Idling issues

Mason Campbell /

Have a 1980 Sparta Buddy with a Sachs 504. MLM intake and a SHA 15.15 carb. And a gianelli circuit pipe.

The carb still needs down jetted, waiting on those to get in either Monday or Tuesday. So the tune is off for sure.

However idling has become an issue. It’ll idle for about anywhere from 10 seconds to 30 seconds before it just dies out. I have the idle screw turned all the way in and I’ve already rechecked all the gaskets and decomp plug. Everything is snug so I don’t feel like it’s an air leak.

I’ve never worked with a SHA 15.15 before, but I know it’s limited on tuning capability. Will re jetting help my idling issue?

Re: Idling issues

Did you spray test it?

Re: Idling issues

I have been off MA for a long time. Just posted a question today. Don’t know if this is good advice or will get me blown up, but here goes...

If your WOT jetting is good, your needle feels good all through it’s throttle range, and all you need it idle leaned a bit? I had a bored out stock Bing that I just filed away a bit of material on the bottom of the slide near the atomizer. There’s a wiki about that or some posts. Reducing vacuum around the atomizer opening without raising the entire slide. Fixed my rich idle/fouled plug at stop light problem.

Different carb and stuff though. So, don’t take my word for it. Just something to consider.

Re: Idling issues

Mason Campbell /

No I haven't, and just to make sure i have the spray test right. The bottle of water checking for arcing on my electrical correct? I bought this bike stripped all my wires are clean but I'll double check.

Re: Idling issues

Mason Campbell /

> Todd S Wrote:

> -------------------------------------------------------

> Did you spray test it?

Nevermind, there are 2 spray tests people run. I'm still relatively new to this moped world. I'll run the test and see if I've got a vacuum leak anywhere.

Re: Idling issues

what main jet size? if its to big your idle will load up, get smaller bits, also angled or notched slide would help down low, to lean idle, air filter affects it as well.

Re: Idling issues

Mason Campbell /

It has a 70 in it right now. New smaller jets should be in tomorrow or Tuesday. And the air filter is just the stock metal mesh that comes on the SHA. The idle screw has been all the way in since the beginning. It idled the first two days no problem with the idle screw in tight. But hopefully the new jets help.

Re: Idling issues

its rich then, take a look at your plug, oily n black? fouled? u can test by taking off the filter all together, and run with just the black cap, or no cap. that'll lean everything up and confirm your running rich, or experiment with the number of screens, more screens equals richer, im guessing 3 screen black cap and a 64. of course get a couple new plugs as well, maybe a higher temp ones too.

Re: Idling issues

Mason Campbell /

> pat splat Wrote:

> -------------------------------------------------------

> its rich then, take a look at your plug, oily n black? fouled? u can

> test by taking off the filter all together, and run with just the black

> cap, or no cap. that'll lean everything up and confirm your running

> rich, or experiment with the number of screens, more screens equals

> richer, im guessing 3 screen black cap and a 64. of course get a couple

> new plugs as well, maybe a higher temp ones too.

So there isn't a very noticeable difference with no mesh or no cap. I may be just running that rich. I mean it bogs out in the low range at full throttle. Once she revs up a bit you can tell it's running better. I have a new plug ready to go. Just waiting to use it with the new jets so I can get more accurate readings. Once I get it dialed in with the carb stock air filter I'll either upgrade carbs at a later date or experiment with thinner mesh filters for the SHA. I just wasn't sure if my main jet in this carb would effect my idling.

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