I was given a 400L 4x4 basket case and am trying to get it going for hunting season. I have never owned a 4 wheeler before, but am good with engines and vehicles. My 1st problem is that the starter won't turn the engine over. So I tore it apart and rebuilt it. Bench tests great. Still won't turn the motor over. New selenoid. Still not. I replaced the broken pull rope and tried to pull start it. No Go. Won't budge. I pulled the head off to see if it was seized. Cylinder looks fantastic. Measured, not out of round or tapered. I pushed on the top of the piston with a hammer handle and got the piston moving down. Now, it pulls about 2 crank rev. and locks up. I smeared engine building lube on the cylinder walls to ensure lubrication while checking everything else out. I have 2 concerns, 1) the magneto is locking up, and the most obvious 2) bearings are shot, particularly the rod bearing. Is there a common problem with these in the bearing areas? How difficult is it to tear these engines apart?

Thanks in advance!!!!

 

have to wonder if it was run w/ no oil(injection stopped working or didn't use premix) to the bearings and froze up? bearings would be my first guess.

 

If the skirts have broken on the piston, which is very common. don't turn this thing over, what happens is a piece of the skirt gets lodged between the crank and the cases. Then the crank pushes the piece thru the case. Diasassemble the engine and inspect all. Spend 50.00 on a gasket kit to save a whole lot. Doc