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By Susan Makowski-DeGraw
My quad runs, it starts up runs for about 10 minutes and then it dies if you let it sit for 10 minutes it’ll start back up ride for another 10 minutes and then die again, trying to figure out why it keeps stalling
Following on from the brief interlude in the "introducing myself" thread....
In a nutshell, I acquired a YFM250 Moto 4 (1991) for cheap recently with the previous owner citing "no spark, needs a new magneto coil and I don't have time to fix it"... anyway I am dubious that the magneto/generator is the issue and thinking more along the line of ignition coil as after a clean up of the magneto I was able to get a rather decent voltage reading off the magneto with pull start and resistence readings seem to check out that the magneto is all ok (all 3 x phases = 1.2 ohms and no run to ground)
None the less I ordered a new Ignition coil and Magneto/generator coil and am waiting for them to arrive.
In the mean time I cleaned up the current Magneto, popped in a new battery and sparkplug, checked out all the wiring harness, all seemed good except I came across the "neutral switch" wire was broken.
After wiring up a new neutral switch wire, the neutral light now comes on (small win) and the starter relay (attached to rectifier) now clicks. If I hit the starter switch on handle bar the starter motor spins and if I pull the cord starter I get a spark on pull....YAY!! I'll try and attach a video below if possible.
So onto the starter motor. Starter solenoid seems to work A-ok, even if it looks crappy and starter motor spins as it should when I hit the start switch....but here is my issue.
When the starter motor runs it turns Cog #1 and Cog #2 (see photo below)....but the chain in the back of the starter which I assume is the timing chain, does not move and there is no apparent movement of the piston in the cylinder.
If I turn it by hand (per photo) or with the pull starter however the chain moves and the engine turns. However cog #2 rotates but not fluidly with the "Crank" (part I turn by hand) for the lack of a better word to use if that makes sense?
Is there a grub screw or similar on Cog #2 that fixes it to the center shaft to make it all turn when the starter motor is run? Could there be a part missing? Previous owner had the starter apart so could be possible?
The outer/front part seems to be on a key-way so not sure how to remove this easily to check how Cog #2 is attached.
What am I missing here?
Hey so i have a 1990 bayou 220, and its missing the wiring harness so i went online and bought a bayou 300 wiring harness by mistake. Will it work if i use the 220’s cdi box and ignition coil?
in this thread, I want to discuss how 4-cycle atv engines work- what the different types are... how they are set up and which you prefer. To start off, are the cams on ALL atv 4-strokes powered by a cam chain? I know that on say a lawn mower or logsplitter engine, the cam is turned by the tappet, pushrods, and valve rockers. Which is better and why? Chain-driven cams or pushrod-driven cams? Are the pushrods just an old version and everything is transforming to chains or the other way around...or not at all? Just looking for some explanation, history, and downsides/upsides...
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