Looks like the milling machine is coming out to play'

snowflake

snowflake

50899.jpg
 
urola

urola

What I would do is sand all around to let is at same level at very carefully, and then add a fatter or more joints together.
 
Redordead89

Redordead89

urola:
What I would do is sand all around to let is at same level at very carefully, and then add a fatter or more joints together.
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Skim and second base gasket I'm guessing!
Gotta think bout hpp system! I would prefer the long term mill n fill with alloy weld but it might work!
 
urola

urola

Sorry what means hpp?

Of course a good weld would be the best option, but not easy this welding. Hand made aluminum weld,you can´t deform anything then you must sand everything.. presure, the hot of engine, someday in winter you cross a river and with cold water, and suddenly cooled... CATACRACK:cry::cry::cry: bad weld..
Perfectly done is the best way but..
 
Redordead89

Redordead89

urola:
Sorry what means hpp?
Sorry HPP is the powervalve system on the CR250 2T, the shaft that travels up through the cases and into the front of the cylinder to operate the valves, they are very temperamental and rely on being A OK and perfectly in line to operate and if you skim or f..k about with the cases around these ports you may affect its efficiency and operation!

Of course a good weld would be the best option, but not easy this welding. Hand made aluminum weld,you can´t deform anything then you must sand everything.. presure, the hot of engine, someday in winter you cross a river and with cold water, and suddenly cooled... CATACRACK:cry::cry::cry: bad weld..
Perfectly done is the best way but..
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I agree, this can go wrong but if you are very good or can hand it to someone who is VERY good with alloy welding then it's better than a new case and rebuild and probably £50 $90-100 ish but a lot of time and hassle bringing me back to QUICKSTEEL!!! It sticks like shit to any surface,goes harder than steel and can easily be machined,cleaned up moulded or removed just like weld and at £6 per 2oz pellet it's worth it's weight in gold given the job and requirement! :hail:
I have used it underwater on a boat hull :eek:and car and bike engines and exhausts, frames and the odd DIY moment indoors and love it so much I take a wee lump every time I travel far enough to have a problem!:prof:
 
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Redordead89

Redordead89

HPP is the powervalve system on Honda two strokes of this era that travels vertically through the cases and lines up perfectly with the cylinder so if you mount an extra gasket or joint and add extra torque on the cylinder bolts to compensate for lack of potential pressure then you will likely leave slack or over tighten pressure on the racks within the HPP system..... Maybe!!! :noidea:
 
O

ossagp

I don't like the idea of two gaskets to solve the problem at hand. You change the port timing towards the advanced side and drop the compression ratio and still hope it seals. You would have a better chance at achieving the seal you want by going with the jb weld or quick steel. PAM or Teflon spray and a piece of wax paper and mine would come out smooth enough to easily seal with yamabond or even gasket cinch.

Milling it and matching the surface and tossing in line boring would be a real treat and make you feel really good.

If you want to ride it in a couple of hours, put that side together with Permatex and enjoy the fresh top end.
 
urola

urola

Redordead89:
HPP is the powervalve system on Honda two strokes of this era that travels vertically through the cases and lines up perfectly with the cylinder so if you mount an extra gasket or joint and add extra torque on the cylinder bolts to compensate for lack of potential pressure then you will likely leave slack or over tighten pressure on the racks within the HPP system..... Maybe!!! :noidea:
Click to expand...

OK, this is way must put a bigger gasket to compensate the size that you must sand. Finally must be the exactly same size.

Thank you, the are not to much two stroke Honda here.,.
 
JimYZ250

JimYZ250

Redordead89:
Hey Jim :wave: I'm up here in Glasgow, who did you the bottom end on eBay??
Breaker or private seller???
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Hey buddy nice to meet you

I got the bottom end from damagedgoodsglobal CA. - at least they lived up to there name right?? Haha.
They are being good about it though and agreed to put funds towards the repair. Just need to choose my route really. Getting it milled would put me at rest but is a pain

Jim
 
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