205sx Engine died

[cybrman]

I went to go start my 250sx yesterday and it started to turn over and then halted. It sounded like something got hung up, and I was thinking boy I'm glad whatever gave way did so upon start up instead of at 3k rpm or something.
I loosened up the valve cover and then the motor was able to turn again. I just moved it with the kickstart and no way was I gonna try and start her up.
So now I'm looking at my cam shaft and timing chain and there is a considerable amount of play. I looked at the adjuster and I am not sure how it functions, but removing it was all I needed to slip the chain off the cam sprocket.
Haven't gone any further as I'm not sure what I'm looking for, but my guess is the chain is stretched out and sloppy. The bike was making some valve like clicking noises which I could never resolve by adjusting the valves they seemed fine.

Can anyone give me some insight into how loose is too loose for the chain? Before removing the adjuster it was loose enough for me to almost get it off the sprocket.

[ScottZJ]

It shouldnt be that loose, but you should have had a nice tapping sound if it were loose prior to this time. It should almost sound like the valves tapping but louder. The adjuster on these motors are "automatic" so to speak. So if it is indeed really loose, might be best to replace the chain. I bought one on egay for 25$ for a new one. I know its not OEM but its new and a chain.:) .

http://cgi.ebay.com/ebaymotors/HONDA-CB400-T-CM400-CB450SC-ATC250-TRX250-CAM-CHAIN_W0QQitemZ380063135860QQihZ025QQcategoryZ3559 5QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[cybrman]

Thanks Scott.
It was indeed making some noise and I could not figure out what it was.
Hyperparts has the chain for like $70, probably just get that and be sure I got something new. Ebay has not been kind to me in the past.
Although after looking at it maybe I'll give it a shot for $25. You say you have purchased this same one before?

[userj8670]

Sorry to hear about the SX my friend. Mine is due for a rebuild at some point as i am sure its a ticking time bomb. I looked at your pics of the sx's and the one has some enormous tires on it. What exactly are they, they look pretty sweet. Do they fit on the stock rim?



Thanks and good luck!!
Jim

[ScottZJ]

Yes I got this same exact chain from the same dude. They are really fast in shipping and no probs. It looks just like the stock one to a T. I havent installed mine yet but will do it soon.

[cybrman]

I looked at your pics of the sx's and the one has some enormous tires on it. What exactly are they, they look pretty sweet. Do they fit on the stock rim?

The tires are called maxxis mud bug and they came with the bike 25x12-9. I love em, though I haven't had the chance to put them to real use yet they kick ass in the backyard and have made some good ruts around my boat lol...Got a lil circle track we ride around the backyard...love to get the 70 out and its like at the go cart track, wide open kick the back out in the turn and right back on the gas....wife gets nervous as I almost impaled myself on the tongue of the boat trailer once, but that was with the 250sx....the 70's harmless :naughty:

Anyway Scott one more question about the chain...the question actually.... how loose or how tight should the chain be...
If this was my drive chain on a 200s for example I would think it was too tight or maybe just right with a lil slop. In this case I'm thinking this chain should be nice and tight without any play, but I am not sure. I want to be sure its really the problem...

[ScottZJ]

Well if you didnt hear alot of engine chatter before the trike stopped, then I almost doubt it is the problem. As most chains when loose make some serious noise and you know something is wrong. It sounds like to me your piston was stuck due to gum up and it broke loose. I would spray oil down around it and maunally move it up and down. Then put together and hit the starter once and see if you hear the noise.

[cybrman]

Update....
Well I finally got around to pulling the head off this weekend and voila there is one of the valves sitting on top of the piston.
Piston and cylinder look fine and I'm thankful I didn't mess with it more before tearing her down.
I ordered the intake and exhaust valves and some new rings from hyperparts last night.
In talking with my brother who is a Ford mechanic he seems to think the chain adjuster is bad as well. Anybody know where I can pick up a new one of those?