Bad Ignition

15 Bing, 78 jet, New 70cc K-star, Tecno Estoril,70cc Hi-comp head, E50 with Stock electrics/stock points. When I run an 80 jet on my Puch it sounds like 4 stroking at WOT ( I've tried an 86 jet and worked my way down) I've checked the plug and its black with carbon and oily. I've then moved down to a 78 jet and I no longer 4 stroke. It runs nicely at WOT ( I dont really bother with break in for kits) when I check the plug its still oily and black. I mean the bike runs fantastic with great takeoff. I'm just concerned that I might be running to lean since I checked inside the cylinder and saw slight scoring(more of like a rub)and that the black looking sparkplug is because of a bad ignition system (I'm running around 17 degress timing, I dont know the exact degree) . should I be concerned with the plug and is slight cylinder smear normal? Any thoughts on what I could do to fix it? Any Ideas on what could be the cause of such horrible things? Thank You

Re: Bad Ignition

Probably Fred /

You didn't break it in, you didn't run a temperature gauge and or didn't lower timing till near 14° Or whatever you have to to keep it below 400° Head temps so you smeared/scored some. Your lucky that's all you did.

Many times Kstar kit will bubble the cylinder lining from overheating they're not bulletproof completely .

For no damage ever pretty much to a kit: Time low to start near 14° before top dead center, break in for 300 miles at normal mopeds speeds, and keep it below 400° Head temperature.

The difference between 14° and 17° before top center timing is as much as 75° F head temperatures @ full throttle, slower to get hot and way quicker cool down when you back off.

Re: Bad Ignition

Salsa Valentina /

I've never had the temps close to 400 degrees. I run a temp gauge

Re: Bad Ignition

Salsa Valentina /

Also what would timing it low to 14 degrees help me for? I mean I'm at around 17 degrees and I haven't overheated.

Re: Bad Ignition

Just because the temp gauge says 350deg.at the plug doesn't mean the cyl.wall wasn't over 400 especially where it smeared...lower timing just gives you more insurance at break-in...

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