Too Rich!

My spark plug indicates that my air/fuel mix is too rich, and I was wondering how to make it leaner... I've got a Puch Magnum MK2 with a Bing carb, and I was wondering if there were any easy tricks to this, or if I had to re-jet or what... any info would be awesome... (I'm really hoping I don't have to re-jet, getting the float bowl off is the biggest pain in the ass for me for some reason...)

Re: Too Rich!

simply asjust the air/fuel mixture screw....

i dont know how many turns you have to do...but this is the problem

Re: Too Rich!

Mike Ellison /

Hmmm... I wish that _was_ the problem, but the Bing carbs don't have an air/fuel mix screw... at least, not listed on this explosion of it... http://www.mopedsonline.com/m-o-l/shopping_center/parts_and_accessories/bing.htm

Re: Too Rich!

Bing has an idle adjustment screw,2-1/2 turn out from tight or til back wheel spins slow.if your running rich "wet" more air is needed,check your air filter inside the black air box it could need a good cleaning,or replace "dry black"then it could be your oil gas mix.

Re: Too Rich!

number 14 is the idle adjustment screw in that picture.. same difference.. turn it in to make it lean and out to make it rich..

First screw it in all the way till you feel it stop. Don't turn it in hard or you will damage the tip of the needle.

Backing it out about 1.5 to 2 turns is a good place to start.. Make further adjustments, if necessary, with an 1/8 turn at a time, in or out, and test ride between adjustments.

Re: Too Rich!

whoops.. i see you are running rich and misread it to mean a rich idle..

You know the cure for rich idle..

If you are running rich pull the slide and needle out (#3 and 4) and clip the needle to a higher groove. This will allow less gas to get in during mid range operation. If you are rich at wide open throttle, you need a smaller main jet.

Its a big "IF" unless you have tested the bike properly.. that means running at a certain speed for a quarter mile or so and killiing the engine at that speed.. coast to a stop and remove the spark plug and see whats up.. At some speeds you may be rich. The cure for richness at that speed is different, depending on what speed it is.

Re: Too Rich!

Mike Ellison /

Hey Joe, thanks for the help. Do you, off-hand, know how to get the main jet out of the carb? I've opened the float bowl, and I see the jet and the thing that holds it, but I don't know if it should be pulled out or unscrewed or what... any help would be awesome.

Re: Too Rich!

Doesn't the jet have a screw slot in the end? Just to be clear, theres a tube extending into the float bowl and at the end is the main jet.. (#1 on that exploded view of the carb)

every jet i ever saw was screwed in.. when you put it back in, screw it in snug and then just a tiny bit more.. don't crank down on it... i think they are soft brass..

why are you taking that jet out? are you just cleaning things or did you already do a lean/rich test at top speed?

Re: Too Rich!

Mike Ellison /

When I go full-throttle, it bogs down and dies on me... and when I drop it down to below full, it kicks back in. So, I'd assume that this is a jetting problem... also, a small engine repair-guy told me that if the things that were happening happened, I should check my jetting.

Also, I guessed that it was a screw thing, and so I tried to unscrew it, but it wasn't budging... I think the stupid thing's too dirty right now... so I'm going to soak it for a couple days in some cleaner, then try again... hopefully, it'll be a little more forgiving next time around. Thanks for the help!

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