RZ/RD 350 & Misc. 2-Stroke Tech BBS

hondaror wrote:That wear is excessive piston to bore clearance. The piston was rocking front to back.

Yer i believe your right. I pulled the other jug and it shows something similar although not as bad. I have read that Back in the hey day of' racing 2 strokes, buyers would ask to pull of a cylinder to gauge crank and bore condition before settling on a price of the' bike. Anyone have or know of a set of cylinders for sale? I saw one right cylinder on Canadian ebay. That could be a start.

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The other cylinder, right side.

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I asked my mate about cyls and he doesnt have any now, sorry.

Ask in the wanted section of this forum, you never know your luck.

thanks for asking jon w. i'll post up in the wanted section. I think boring to 2.5 over could be as they say false economy. i'm open to advice from here.

you can have them sleeved is another way, but with mixed results Ive heard locally, less so in the UK where people seem to go that route.

i have been offered a pair of cylinders from a good forum member, both cylinders standard bore. Only trouble is one of the cylinders (right cylinder?) has suffered damage. i asked to get a second opion to it's viable condition. To me it looks like it may be to damaged to bore out without at least going to max 2mm overbore. probable hard to really know without boring to find out. looks like left cylinder would be good. anyone have a right cylinder? if i'm going to spend the money (allot) i would like to start at least only +1mm to allow future rebuilds. opinions welcome.

Photos

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I would stick with what you have till you find a set you are happy with.

Wow, that's a lot of damage. My machinist eye says it needs a lot of attention. Only a good deal if you get them for a bargoon of a price.

that last pic screams for a re sleeve.
must of ran for a while with the piston in bits to cause that much carnage.

Found some cylinders in Australia. Standard bore.

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Ok i bought some accessories to.

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Nice find.

Its nice to have a spare engine. I've got two complete motors for my LC. I just switched to motor #2 last winter. Motor #1 ran in the bike for 3? years. Now Motor #2 will run for a few years and then I'll switch them again. This way I always have a motor ready to go and no motor sits idle for years to get rusty inside. :D

Kicking myself that i didn't spray starter fluid around carb joint to check for leeks. there had also been a little bit of oil around outside of reed block that i haden't noticed. i went over this bike for hours before running it up the road.

I had a badly leaking reed gasket and spraying carb cleaner around the reed block had zero effect. The primary symptom was an elevated idle.

Now, as a result of that experience, I use grey motoseal on all surfaces of the reed block and spacers. No leaks since.

Thing is i didn't at the time recognise the bike had seized at the top of that hill. It's since travelled another 200k's and i thought it was running great.

A friend tore down his 2-stroke enduro bike to discover a big piece of nikasil plating had flaked off. Strange thing was he never noticed any drop in performance, even though the position of the flake should have resulted in a large loss of compression. Short of a serious seizure I think a 2-stroke engine can tolerate a fair amount of cylinder/ring damage or wear and still run fine.