About 8 months ago, I bought a new red TRX250EX for my son to ride... Back in March, we was riding in the mud and
the motor siezed up on him. Took to the Honda dealer and the crankshaft spun a bearing, siting the cause of the problem
was improper maintenance. No Warranty coverage beyond 6 months and I am having to deal with a major rebuild of
a new atv. They said I failed to change my oil... but there was sufficient oil in the crankcase and it was still brown.
THe ATV probably has a total of 30 hours on it and my oil was still brown.

OK, so I take this motor apart... takes me weeks to get the crankcase split apart. This long wait was due to the fact
that *nobody* could pull the flywheel off. The local honda dealer had to order a special puller. They said they never
had one of these models go down on them, and they didnt have the puller. Finally, I get the flywheel off after waiting
3 weeks.. and when I get the engine home, I see that the deal had dinged my flywheel with a hammer. Of course
they wont acknowledge they did the damage, but here I am with yet another expense. I dont know if the ding is
repairable or not, but I am still pi$$ed about that one.

So I press out the crank from the cases and inspect... sure enough a spun pushrod bearing laying in the bottom
of the motor, all twisted up and the crank was blackened from the heat/friction. The consolation was that the crank
itself was only $99 (relatively cheap compared to other cranks).

Now the motor is being reassembled... ReInstalling the tranmission is really tricky business, becuase you have to
handle the entire assembly in your hands and negotiate it back into the crankcase. It was really tough and took
about an hour before I got it back in.

The gaskets in the motor (green) seem to be glued in, because you cant remove them. I have been working at
1 gasket for better than an hour with not much progress. I soaked them in varsol (mineral spirits) and scraped
them with a putty knife and I get maybe a mm on each scrape. I decided to spend $100 on new gaskets upper
and lower, but I dont know if I'll ever get em off. I should have just left the gaskets alone, cause the sure
aint going nowhere and their probably just fine.

So when I get this engine back together, who knows if it will run again. I sort of questioned the side-ways
motors on these things and now I know first hand just what thats about. They crapola and you can bet as soon
as I get it going, this quad will have a forSale sign on the side of it ASAP. I would have parted this puppy out,
but I still owe money on it, so I need to get it going again.

If anyone out there has a 250EX flywheel for sale, please pm me. Also, if anyone wants to share info about the
250EX... I know it like the back of my hand, inside and out.

Regards,

 

It's a little late but I think that you should have written Honda before doing anything yourself. Then I would have taken it for a second opinion. Sometimes you'll have better luck with another dealer contacting Honda. I had a problem because of dealer error and when I took it to another dealer they got Honda to cover the problem even though the warranty was up. Did the dealer have someone from Honda come out to look at the problem? If not, they probably should have.

 

i bought a honda 250ex 03 about 4weeks ago, do you think i should just get rid of it???? why did the engine sieze up?? [img]i/expressions/face-icon-small-frown.gif[/img]

 

How do you spin a caged roller bearing? That is what is on the bottom of the crank. What else melted down?

Piston?
Rocker arms?
Cam?

 

nah it wasnt a roller bearing, it was a pushrod bearing... like a large flat washer on the side of the
pushrod on the crank itself... No idea why it fried... At the time, the crankcase oil was a little low, but
definitely showing on the dipstick within the fill tolerance.

hayve, I really dont know bro... All I can tell ya is my personal experience, and it was a
bad one. IMHO, the machine is a little underpowered, but I bought it cause it had reverse and
since my son was the primary rider, that is best... cause I dont wanna be pushin his a$$ out
of the mudhole.

I dunno if its the engine design or what, but I learned my lesson. On the other hand, I am
a huge fan of Honda, and I have been riding a 1994 Honda TRX300EX for the past 9 years with
no problems whatsoever. The engine on the 300EX is tried and true.

My son rides hard for a 10 year old, but even, so I feel like the engine crank might have been
defective. Another thing I noticed... While I have the crankcase split apart, I noticed some
hairline fractures of the case itself... the cracks dont go all the way thru the casting, but it
doesnt look good. There is no way these fractures came from anything we did, because the
cracks appear underneath the motor and protected by the frame. It appears to be a manufacture
defect and sort of makes me suspicious about the QA process.

Well... My gaskets came in today, so I gotta start getting this motor back together.

caio,

 

wow. i can honestly say i have NEVER heard of any case like that. i have roughly 40 hours or so on my '02 250 and i have had no problems. bought it in november of '01, installed some mods last june, and have ridden hard on it ever since. and no problems.

not saying that this is the cause for this, but you probably should have changed your oil sooner. i remember i changed my oil as soon as i hit 15 hours (even though i meant to do it at 10 hours) and changed it again at 35 hours.maybe i could go longer on my oil before changing it, but the way i see it, it never hurts to do some preventative maintenance.

i also have most of my more advanced maintenance done by a atv mechanic who is also a engine builder on the side. i do this instead of going to a honda dealer because personally i do not trust the dealers in my area. i now have a service manual, so i will start doing most of my own work in the near future.

i'm not all that familiar with the internals of this motor, but it does sound defective. i have heard many 250EX owners talk about how this machine NEVER lets them down. i am one of them.

good luck trying to get it to run and sell it. the EX is a reliable little machine (under normal circumstances) and i think this was just a freak thing.

 

You can hardly say the sideways honda motors are crapola, there are TONS of recon's, 250EX's, Foremans's, and Rancher's out there with absolutly NO problems, you just found the one in a million lemon....sorry to here about it but it was just a fluke....

 

As a longtime career technician I can tell you that's about the easiest engine Honda ever made to work on. You should try an old v-4 engine sometime. The marks you see on the cases and covers are probably casting marks, you can find them on just about any Honda engine. Sometimes they look alot like cracks.

 

I do sympathize with you on the gaskets. Those green ones can be a real bugger. buy some cheap safety razors for those, but careful, don't cut yourself.