Merry Christmas all!
My boy recently encountered some of the most common problems associated with these Chinese quads. He's seven and rides the Coolster 125 sport ATV. 6 months ago it was painfully obvious that he's grown out of the Boulder 110 he rode for 2 years. 1) stretched chain 2) broken welds - motor mounts and rear hub brackets 3) cheap Chinese metal though and though and I was expecting this but as a result he threw his chain numerous times and the final time ended up in the crank case, cracking it. It even sent a piece of metal into the stator and bounced around just long enough to sever a couple vital wire welds. I was running Royal purple 10-40 oil in it and I'm pretty sure it burned up my 3 gear clutch plates because when I pulled the drain plug out, i literally had to stick a small screwdriver in the drain to start the, what is now molasses, oil to come out. My biggest concern is that just above the drive sprocket there's a couple of wires coming out of a rubber bushing and held on by a phillips screw and a cheap metal bracket. What is this? I pulled the the screw out, removed the bushing and had no idea of what I was looking at so I put it back together.
FYI- I ordered a new complete engine instead of trouble shooting all the other problems and dropped it in yesterday... new RK chain, 12t drive sprocket, new adjustable carb, new fuel line and K&N filter, Honda 2 1/2 inch rear wheel spacers, gas piggy back shocks and LOTS of locktite.

Can anyone tell me what that little rubber bushing with wires above the drive sprocket is and does? and why we're at it why do some of the vent hoses from the crank case go to the air filter and some don't? I modified the new engine to filter through the air filter.

Thanks in advance!

 

By the way, about my last post... The vibration was caused by an incorrect spark plug gap.

 

I never would have guessed that one.

 

Yep... the gap was way too small and the spark wouldn't ignite the fuel efficiently.

 

The piece you're talking about with the wires is the gear indicator switch. Crankcase vent doesn't have to go to the air filter but it does reduce air pollution.

Changing the oil before it becomes too thick to drain will make the engine last a lot longer.

 

AHHHH!... Gear indicator switch - that would tell the neutral light and the reverse light when to come on. GOT IT! Thank you