Engine not starting, ran it with an exhaust leak

BikerRay

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Hello.

I had some problems with my engine a while ago but it turned out to be a fuel problem. Can read about it here, but not that important right now I believe: https://motoredbikes.com/threads/engine-started-before-but-not-anymore.66112/

6 months ago I ran it about 25km with a leaking exhaust. At first, the engine ran fine. I tried fixing the leak and eventually gave up. The further I rode the more the engine started dying. Eventually, it did not idle anymore and then it did not start. I tried starting it, it just "started to start" (so fired a bit) but did not start. I left the bike there and got it delivered to where it is now. 6 months later I fixed the leak (before I could not tighten the exhaust fully because the threads were stripped and that caused it to leak), but the engine is not starting. Does not even start to fire when I pedal it around.

I have spark (can see it visually in the dark and the RPM gauge, which works by reading sparks, shows RPMs.
I believe I have fuel going to the cylinder because if I try the cylinder with a paper towel, put the thing back together, and crank it - then it gets wet again.
I have compression.
I tried changing the fuel for a new one and even tried putting a bit of fuel into the cylinder but that did not help it either. (the pictures are taken before I put something in it manually). The amount I put in it just made the piston head a bit wet, but did not make a puddle in it as shown in one of the pictures.


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In that thread, you never stated there was a resolution. What did you find to be the issue?

Did you end up replacing the kit plug with an NGK one?
There have been MULTIPLE instances where someone "has a spark, there is fuel on the spark plug", etc., but "it just won't run", and the issue has turned out to be the cheap kit plug. IF YOU HAVEN'T, REPLACE IT. They can very well spark when you check it, but not under the compression of actual running conditions.
 
At least I believe the fuel was bad because it sat in the tank for a long time and turned yellow.

About 20:1 but I want to make it leaner in the future. Apparently it should be much leaner.
 
Here's an idea, get yourself a sheet of 150 or 120 grit sandpaper, and a sheet of glass. Tape the corners of the sandpaper down on the glass, flip your cylinder over and sand off those lines on top. Then do the same thing with the head. Wash them both in warm water and dish soap, then reassemble with a new gasket.

Now for the exhaust side, get a O2 sensor gasket, ask politely someone will let you know which one, and put your muffler back on and double nut the studs.
 
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