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The bike is affectionately nicknamed ‘dog’. 1995 Scorpa Easy 250. I bought it from someone at the local trials club as a fixer-upper but it wasn’t quite as cheap as it should have been.
When started there was gear oil dribbling out the wrong cap, and coolant sizzling from the exhaust/rad. The lower fork clamp also had a crack in it. The fan was a big 12V job but poorly fitted. Wiring had come loose too. It became apparent it will be a labour of love.
The bike has spent the last couple weeks in a friend’s garage while I made space in my shed, so I’ve only had a few hours across two days to work on it.
So a friend in Shepton Mallet had a spare front end (forks, clamps, wheel, radiator, fan), rear suspension, Ducati stator and CDI, from a 2000 Sherco 2.5 Graham Jarvis.
We fitted the Sherco clamps and fork, original wheel, and replaced a few bolts. Fitted a correct size plug for the gear oil.
I syringed maybe 30ml or so of 2T oil into the plughole and cycled it a few times, then left it for the week, I hoped at least a little would seep down toward the mains. I was recommended “soak it in diesel” by an old 2T rider but didn’t have the guts.
Ordered the correct radiator from a breakers, fitted the Sherco fan, refitted and filled with coolant. New brake pads front and rear. Rear was bled but wasn’t necessary. Front was bled but needs more work still.
Clutch master appears to be leaky. Pressure one minute not the next. Going to rebuild, but have an Amazon special that should get me by, at least to test the clutch action.
We have a new front tyre to go on, and a near-new rear. That’s an impending job. Also need new unworn snail cams, fabricate a kickstand mount and kickstand, and some other bits and pieces I guess.
So yea, about 4 or 5 hours in and we finally kicked over the bike to make sure nothing was leaking out. It’s rattly and noisy.
I could live with the noise, so long as it doesn’t seize the engine the first time it gets used for more than 5 minutes.
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pdlouche
lynx
Find out what’s up with it first. I’d start with compression, if that’s low it could be ring sealing or just the bore getting a bit tired. Pull the top end off and inspect and measure. There’s generally some degree of cross compatibility on two stroke pistons, but before you get into that, see what OEM / aftermarket ones are available. If there’s no damage, measure the bore and order the next oversize. They generally come in increments of .25. Then take the new piston and barrel down the machine shop and get them to bore it. Cast pistons need less piston to bore clearance than forged - so make sure they know what you have.
Old air cooled two strokes are pretty rattly even when they are fresh. The couple of Rotax engines I’ve played with also had straight cut primaries that make a racket.
If it’s been sat unused for a long time, the crankshaft oil seals are often suspect. Just go slow - two stroke engines are mostly a doddle to build.