Anyone hear of this or had it happen? I had the valves done by the local Honda shop recently and after I got it back the nephew rode it for 4 or 5 hours and the part broke (part #14102-KRN-670). Opened it up, found the half that broke off and replaced. Rode again for a few hours and again the part has broken. 3 parts in about 10 hours. Obviously there is something more wrong than meets the eye. Could the shop have put something together wrong to cause this? I'm totally at my wits end as I know each time I throw $20 at it to fix I will only have a few hours time before it breaks again, and possibly worse (getting the part in the valve).

Anyone???

Thanks
John

I haven't heard of this, but maybe I'm not picturing it clearly.......any chance you can post a picture of the head so we can see what you are??

quote:

Originally posted by DeVol911:
I haven't heard of this, but maybe I'm not picturing it clearly.......any chance you can post a picture of the head so we can see what you are??

It's part number 4 that breaks in half. It's like the decomp arm pushes it out.
It's actually only been twice now, I took the cover off and this time it's not broken, just making a loud clicking noise in there. I have heard that these are kind of noisy on the top end.

http://www.motosport.com/dirtb...ar=2004&groupId=2716

Thanks Devol911

shouldn't be too loud. at idle that arm can kinda "clack" around, but if it's excessively loud your valves may be too loose. still a wierd problem with that plate, the weight (#3) isn't damaged at the point where it hits the roller? maybe that would both cause the noise and push it out, breaking the plate?

I've broken this tab in an '07.
Decomp shaft makes quite a racket as it slides out. I assumed it fatiqued and failed.
If the little tab in the center is not lined up with the corresponding hole in the cam, it might bend and then break. If you're missing any pieces from this tab, they're in the magneto.

quote:

Originally posted by Mikey350D:
I've broken this tab in an '07.
Decomp shaft makes quite a racket as it slides out. I assumed it fatiqued and failed.
If the little tab in the center is not lined up with the corresponding hole in the cam, it might bend and then break. If you're missing any pieces from this tab, they're in the magneto.

Clacking at idle yes, clacking when above idle, yes. First break was back from getting the valves done at the Honda shop. Only put about 5 or so hours on it. It's the bike I bought my nephew so not sure how long he rode with it broken. Opened it up and replaced, didn't check the valves since they were just done. There does not appear to be any damage to anything up there. Cam is tight with no play and valves appear to be fine.
Found the tab sitting right under the mag just like you mentioned both times.

check #6 the exhaust valve pusher cam follower whatever you want to call it. Check the roller bearing on top the cam contacts. If the engine was ever starved for oil this bearing does fail and makes a loud noise that sounds like loose valves and a decomp failure. I've seen this happen on 1 250 and 1 450.

quote:

Originally posted by DeVol911:
check #6 the exhaust valve pusher cam follower whatever you want to call it. Check the roller bearing on top the cam contacts. If the engine was ever starved for oil this bearing does fail and makes a loud noise that sounds like loose valves and a decomp failure. I've seen this happen on 1 250 and 1 450.

Never starved of oil, however I mean it's never been low on oil. I'll check again, but first go around everything looked and felt tight.

Thanks Devol911!!
Here I thought I was only buying myself a new 450, might just be a 250 as well

Well.....it's an 04' could just be time. Hard to say, but the two I worked on definately had been low and the 250 actually they admitted they ran it without oil. Just something to check. The decomp was our first thought too, but after a decomp didn't fix it we found that bearing while rechecking everything. This is one of those times where you wish something was available that would allow you to run the bike with the head cover off and just watch and listen to whats going on.

quote:

Originally posted by DeVol911:
Well.....it's an 04' could just be time. Hard to say, but the two I worked on definately had been low and the 250 actually they admitted they ran it without oil. Just something to check. The decomp was our first thought too, but after a decomp didn't fix it we found that bearing while rechecking everything. This is one of those times where you wish something was available that would allow you to run the bike with the head cover off and just watch and listen to whats going on.

Some type of see through plastic head cover would be nice. Not sure you could see through all the oil though.

Probably is time....

Thanks for the thoughts and info Devol.

quote:

Originally posted by Mull#13:

quote:

Originally posted by DeVol911:
Well.....it's an 04' could just be time. Hard to say, but the two I worked on definately had been low and the 250 actually they admitted they ran it without oil. Just something to check. The decomp was our first thought too, but after a decomp didn't fix it we found that bearing while rechecking everything. This is one of those times where you wish something was available that would allow you to run the bike with the head cover off and just watch and listen to whats going on.

Some type of see through plastic head cover would be nice. Not sure you could see through all the oil though.

Probably is time....

Thanks for the thoughts and info Devol.

So looked it over and then looked it over again and nothing looked out of place and nothing seems to be loose or have play. Kid rode it for a lap at Agassiz last weekend and it quite. Sounds like exhaust valves as it won't start and backfires/pops when you try.
Maybe just shims?? I just put new valves in it maybe 10-15 hours ago.

Anyone do them?