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View Full Version : Original piston 250R locks up, now what?



Blown 331
11-25-2004, 03:25 PM
1985 ATC250R
Yep, I've had it for about 6 weeks now, just got my ESR exhaust on it a few days ago and it's locked up. I was riding down the road, probably about 50mph and I heard some weird noise so I pulled the clutch and it died. I coasted to a stop and it wouldn't kick. There was also a small about of antifreeze around the head gasket.
I pulled the cylinder and both piston skirts are broken off. The crank appears to be ok but wont rotate from the piston in the lower end. I pulled the entire motor and am in the process of splitting the case.

Now for the big question. What should I do now? I have a TRX450R and I want the 250R to smoke it. I want to spend about $600 to $900 on the motor, so that doesn't cound a new carb, I may be able to stretch that a little.
The crank will be out so I don't know if I should stroke it while I'm there or what. What about a long rod and spacer plate? I also don't know if I should just get a .020 over Wiesco or just get a big bore cylinder. Or maybe look for a whole built motor on ebay.

I need some suggestions here, I'm kinda new to 250R's. Any one have anything for sale? I can go higher that $900 if it's really gonna run.

Blown 331
11-25-2004, 05:24 PM
I was checking ebay and power valve motor are going for a decent price. Think I should just buy one? There is also a 5mm ESR stroker crank on there. Any pros and cons to that? What do I all need to use to use that crank? Can I used just any Weisco?

Tom TRX250R
11-26-2004, 12:16 AM
Honestly man that stock ATC should beat the 450R's ***!!! Believe me I have stomped tons of quads with my buddy's stock 86 ATC250R with only a pipe!! The only thing that will beat it is complete drag banshees otherwise you should be fine!!! About the Powervalve motors I suggest going with the ESR 310 kit (bolt on.) It will give you more low end grunt but if all you want it for is dragging then you will be better off going with a non powervalve motor. All of the drag racers I have talked to about racing with 250R motor go with the non powervalve motor. I recently rebuilt my 86 TRX motor from bottom up and put an 89 long rod with spacer plate which gives you more low end torque and ported/polished cylinder, ESR TRX6 pipe, 38MM Airstryker carb, V-force Reed cage, and it rips *** now!!! That be my first suggestion would be to port the cylinder, put the long rod in it, with the spacer plate, and buy either the ESR TRX5 or 6 pipe! And after that it is all about how much money you want to spend including big bore motor, etc. etc. Good luck man!!!!

Blown 331
11-26-2004, 05:26 AM
Well I want the ATC to beat the 450R but it isn't even close. My buddy has a built TRX250R and the 450R smokes that too. (he has a 450R also). My ATC has an ESR ATC-5 pipe on it, has about 30 minutes of ride time on it. I'm gonna call ESR today and see what they have to say. I think I'm probably gonna take my chances and buy a motor off ebay, they seem very reasonable.

Pvt. Maggot
11-26-2004, 08:51 AM
get a cr500 motor in that beast and git r dun :devil:

Blown 331
11-26-2004, 08:55 AM
Originally posted by Pvt. Maggot
get a cr500 motor in that beast and git r dun :devil:

I really thought about doing that. My 3-wheeler is super nice and all original so I don't want to hack it up too bad. lol. I don't like the idea of taking the fenders off to kick start it either.

Roostin250R
11-26-2004, 08:57 AM
I'd be very careful buying off ebay, you may wind up with more headaches than its worth. At least if you rebuild YOUR motor, you'll know what you really have. I would follow Toms advice, my motor set up is similar to his with the exception that mine is an 89 motor, and it will hand the 450R its *** in a race with both riders being experienced riders. No doubt the 450R is a fast machine, but for the money you want to spend on mods, you should be able to make that thing RIP!

Blown 331
11-26-2004, 09:07 AM
I hear ya about buy an ebay motor. I found this one and the seller is a member of exriders.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4506397124&rd=1&sspagename=STRK%3AMEWA%3AIT

I don't think I can build anything like this for the price. I'm gonna see what ESR has to say. I want this thing to be fast! Should run good considering the 3-wheeler weighs under 300 pounds.

wilkin250r
11-26-2004, 06:13 PM
Me personally, I've bought several motors off ebay, and I have never been satisfied with any of them. You might have better luck than me. I would also be very wary of cranks off ebay.

If you end up rebuilding your own motor, it's obviously going to take several hundred dollars just fixing whatever is wrong now. Beyond that, I would suggest some good port work and head mods (or aftermarket head) to compliment the pipe. At only 300lbs, a good port job should make that ATC untouchable in a drag race.

sdxp787
11-26-2004, 09:28 PM
In my opinion, you should rebuild your own engine. That way, you know what you have when you are done. The ATC should give the 450R a hard time due to the weight advantage of the ATC. Another thing, LA Sleeve can put a 295 sleeve in your existing cylinder. It isn't very expensive, about $500.00. I have a few buddies who have this done on their TRX's and they scoot on down the trail. What you do is up to you. Every one of these suggestions are great, but what makes you comfortable in the end is really what matters.

jcas
11-29-2004, 10:49 PM
Check your crank seals!!!! I had just completed restoring an 83R and the first day I took it out the piston seized. No sweat, I wanted to rebuild the top end anyway. Had it bored to 265 with a weisco piston and rings. Started on the first kick and began the break in process. FIRST time I took it out, it seized again!! Turns out the crank seal on the flywheel side is letting air in. New parts coming in and the process begins again. Good luck!

87R
83R
81 200