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90 XR200 piston damage

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I am doing a top end rebuild on a friends 200 and saw some unusual damage in the cylinder when I took it apart. 

It looks like the piston and head gasket were making contact.  Anybody ever see anything like this before?  Wrong head gasket?  Head over decked?

The piston part number shows it as a model correct Wiseco piston.

piston1.jpg

piston2.jpg

piston3.jpg

piston4.jpg

What do ya'll think?

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I wonder if it was put together using an XL 

or ATC 185 head gasket. They are 63mm in the bore. That might explain the whacking. If you sit the head gasket back on does it overhang the bore?

 

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Just getting back to this bike.  Had a weather delay--named michael.  What PITA!

 

Anyway, it had to be the wrong head gasket, it is not close to the right size.  I was thinking maybe it was a missing dowel or something letting the gasket slip to far to one side and making contact, but any way it sits is too small.

 

At least it will be right when it goes back together.

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Stay away from the 67mm piston if possible.  The liner gets so thin that cracks are common.

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20 hours ago, Woodspike said:

Just getting back to this bike.  Had a weather delay--named michael.  What PITA!

Hope you, your family, and friends all made it through unarmed, and with little to no loss. 

Did your friend have this motor rebuilt, or was it rebuilt before he got the bike? Just curious how long it had been running that way

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Everybody in my part of the world is fine, 50 miles west is a different story.  We had power back within a week, they might not for months.  That is hard to believe in today's world.  I have heard some schools won't reopen until January!

 

I first rode this 200 right after he got it in April of 2012.  It smoked like a fog machine then and I know he hasn't wrenched on it since.  No telling what happened to it before that.

576358_3737197665504_1831297478_n.jpg

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9 hours ago, greenhuman said:

185 head gasket

Has to be.

I am thinking there was a lot of time low on oil and not any regular oil changes.

toms1.jpg

toms3.jpg

The pin was very rough, I had to drive it out.

toms2.jpg

The cylinder is rough, but I think it is stock bore size. 

I will get my machine guy confirm before I order the piston.

toms4.jpg

Lots of piston abuse, it looked like this all the way around.  Top 2 rings were seized in the groove.

 

 

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I'd be changing out the conrod. It's bound to be scored and could grab a new pin quick smart.

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A full top and bottom end rebuild is warranted. You may need to replace the crank as well with that kind of top end damage. But crank main bearings, con rod and bearings, cylinder bore, piston and rings are a definite. I'd also check your cam, cam journals, and valve stems and guide's. Poor oil maintenance coupled with seriously low oil levels can have a devistating effect.

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Well, darn.

That cylinder is hosed.  66mm already and unlikely to clean up without going to 67--maybe not even then.  Rust issues.

New cylinders are hen's teeth and ebay is full of ones in the same shape or worse. 

What are the options here?  New sleeve seems to be $100 plus labor. 

Anybody have any good ideas or leads?

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buy an xl185s, atc185 or xr185 cylinder and get it bored to xr200 stock dimensions. I agree with above comments that new rod and very close look at all bearings/oil pump/+ cam/cam journals/cam chain sprockets etc needed given the state of that thing.

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So I could get a xr185 cylinder like this one:

https://www.ebay.com/itm/1979-Honda-XR185-HM460B-Engine-top-end-cylinder-head-jug-piston/232222706955?hash=item36118d4d0b:g:MEsAAOSwA3dYfjrK

and have it bored to a stock 200 spec?

Would the 200 head, exhaust and carb work with it as is?  Or is it a major undertaking with sleeves and other reasons not to jump on it?

 

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Install the late oil pump, only one avail from Honda, it has 50% more capacity than early pumps and supersedes them.

The 79 cylinder and head are the same except for bore, it will bore out to 65.5 or 66.0 mm. Cam is also the same. And it fits the crankcase and exhaust.

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