Guide for adjusting the carb air/fuel mixture & Idle nee

Lostmycage · Post by **Lostmycage** » Thu Aug 21, 2008 3:32 am

Multi-pronged question here. I'm trying to get my Buddy just right....

Is there a definitive method of fine-tuning the carb's air/fuel mixture (not re-jetting, but adjusting the air/fuel mixture screw after a rejet)?

Is there any low-cost tachometers out there that can be used for getting the perfect idle range down?

Thanks and more thanks!

Post by **ericalm** » Wed Nov 11, 2009 6:11 am

This question is over a year old. But I'm reviving it. BUMP!

Skootz Kabootz · Post by **Skootz Kabootz** » Wed Nov 11, 2009 6:12 am

ericalm wrote:This question is over a year old. But I'm reviving it. BUMP!

Hey who the heck do you think you are??? The Admin or something???

Post by **ericalm** » Wed Nov 11, 2009 6:12 am

This is the malarky the service manual has for this:

Adjustment of fuel volume adjusting screws
1.After the engine is warm up, adjust the stopping screw throttle of throttle valve to the standard rpm. Idle rpm 1,700␣100rpm
2.Adjust the fuel volume adjusting screws to the highest stable rotation. This rotation value is the optimum setting of throttle
3.Fuel up for several times, make sure that the idle rpm is within the standard rpm. Repeat the above procedure if the idle rpm is unstable.

iwabj · Post by **iwabj** » Wed Nov 11, 2009 1:49 pm

Kaos · Post by **Kaos** » Wed Nov 11, 2009 2:54 pm

ericalm wrote:This is the malarky the service manual has for this:
Adjustment of fuel volume adjusting screws
1.After the engine is warm up, adjust the stopping screw throttle of throttle valve to the standard rpm. Idle rpm 1,700␣100rpm
2.Adjust the fuel volume adjusting screws to the highest stable rotation. This rotation value is the optimum setting of throttle
3.Fuel up for several times, make sure that the idle rpm is within the standard rpm. Repeat the above procedure if the idle rpm is unstable.

Heh, knowing how it should be done this gibberish is fairly close. I'll translate though.

1. Warm up your bike to operating temp.
2. Set your idle at a decent level.
3. Turn the idle mixture screw down till it ALMOST stalls.
4. Slowly turn the screw back up. It should begin to idle higher. If it starts to idle really high, pause and turn it down. Keep turning the screw up until it no longer increases idle.
5. Turn it down just a hair below it's highest idle point.
6. Rev it a few times, there should be no popping or hesitation. If it hesitates, turn it up a little, you're lean. If it pops when you let off, turn it down a bit you're rich.
7. take it for a ride.
8. Check the plug to be sure its a nice coffee color.

[email protected] · Post by **[email protected]** » Wed Nov 11, 2009 8:45 pm

I get a little pop pop but my plug is tan?

Kaos · Post by **Kaos** » Wed Nov 11, 2009 9:36 pm

[email protected] wrote:I get a little pop pop but my plug is tan?

How long did you ride it for? You could still be rich if it was only a short ride.

Your exhaust could also be leaking which will make a nearly identical popping noise.

[email protected] · Post by **[email protected]** » Wed Nov 11, 2009 10:55 pm

Kaos wrote:
[email protected] wrote:I get a little pop pop but my plug is tan?
How long did you ride it for? You could still be rich if it was only a short ride.

Your exhaust could also be leaking which will make a nearly identical popping noise.

good point mainly at 9 miles trips

Cheshire · Post by **Cheshire** » Mon May 03, 2010 3:17 am

Was reading up on this, and with all the tuning stuff lately, thought this could use a bump. Wonderful translation, Kaos.

Question: when you mention popping, are we talking backfire-"pow!" or a more subtle, gentle pop-pop? I've noticed a soft, breathy, occasional pop-pop when I'm coming to a stop or idling since I got the Prima pipe put on. Is this that pop that I should be avoiding?

Kaos · Post by **Kaos** » Mon May 03, 2010 1:20 pm

Cheshire wrote:Was reading up on this, and with all the tuning stuff lately, thought this could use a bump. Wonderful translation, Kaos.

Question: when you mention popping, are we talking backfire-"pow!" or a more subtle, gentle pop-pop? I've noticed a soft, breathy, occasional pop-pop when I'm coming to a stop or idling since I got the Prima pipe put on. Is this that pop that I should be avoiding?

Its usually more of a burbling pop, though if its really rich it can be a large pow. I'm talking after you release the throttle, not actually on acceleration.