing air screws and adjusting idle set screws as above.

At the end of this process, I always wind up with the air screws closed completely and the idle set screws in just enough to keep from stalling at idle...this is absolutely the only setting that forces the engine to return to idle...

jesmed · Post by **jesmed** » Sat May 19, 2007 9:44 pm

No, never! I'll never surrender!