250r Craps out....

[CodyJay28]

Went riding for only the second time at the dunes yesterday. Rode for a couple hours then all of a sudden it bogs down and dies...So I try and kick it over and it won't even budge! I've had such horrible luck with this bike...Also sucks because I don't have anywhere to work on it right now, and I just got some shifting forks put it in....which we know is a butt load...I think it's cursed!

[CodyJay28]

Guys got any ideas on what that is, I assume it's my piston, took the spark plug off and there was some super tiny glisten of aluminum

[SWIGIN]

yup sounds like its locked up....it might free up once it cools but its in need of a rebuild

[Liquid-Darkness]

I would pop the top and check her out. If the main bearings and connecting rod seem to rotate freely and correctly, It must be your piston and rings. Inspect the jug bore for scoring or any real damage. If its seased, I would take it to a reputable machine shop and ask them how many over you should bore it to get it back into check. If its a cast piston, 2 1/2 thousanths .0025 clearence. If its forged, then three thousanths is needed .003. Make sure your main jet is rich, like a 160 to start with the break-in. I wouldn't take my main jet any lower then a 145 with any 250R. Should be fine after that.

[CodyJay28]

I was running a 170 in it over at the dunes with a 32:1 ratio...is it pretty easy to do? and how much you think it'll be?

[Preddy05]

that sucks. i had my r do that to me on my way to some local drags. tore it down and found i had big chunk of piston in the bottom end that was locking it up. And the part of piston in the bottom end busted/ cracked the inner cases letting oil in. hope you have better luck than what i did. good luck.

[CodyJay28]

I pray i have better luck than that lol, i just got it fixed and for the price they charged i could have gotten a rebuild one off of ebay....

[Liquid-Darkness]

I was running a 170 in it over at the dunes with a 32:1 ratio...is it pretty easy to do? and how much you think it'll be?


Its not hard at all. It takes a little time and know-how. I am sure these guys here on the board will walk you through the whole thing, once or twice. I am rebuilding my topend right now. I have to wait to get the parts and my ported jug back from Yamahondaman. Its real quick with an R because you can do it while the engine sits in the frame.

piston kit $90
topend gasket kit $25
bore job $70

[CodyJay28]

Sweet, hopefully i can find some time here soon to do it, going to have to find somewhere to work on it...and need a damn job...what'd you have to send your jug in for? and thanks you guys, love this website!

[Liquid-Darkness]

Naw just call around your local mechanics and atv shops or machine shops. Ask them how much to bore out your atv cylinder. Get it miked first to see what bore its on, before you order the piston kit. Yeah this site rocks.

[CodyJay28]

well first of all i gotta tear it apart and see if it is for sure my piston and rings lol

[TeamGeek6]

What part of Oregon are you in? Im in Dry Cities WA and can build that engine blindfolded.

Two things to watch for on that cycle, bad wiring (especially CDI plug) and carb float leaking, both together can torch an engine. Mine has died from a bad CDI plug, and also from the float leaking and flooding the engine. That stock carb is a piece of junk

[SYKO]

and can build that engine blindfolded.



lol awesome!! I love a good ol' 2 stroke for that!! easy as a quadraplegic to bust open!:crazy:

[TJ BIG DAWG]

and can build that engine blindfolded.

Two things to watch for on that cycle, bad wiring (especially CDI plug) and carb float leaking, both together can torch an engine. Mine has died from a bad CDI plug, and also from the float leaking and flooding the engine. That stock carb is a piece of junk

dude what is it with you and leaking floats??? the only problem other that wasting fuel that leaky floats can cause is hyrolock(if you dont know what that is' its when the engine gets a load of liquid being it, gas or water stuck between the piston and head) which can bend or even break the rod.

the problem he has souds to me like an air leak from the way he describes it probably a leak between the clyinder and exhaust pipe connection either that or the intake manifold is cracked and causing a lean condition...the jetting sounds a little fishy as well but you didnt say what year R you have...air or water cooled. were you at full throttle when it happened??? if you need help building your engine drop me a pm...Ive built about a thousand engines......

[CodyJay28]

I was probably crusing in mid 4th gear when it happen, its an 85 atc 250r liquid cooled, located in eugene, or if ya can help me out pm me

[ceaserthethird]

Well before you Start Tearing into your 250R , Check few thing out ....

Check your Reed's , if they are broken your bike will not start

might just want to drop a new plug in and pray you fouled a Spark Plug

if you can't get here to kick over Spray Some SeaFoam inside the Spark plug Hole & Try again ....

Post Some Pictures of the Spark Plug !!!

[Tri-Z Pilot]

It's hard to say what exactly happened till you get in there. I would buy a manual and do the top end myself, it's extremely easy on a two-smoke, even more so if it was air cooled. When you do get the cylinder off, you may be able to read of the top of the piston what size bore you are on now. Never get anything bored without having the piston that is going into it miked (micrometer) first. If you know what piston/bore size you need to go to (I reccomend wiseco pro-lite) order it then take your jug and piston to a good shop and they'll know what to do.
Another thing to do while the jug is off is to check the play on your main bearings, and inspect the cranckcase for anything out of the ordinary, a manual will greatly help with this. You can even get a cd-rom manual off e-bay and other places, and it's only like 5 bucks. Good luck with whatever you decide to do.

[CodyJay28]

There is a bike shop by the dunes where i was, and the machanic told me to take the spark plug and and try to kick it over, it still wouldn't budge. and there was some tiny aluminum pieces on the spark plug, he said it was probably my piston or piston rings. i also mention that the guy who worked on my bike before said the counter balance was getting worn out, so i guess i wont know for sure until i can find a place and time to tear into it...

[CodyJay28]

You guys think i could find a new rebuild top end for about the same price of getting it fixed, like off of ebay, or maybe craigslist?

[TeamGeek6]

dude what is it with you and leaking floats??? the only problem other that wasting fuel that leaky floats can cause is hyrolock(if you dont know what that is' its when the engine gets a load of liquid being it, gas or water stuck between the piston and head) which can bend or even break the rod.
.....

"Whats up" is that I can design that carb, ignition system and most of the vehicle.

How about you?

[ceaserthethird]

TeamGeek6 man i haven't seem you post in a long time ....I think some people got under your never for the Clowning ....

Any who ...

Cody Get a Manual if you don't have one i'll sell you 1 , I have a Honda Service Manual and a Chiltons or something like that ... Send me a PM

[TJ BIG DAWG]

"Whats up" is that I can design that carb, ignition system and most of the vehicle.

How about you?

Im only a certified technition and have been building engines for the last 20 years since I was 10....... so if your so good at it why is it were acting as if his engine was a FOUR STROKE?????????????????? and I think what you mean to say is you can UPGRADE the carb and ignition system as it was already designed by the MANUFACTURER.......with all due respect, please do not try to get into a pissing contest with me as you will LOSE.

[Somekindofjerk]

Building a 2 stroke engine is a bit more tedious than building a four stroke engine. The internal tolerances have to be just about perfect or you will have major problems. Remember a 2 stroke dosnt have crankcase oil to lubricate the piston crank and rod. They use the oil from the Fuel/Oil mix fuel you run.

What probably happened is that the forged piston expanded from heat and bound up in the bore. Get specs from Wiesco directly for piston to wall clearances. Allso ask about RACE applications in which case can require more piston to wall clearance.

After a bore job if you assemble the topend be sure to clean the jug with soap and water then lube it with either pre assembly lube or 10W30 oil. Allso be sure to measure both your bore and piston to be sure on proper sizing!