Help me out guys and gals. I have a 95 zrt800.
The second last ride of last season I blew a piston. I was able to just hone the jug and replace the piston, rings, clips and bearings. When we were putting the antifreeze back in we tipped the sled on its side to help get the air bubbles out (I had very little oil in the oil tank). I then filled the oil tank and ran my gas/oil 50:1 for the break in period of the new piston. We put on about 100 miles and then had a fill up. Things were going great. We partied most of the night so when I got up in the morning things were quite fuzzy. We got the sleds warmed up and took off. Halfway home my sled died and I got towed home. :cussing: When we took the heads off another piston popped :hallo3: and that's when I noticed that I used no oil for the outing. This time the jug was beyond honing. So I called it quits for the remainder of the season, until I could afford to get another jug. In the mean time my family got together, chipped in a bunch of cash and bought me a complete motor from another 95 zrt800 (with half the milage of mine) that was written off (all cosmetic damage) for my birthday/christmas present. The friend of mine that picked it up new the sled and the motor so he knows its good to go. Anybody that has ridden my sled can't believe how smooth it is for a 95. There is no vibrating to speak of, so I'm thinking my crank must be ok. Now this is where the problem comes in. I have a friend that says do the wholesale change and keep the my original motor as parts or get another jug and have a second motor. I have two other friends that say swap top ends and go. I'm leaning towards the latter of the two suggestions. With the second motor I have an extra oiler that does work so if I find out mine is shot I can replace it.
What should I do, I can do the top end swap by myself in a couple of hours (I'm not speediest mechanic), but I wouldn't know where to begin to swap motors. SWRules

If you have no reason to suspect any problems with the new engine, then I myself would do a complete swap. Probably rebuild the old one when you have time.
Depending on your mileage, its probably time for new crank bearings anyway.

Its not that big of a job to do a swap out. start this weekend, and you will have lots of time before the snow files.

FishHog

I'd do a complete engine swap. If you know the engine is good to go then why mess with it? It would cost you money in gaskets.

The motor swap is quite easy. Personally I'd rather swap motors than do a top-end. It's harder to screw up a motor swap.

I echo the complete motor swap recommendation. If the oil pump was a problem on the old motor it may have caused a problem with the water pump and you could get leaking into the balancer shaft bearings. I have always heard that it is imperative to watch for any coolant coming out of the water pump weep hole because it can take out he balance shaft bearings very quickly. If they go you will need a new crankcase and a lot of other expensive pieces.

I too say the total motor swap and work on the second motor as time and money are available. To be honest I think a total motor swap might be easier to do then go thru the entire engine and check out everything.

Thanks,

Tony

Wow, sounds like my story. After replacing my motor recently, I look back and ponder my crank failiar and think my mistake was changing the piston and not cleaning out the base of debris.

Motor swap is the way to go.

I had this same story a few years back and I did the top end switch. BIG mistake I should have replaced the whole motor and rebuilt my origional for a backup. When I got the thing running with the new top end after all the time and money for the gaskets and stuff it blew after 150 miles. When I tore the whole thing back apart I found a crank seal that was letting air in past the crank and leaning the motor out at high RPM. ANYWAY if I had to do it again I would have done the entire swap and taken the origional motor out and completely rebuilt it for a backup. Yes it is easier to swap the top end since you have to have a clutch puller and some other tools to do the entire swap but I would rather be riding when the snow fly's instead of looking at a broke sled and a empty wallet...