I just got done reassembling the clutch side of my zilla, had to replace the counter shaft seal and check the timing dots. I reassembled it, started it, it ran for a few seconds, still had the vibration, then died. Now it won't start at all, it back fires and thats it. It has spark(new plug) but doesn't seem to be strong, I checked all my wiring and it seems good. I am gonna have to crack the cases to get the crank checked out for the vibration problem, but would like to get it to start before I tear it down. Is it possible to get the CDI and Coil checked out?I know there are racer and zilla owners that can help me, I know quite a bit about the motor so I not a lost cause.

As far as the vibration problem, what is your input? I lifted up and down on the flywheel and it didn't move so I don't think the bearings are bad, but would it be my best bet to get it checked out?

 

It sound to me like you have an air leak? Also have you checked your reeds? As far as the vibration goes, I am leaning towards the main bearings. Those could be the cause of an air leak and the vibration? How much pressure did you use while pulling on your flywheel. There is a lot of weight and mass in the crank, so I would recommend pulling very hard on it to where your almost lifting that side of the quad off the ground. It's sometimes hard to tell if it is loose while the cylinder is still on? I don't think there could be any problem with the coil if you are still getting spark? You might want to make sure there are no loose wires leaving your stator also?

OutCast
88 LT500RJ

 

A VERY common problem with the Zilla is the timming key shearing then screwing up the timming since the flywheel is improperly positioned. Many guys complain about there quad just stalling for no reason...check the key. The key is there for timming purposes only...the taper is what holds it from turning. Make sure that nut is VERY tight. This is why a flywheel puller is a very usefull investment. I made my own at the machine shop where I work. As for the vibration...you know about the 3 dots not 2. Also do a leakdown test to check for air leaks.

 

I found my problems just by removing the cylinder. The big end of the rod was VERY loose on the crank pin. After rebuilding the crank (new main bearings, hot rod, seals etc..) no more vibration!



Denny

 

I did check the 3 dots on the clutch side. One on the crank, one on the crank gear, and one on the counter balancer gear. Who did u have rebuild your crank truckracer, and how much did it run? I was thinking either sending it off to Tudors Performance or Trinity, also been hearing about Crank Works in arizona.

 

I was going to send my engine off. I had called Trinity and CT Racing. I got cold feet at the last minute about sending the entire powerplant halfway across the country where I couldn't check on it or go get it if need be. So, I mail ordered all the parts, bearings, seals, gasket set, piston kit, sleeve (mine was .120 over !), reeds, hot rod, etc..
I then took all the parts to Brein's ATV's in OKC. He took the crank to a local motorcycle machine shop and they pressed it apart & rebuilt it. I took the cylinder and had it sleeved back to std. bore. I paid $225 labor to Brein's for the labor involved with tearing the engine down and putting it back together. I paid $65.00 for the crank work and $125.00 for the cylinder resleeve. Plus of course the parts that I ordered.
I have been very happy with the results.

I would suggest finding a local independant shop, get to know them, ask around to see what type of work they do, and go for it!

Denny