'86 250R refurbish

**Kamnahrt** · 08-08-2018, 10:39 PM

Got the rear fenders buffed and everything is finished aside from the decals that should be in friday.

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**Kamnahrt** · 09-02-2018, 07:10 PM

And the saga continues... Let me start by saying my dad always preached murphys law, but in my own opinion I think he was an optimist.

Took the old girl out for final tuning now that I had some time got the jetting dialed in and was cruising back to the truck to start messing with needle positioning. Got half way back and it started acting like I was fouling a plug, wouldn't rev was choking on itself. Then all the sudden the sound of metal on metal clicking then a final pop as the wheels and everything locked up.

As you can see the bottom part of the sleeve, that goes into the crankcase, grenaded. Looking at some of the bigger chunks it appears this was either an existing crack that was missed by both me and the porter or possibly a material flaw.

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**Gabriel** · 09-02-2018, 07:44 PM

That sux!

I had a 1979 Suzuki PE250 that did that with nauseating regularity. Between my junior year of High school till christmas of my senior (when i sold it) it must've done it 5 or 6 times. The first one happened because the anti rotation pin on the compression ring was passing over a port. That's a no-no. The other times, I never understood it. It happened once in a mud hole and I was pushing the engine full throttle for too long...stupid hard, I guess that one made sense too.

Sorry. Hopefully you can track down all the pieces and don't have to split the case.

**ironchop** · 09-02-2018, 08:44 PM

Awe dude.

That sucks.

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**yaegerb** · 09-03-2018, 01:38 AM

Catching up on this thread only to witness this carnage. Did you have the cylinder bored to the piston? Takes a lot of slap to break off a dog ear.

**El Camexican** · 09-03-2018, 08:37 AM

Originally Posted by yaegerb

Catching up on this thread only to witness this carnage. Did you have the cylinder bored to the piston? Takes a lot of slap to break off a dog ear.

Yeah, that choking on itself explanation sounds an awful lot like a seizure.

**Kamnahrt** · 09-03-2018, 11:01 AM

Gabriel: At this points its all gotta come back apart. There are bits and pieces scattered throughout everywhere.

Ironchop: Some days you're the Hammer, some days you're the nail. At least it gave me an excuse to uncork a new bottle of whiskey last night. Gotta look at the positives

yaegerb: Yes, the same gentleman that ported the cylinder also bored and honed the cylinder for my new piston. When I checked it after I got it back, I was ~.0026" clearance with about .0005" of taper from stem to stern.

El Camexican: Based on the condition of the cylinder wall and the piston wall I do not believe it was starting to seize. Other than some grooving from FOD there is no apparent galling to be seen. Again Based on the failure area it looks like there was a lot of old break/void in the casting. Why it waited to come apart after I built it and not on the ice last winter, that Murphy guy is an optimist.

**Aulbaugh** · 09-03-2018, 11:58 AM

ouch. That sucks to be tuning and have that problem! Time to spend some more money. Hopefully that whiskey washed away the problem mentally for a bit.

**Kamnahrt** · 09-03-2018, 12:04 PM

Originally Posted by Hondatcs

ouch. That sucks to be tuning and have that problem! Time to spend some more money. Hopefully that whiskey washed away the problem mentally for a bit.

I have yet to find a problem good whiskey and a back porch cant ease. But I got to looking at the sleeve again this morning and it appears the other dog ear is cracked as well.

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**yaegerb** · 09-03-2018, 12:29 PM

I would just send it to LA sleeve with a stock size piston kit. Let them resleeve it for you. They take approx 4-6 weeks but it will be brand new when you get it back.

**Gabriel** · 09-03-2018, 12:34 PM

Dang that's an expensive hit.

The older I get the more I keep (re)learning it's really difficult to beat bone stock. Don't get me wrong, I am NOT berating the decision to port the engine but I wonder if that didn't make it weak?

I had every intention of doing a full port and polish, XR200 cam and bigger carb/exhaust on my current 200ES build and have talked myself out of it. After talking to more knowledgable people, the problems I am going to run into for such an endeavor ain't worth the gains.

I hope you get this squared away. ATC parts are getting harder and harder to find. Every part lost.....

Good luck buddy. Keep us apprised.

**El Camexican** · 09-03-2018, 12:42 PM

Originally Posted by Gabriel

The older I get the more I keep (re)learning it's really difficult to beat bone stock.

I’m about getting there myself. No more records to be set in the three wheeler world, so why to we keep dicking with what works?

**Gabriel** · 09-03-2018, 02:27 PM

Originally Posted by El Camexican

I’m about getting there myself. No more records to be set in the three wheeler world, so why to we keep dicking with what works?

20 years ago I'd be all over the fastest thing on earth. Now, my 200cc's are PLENTY. The way i see things now, anything past 3rd gear low range and I'll just end up dropping my fishing pole and spilling my beer. Who needs that complicating good living?

**yaegerb** · 09-03-2018, 02:47 PM

So, post 56 I am seeing some troublesome work done by your guy. First off, there are no cross hatch marks in the cylinder which means your rings will have an extremely hard time seating....if they ever do. The other thing I see is in the last pic, showing the exhaust port. If you look at the bottom on the right and the left I see two grey smudges which are indicative of a stressed cylinder wall. What’s more is if you zoom in on the right side I see a grey line going through the smudge which to me looks like a crack. Did you thoroughly inspect this cylinder when you got it back? The porting looks like a high CR port as well. Who did this work?

**Kamnahrt** · 09-03-2018, 03:32 PM

Originally Posted by yaegerb

So, post 56 I am seeing some troublesome work done by your guy. First off, there are no cross hatch marks in the cylinder which means your rings will have an extremely hard time seating....if they ever do. The other thing I see is in the last pic, showing the exhaust port. If you look at the bottom on the right and the left I see two grey smudges which are indicative of a stressed cylinder wall. What’s more is if you zoom in on the right side I see a grey line going through the smudge which to me looks like a crack. Did you thoroughly inspect this cylinder when you got it back? The porting looks like a high CR port as well. Who did this work?

There was a good crosshatch in the cylinder. The pictures don't show it well but it was there. Yes I inspected it very well, but that doesn't mean I didn't miss something. The little smudges and line I see what you're saying but it very well could be fingerprints or stressors. At this point I cannot say. The porting job is supposed to be a mid-high range port, unfortunately I'm not inept enough of what it should look like to judge that. As far as the gentleman that did the work, its Kinny Racing here is Wausau Wi. He has a great reputation locally with the 2 stroke guys.

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