250-500cc 94 WXC-250 rebuild / help

There's only 1 way to find out
Get a diamond hone on that baby and see if she cleans up and how round she is.

If it cleans up then you're golden.
And if not, then it's another $200 for a strip and re-nik job. You're still ahead of the game

Looks like it wasn't warmed up properly before getting hammered on....once upon a time. Maybe that's why it tossed the old owner

I've read that before too, but never tried it. I'd be nervous using acid on the coating.

I melted a piston once and took the jug to guy in Milwaukee with a diamond hone. He cleaned the cylinder up perfectly in about 5 seconds and it looked about the same as yours does. Didn't even charge me since I bought some rings from him.

I talked to Eric Gorr for a while and he said it's best to start fresh, whatever the method. He's got quite the package deal as well.
* Cleaning and disassembly
* Inspection and measurement
* Over-boring
* Porting
* Replating
* Diamond honing
* Head mods
* Powervalve service
* Piston and gasket kits.
all for about 500 is what he quoted me for my 01. I'm sure it would be less if you already have piston/gaskets.
That is to put it back to stock, it's more for the 275 kit.

Kelly,

Muriatic acid(Hydrochloric acid) is doable if you have a steel liner but is very easy to screw up. We used to use it on Ski Doo's back in the early 70's when they had the high speed jet adjustment in the riders lap where he could try for the extra little bit of power that caused a zillion problems and they wanted it running again that day with no cost.

I would definitely start fresh and a steel liner is a nice solution. It is not like these husky 2 strokes run hot and you have to have immediate heat transfer.

That is the same PV setup as the WR 360, very simple and effective. I switched my 360 to the boyesen 2 stage reeds for the 360 and with the conversion to the PWK made a huge difference in low end response time and ease of jetting.

The only thing you need to be aware of is your current carb has an intake end spigot that is about 2 or 3 mm larger than the 38mm pwk airstriker. You need to either make a bushing or if your intake boot is still supple it has enough give to be able to just tighten it done the extra bit on the pwk spigot. I have been running my 360 this way for 2 years with no issues. Also check your intake boot/reed valve cage alignment. This was an area I achieved huge gains by matching these areas up and removing the copious amounts of extra material.

Keep us informed as you make progress,
Walt

Done this many times back in the day with great success. Use a "Q-tip" and just smear it on the aluminum in the bore, of course.

Good deal!

Hey Kel,...I know you've been riding a long time and you know your way around bikes, and I don't mean to be preachy or anything. But I've been riding two strokes for about 35 years myself, and Robertaccio and Ajax are straight up right on this one. When you wind a 2-stroke out to the moon and then chop the throttle you're not only robbing the piston and cylinder walls of lubrication,...but you're also robbing them of the cooling effect of the atomized fuel mixture as well,...and at the absolute worst possible time too. Seriously man, don't do that. Pull in the clutch and blip the throttle a few times, and use the brakes,...or do the Ajax kill switch method and at least take the fire out of the equation.

Pistons in backwards...
































made ya look!!!


Later,

Gosh that sure looks good to me,...looks like brand new almost. You're the fastest top-end wrench I've ever seen!

And,...I of course have no way of knowing that the high speed chop is solely responsible for causing that bike to sieze this particular time. I'd be a fool to presume that from 3000 miles away. I'm just sayin' as a general rule,...that ain't good for 'em. You can see the reasoning why,...right?

good job!! the cyl looks great,
PS I was referring to that motor regime, the throttle chop from hi rpms, that it is a critical place for good jetting. I have never used any special methods while riding (like others do) , just have the jetting dialed in properly.

just a reminder Keihin and Mikuni use different measurements for jet size. I think that Sudco has a chart for X ref. Again great job on the cyl clean up looks really good.

subject change, just walked around the pits at the speed fest here at NAS NI , wow some real super classic race cars here (again). The ferrari 312,,was my fave of the day with the 917 porsche turbo (mark donohue car) next, love those GT (P) cars open and close cockpit types.

Kelly,

Nice job That PJ will still be better than the TM that came on the bike stock.

PS, we still need picks and reports on your WR 125 suspension. I am really interested in what your friend thought of the power potential of the 125. It is official end of season here(hunting season) and time to muck about with your bikes.