puch maxi spark plug problem

hello guys,

i have a puch maxi and my problem is that its spark plug is sooty and black after 50 km of usage, than the moped stops, and i have to change the spark plug to a new one. with the new one, a can use it for a couple of days again, but than it stops again.

i know the spark plug should be brown, and i also tried with an ngk b5hs and b6hs, so i dont really know what should be the problem.

thanks for any useful ideas!

Re: puch maxi spark plug problem

Michael Thomas /

Your running too rich.

Re: puch maxi spark plug problem

^ that.

So basically, when your carb is mixing the fuel and air, you have too much fuel in the mix. The engine can't burn it all cleanly, so you get the black deposits on your spark plug. This can be fixed by either increasing air flow or reducing the amount of fuel that gets mixed in.

If your bike is stock, start by checking the air filter and making sure it isn't dirty/blocked. If your bike is stock and you think a previous owner may have tried to make it go faster, they may have drilled out the jet, which would cause you to get too much fuel. You wouldn't usually be able to tell if the jet had been drilled just by looking at it, so if you suspect that someone may have messed with it, you might just want to get a new one. And while you're looking at the jet, report back with the number (size) stamped on the side.

You could also get a high-flow air filter, which would increase airflow and probably solve the problem. Just be sure to check that it isn't running too lean after you do that.

Re: puch maxi spark plug problem

thanks for the advices,

so i cleaned the airfilter and the whole carb also, checked the jet in it and its not drilled, its size is absolutely the factory size. the needle is in the lowest position.

but the spark plug still getting black as it can be in a minute after the start, and there is a new thing: the idle has to be so high, or else the engine stops when i pull the throttle, and it doesnt have any power. but if i set the screw it works perfectly, for a day or to till it kills the sparkplug...

any idea? its really getting on my nerves.. thanks a lot!

Re: puch maxi spark plug problem

Downhill Harvey (OFMC) /

float needle leaking, and WFFF

Re: puch maxi spark plug problem

By "the needle is in the lowest position", do you mean the clip is in the lowest position? Move the clip up to lean out the low RPM fuel mix.

Re: puch maxi spark plug problem

no, my bad, the clip is in the uppest, so the needle can be in the deepest position

Re: puch maxi spark plug problem

DPC Colin Fortier /

whats your oil mixture ratio ?

Re: puch maxi spark plug problem

1:50

Re: puch maxi spark plug problem

Tri-ped Dave O.D.B. /

still haven't told us what jet size is in there

Re: puch maxi spark plug problem

64 written on it

Re: puch maxi spark plug problem

you need new seals in your engine. mine does the same shit

need a rebuild

Re: puch maxi spark plug problem

Matthew DG /

my noob magnum is the twin to this. same exact problems - runs too rich, needle all the way down, bing 14 w 62 jet, e50 stock cc's. Runs fine open throttle but idle way too fast and can't slow it down without stalling and it fouls plugs. good air filter, float needle checked rechecked and looks good. I'm not finding air leaks... spark plugs black and wet all the time, except when I run it fast - so long as I don't stop or slow down I can ride it.

Re: puch maxi spark plug problem

Try running a warmer plug

Re: puch maxi spark plug problem

i tried ngk b5hs which is the warmest but also killed in 2 days.

Re: puch maxi spark plug problem

DPC Colin Fortier /

I hope you mean 50:1 not 1;50

Re: puch maxi spark plug problem

I wonder if the compression is too high... Are you running a high compression head? Also, I wonder how much carbon is built up in the exhaust? Good luck.

Re: puch maxi spark plug problem

Chris Driscoll /

Still need to know more information. 64 jet in what size carb/intake? Stock airbox or high flow filter? Are you running a stock exhaust, or aftermarket pipe? Can't tell you if a 64 jet is correct without knowing all of that.

Re: puch maxi spark plug problem

- bing 14 carb

- original airbox, but i cleaned it

- stock exhaust pipe

Re: puch maxi spark plug problem

yeah, 5 liters of fuel 0,1 liter of 2T oil

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