Hey Folks,
I’ve been beating my head against the wall for some time now on this. My sons ATV is struggling to spin fast enough with the starter to start. I used to use a booster pack and it seemed better but I eventually burnt the brush plate out of the starter as it got so hot I couldn’t touch it. I’ve replaced the battery, installed a new starter and solenoid and even tried a car battery. I replaced the starter wiring with heavier gauge from starter to solenoid, solenoid to battery and ran a new ground wire from battery to engine block along with adding a separate ground from block to starter casing.

I found another thread here that said the starter clutch can cause issues where the “barrels”
can become dislodged and jam things up. I was happy to take this one apart and find a barrel not where it should be. I put it all back together correctly and was excited to see it spin but ended up no farther ahead.

I’ve attached a video showing the problem. Any input would be greatly appreciated.

Darren

 

After posting this thread, I read through a couple more things and found a couple other steps. I went out to the quad, took the spark plug out and was able to spon the engine quite freely by hand. I used the starter to crank the engine over without the spark plug in, it spun like it was going to go into orbit. As soon as I put the spark plug back in I’m right back to where I was

 

fix your exhaust valve. what your describing says you have good compression the problem is your topend is out of spec. figure out what your valve clearances need to be and adjust them check your cam too while its all apart.