At The Back Of The Pack
Arm chair racerAt the back of the pack
I'm buying this top end from a feller and he said that they put the wrong valve in it. He said that they put a "atc" valve in it, and it's an xr200. Little does he know, they all use the same valve. It obviously did have problems though. Any thoughts? I don't see how this could be. Unless the valve was bent maybe? You can see where the valve touched way higher on the piston that it should have.
If what's shown is the only damage, should still be good to go correct?
Thanks for any thoughts.
-Fathers 1985 200X
Power User
The day begins with 3WW
Someone else sure knows more but:
a) could be old damage and has nothing to do with the new valve
b) should be polished down since sharp edges are known
to cause preignition when they glow
Did it ever run?
or sounds like it blew up, valve got replaced with the "wrong'
one and never reassembled???
At The Back Of The Pack
Arm chair racerFirst time rider
So your just gonna use the jug and the piston? you are assuming that this will work on your trike i take it? If I were you I wouldn't mess around with buying used crap like this. Bore out your own cylinder and get a piston kit for your engine....then you'll be "good to go"
I'm like an Original Gangsta...but a post whore instead.
The day begins with 3WW
Looks like it got bent with a previous head on it...then the was fixed...piston left in after problem...maybe?
My old 1985 250R http://www.flickr.com/photos/24898661@N07/show/
Feedback http://www.3wheelerworldforums.com/s...feed+back+edog
Currently trikeless
At The Back Of The Pack
Arm chair racerFirst time rider
A bit of surface indentation on the piston crown shouldn't be a bother in itself - agreed it would be best to smooth off any sharp edges.
This looks a bit like someone tried to turn the engine over with the valve timing totally wrong. The first contact with the valve may have bent it a bit and then the second contact was a bit further across. The engine could never have run if the valve was like that so I should think the piston is okay. The marks are well away from the edges so the ring grooves should be fine. Check the rings slide in to their grooves check the ring gaps are within spec.
Check the clearance between the piston skirt and the bore at the top, middle and bottom of the stroke and check front and back and side to side - this shows if there's any taper or ovality in the bore and if the piston is a good fit. Compare with the specs in the manual. Check the piston and bore haves no heavy scuffing marks (machining rings should all be visible) and the wrist pin bearing is not sloppy. Might want to clean the gasket face up a bit to make sure it seals.
Bill
Custodian of:-
85 Tri Z - need rear plastics to go with Mosh seat cover
83 200x - engine being rebuilt but lodging with a friend
85 250r - also lodging with a friend until I have a new shed
....and a different kind of Z
At The Back Of The Pack
Arm chair racerAt the back of the pack
This cylinder and piston is brand new. From the bore and hone to the piston itself. Which is why i am buying it. I have the tools needed to polish the sharp edge's down and that will not be an issue. I think that it was off time as well. I most definatly will not pass this up. Even if the cylinder and piston won't work.. don't know why it wouldnt.. i will still have a head, cam, and carb out of a xr200 for A HUNDRED bucks. Which is a really good deal to me.
-Fathers 1985 200X
I'm like an Original Gangsta...but a post whore instead.
The day begins with 3WW
Or the piston was installed backwards.....sound like a good deal to me!!Originally Posted by kasey200x
My old 1985 250R http://www.flickr.com/photos/24898661@N07/show/
Feedback http://www.3wheelerworldforums.com/s...feed+back+edog
Currently trikeless
Power User
Lord of the trike
How is the piston new if it already has a valve ding in it?
Rob
At The Back Of The Pack
Arm chair racerFirst time rider
Post some pics of the piston skirt and the bore if you can - it'll be easy to see if it's worn or picked up. Piston top looks new and at the very most, you only need to use some emery paper on the sharp edges of the dings, don't need to erase them. Sure, they'll fill with a little carbon over time but it won't matter at all.
Custodian of:-
85 Tri Z - need rear plastics to go with Mosh seat cover
83 200x - engine being rebuilt but lodging with a friend
85 250r - also lodging with a friend until I have a new shed
....and a different kind of Z
At The Back Of The Pack
Arm chair racerAt the back of the pack
That was something i also thought!
-Fathers 1985 200X
At The Back Of The Pack
Arm chair racerAt the back of the pack
You right, pardon my bad wording. It was "fresh."
He Say's it had 10 hours on it and ran great. So I'm left to believe his cam chain jumped time and caused that problem. Sound agreeable?
-Fathers 1985 200X
At The Back Of The Pack
Arm chair racerAt the back of the pack
Here is a few more photo's. The head looks really nice, aside from the paint. Which will be redone. Hopefully the valve wasn't bent.
-Fathers 1985 200X
Got The Holeshot
Arm chair racerJust too addicted
Those marks just didn't happen from turning the motor over.
If the valve was making contact with the piston because of mistiming of the cam it wouldn't have turned over by hand with the spark plug out in the first place.
Also, those marks are in slightly different places on the piston dome. Seems to me the marks should all be in the same place.
Have '85 350X-XR500 Hybrid,
Had Nicholson framed: 90/110, 185s, Gen I 500, Gen II 500
Had Bandito Framed 90
Have Vey's Framed 90
Have too many parts
Power User
The day begins with 3WW
i think the piston is in backwards. i think the intake port is on the wrong side. that or it;'s the wrong piston all together. if the valve touches the piston it bends the valve. so you will have to replace it. the only other thing I can think of si they did not proeprly aling up the timming marks on crank and then on the cam. that is a common issue as well if your like 2-3 links out.
I would not trust he was honest about the engine starting. I think he attempted to start it and found out he did something wrong. then it also looks as if they did not use oil to put it together and then tried to start it w/o using any oil and even with the plug in.
I would at this point not trust anything they told you. take it appart do it right and start fresh.
Last edited by oscarmayer; 01-14-2011 at 04:44 PM.
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At The Back Of The Pack
Arm chair racerAt the back of the pack
Maybe it jumped once, then when the valve hit the piston it caused it jump more and more, Until it just stopped. That would cause this to happen correct?
And oscar, like i said, even if the cylinder and piston do not function correctly, i'm still getting alot of other stuff that is going to be included. So either way, i may get real lucky, or get off just satisfied.
Kasey
-Fathers 1985 200X
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