View Full Version : chain pops off

06-03-2009, 03:33 PM
Chain pops off

i have a problem that dont happen all the time but ti sucks when it does. usually going up a hill climb unless i have it super tight,it have a chain roller about 1/2" abouve chain. and its a o-ring chain.

06-03-2009, 04:09 PM
Hi L-dawg!!

Is it a new chain? If not, it probably has reached the end of its life and needs replacing. The carrier is only able to be turned so far until its time for another chain. If its new, it might be the swingarm isn't tightening up on the bearing carrier properly to keep the chain adjustment in place. The little rubber pieces that you loosen to adjust the chain might be worn out and aren't holding the carrier. Sad thing is, they are discontinued. Honda's way of trying to faze out the rest of the X's. Bass Turds!!! The carrier might be worn too. If so, I would recommend getting an aluminum double row bearing carrier. You can score them from eBay for approx $100. Make sure you get the proper year (85 or 86). There is a difference.

I would also check the sprockets. Also, make sure you have a case saver installed in front of the front sprocket since your chain keeps jumping. You will thank yourself later if you have it on. They only cost approx $14 from the Honda shop.

06-03-2009, 04:30 PM
Ah the case saver! I keep forgetting to get that.

Welcome to the site Luckydog!

06-03-2009, 04:45 PM

If you don't buy one soon, Im going to mail you one!!!


My chain popped off two years ago before rebuilding the rear and let me tell you, if there was no case saver my center case would have been toast. And, I wasn't going fast at all. I was crossing a puddle in 1st gear and it slipped off. The chain got jammed between the sprocket and the case saver. I can't tell you how many times I thanked myself for having the case saver that day.

06-03-2009, 05:14 PM
Yeah, I am going to do it before I ride next time. FOR SURE

06-03-2009, 05:37 PM
thanks for the info, I have brand new sprockets and yes i do have a case saver but i should say that this 350x engine in a 1986 honda trx 250R 4 wheeler frame. And as far as adjusting the chain its 2 12mm bolts you loosen on this and it could still move farther if i need it to but the chain is tight as helll as least to me. does this help any?thanks

06-03-2009, 05:54 PM
Case saver !? I'm going to check on that right now !

06-03-2009, 05:56 PM
Bearing or sprocket alignment ?

06-03-2009, 08:42 PM
maybe im not sure just confuses me that it does it only when hill climbing like hitting the bottom of the hill and go about 10 feet and its off(after the seat compresses down)

06-03-2009, 09:43 PM
Yeah, sounds right. When the most slack on the chain (suspension is bottomed out) it pops off.

06-03-2009, 11:38 PM
how bout the motor swap? Is the swing arm pivot point inthe same relation to the engine sprocket with the 350x as it was with the 250r? Like DOM said when the suspension compresses down this is its loosest point, perhaps the new engine placement has increased this geometry. I would also check on the bearings on both ends of theswing arm like GEOD stated ....This will make it feel like a new bike ...Heck, my 350x rides better than my buds YZF450.....and yes he does spank my tail.......

06-03-2009, 11:57 PM
The extra info helped lots!! Thx.

If you didnt say it derailed after hitting the bottom of the hill I would have went with what Dom suggested.

You might want to look into a chain roller/tensioner. I have one on my 86 X. It keeps your chain tight when the suspension kicks in (decompresses).



06-04-2009, 12:06 AM
Those are some high speed tensioners! Very nice..

06-04-2009, 05:27 PM
yea should i have to have the chain so tight,like no play at all when im not on the bike?

06-04-2009, 08:02 PM
Yo Dog. Give these a look:

06-04-2009, 09:42 PM
the sprockets look to be inline. i dont have any play or noise when riding in the swingarm. But whats the best way to check the bearings? and I got a spec question
about the width for a stock 86 trx250R from outside to outside of the tires is 48" this is just a question i wonder about. thanks everyone for the info.

06-04-2009, 09:44 PM
now the chain roller i have on is brand new i put it on, this didnt have one at all so im not even sure if its right. It looks like is the only place for it.

06-04-2009, 09:47 PM
also i bought or should i say traded for this the way it is. it came with a 350x engine and was suspost to be done by a place called rainbow honda. so not to much i know about ti yet, except that i bought a replacement engine for it cause the other burned oil as fast as you put it in. oh yea i traded a 1995 geo tracker with 169,000 miles in it, not a bad trade....

06-04-2009, 11:44 PM
I have been looking for an extra engine for a couple years now. Hard to find for a good price.

Let's see some pictures of your unit and the new tensioner..

06-05-2009, 07:54 PM
ok give me a doy or two work drafted me to work tomorrow,so as soon as i get a sec. for pics ill out them up.i got this engine from california with shipping it was 568.00 i live in pa

06-05-2009, 10:10 PM
wow what was i smoking when i typed that,lol. a day or two ill take pics as soon as i can.

06-05-2009, 10:32 PM
It's all good man, this is not grammar350x.com!

As long as people understand you, you are communicating well.

06-08-2009, 07:43 PM
yea i guess

06-08-2009, 07:56 PM
You are talking to a guy that spent nine years of his life in Japan. I taught English there for the last two. I would be in front of a classroom of kids spelling shet wrong and speaking poor Japanese all the time. A lot of days I would just tell myself "as long as they understand what I mean I'm doing fine." I worked at two schools and when we had special assemblies I would have to go on the stage and give very short lectures. I would work on them the night before with my wife. Some of the words I would say I had never used before that evening when I was rehearsing my speech. Then I would have my note cards and in front of sometimes upward of 2000 people would talk some shet in a different language. It was a freaking trip dude!

06-09-2009, 05:36 PM
lol sounds like a pain.

06-18-2009, 04:52 PM
i'm working on my uncle's 350X and the chain is uber loose. probably hasn't been tightened since it left the dealership. i have alot of dirtbike-wrenching experience, but i've never tightened the chain on a three(or four) wheeler. help?