1966 T120, engine been sat since 1978, and is locked solid. No movement at all using kick start. Looking down plug holes it looks pretty nasty and rusty in there. How best to get it free'd up without causing irreprible damage to bore / pistons / rings ??? Open to suggestions, thanks
Pour diesel down the plug holes and leave overnight This is only to get the pistons moving I doubt you’ll get it running if it’s been sitting since 1978 Even if you do you’ll probably damage the pistons and bores beyond repair Far better to at least get the head and barrels off
I would be oiling every bolt on it, waste a couple of tins of spray 3 in 1 all over everything, or fill the bath with a thin oil and submerge the whole bike for a week. Your going to have to go in to the engine so start making it as easy as possible to get there. Make the whole bike a oily mess. Look at the engine mounting bolts especially. IMHO
Surely a full strip down is required, gears will be rusty as will bearings, trying to get it running without is asking for trouble in the long run.
Seen kerosene / diesel / ATF / acetone / oil all in various concoctions being recommended. Have a couple of those handy so will give it a try. Currently sat with oil in, but that doesn't seem to be having any effect, but can only do good to the bores if they are corroded. Alloy pistons, steel rings, what are the barrels made of on these old bikes? Cast iron? If I get chance. I'll go scrape a bit and see. Thanks for the input, as always. Keep it coming.
Diesel is what I would try. Heard it works well but have you tried the key first Looks for somewhere to hide.
Chucked some oil in when I viewed it, one side is full, but other empty ???? But I didn't put it in, so can't be sure both got done! Going to pull the oil out tomorrow and try the kerosene & acetone mix for a few days, see how that goes. Been looking for an hour now, can't find the bloody start switch! Anybody know where to find it on a '66? And what's the big pedal behind my right peg for?
Lubricate with diesel for about 1 week then turn over slowly with a spanner on the crank. Check ports as you go - It's a job not to be rushed. Good luck hope the internals are ok
Remove the cyl head with engine in frame and put some WD 40 in the bore that is stuck and with 2nd gear selected rock bike back n forth, you can cut down old feeler gauges to poke any piston to bore gaps to encourage fluid penetration
Try using hot molasses, mix with distilled water, molasses eat/ dissolves iron based rust/corrosion. It's used by quite a few of the local vintage car and motor cycle restorers here in Australia. Heat the bore/motor up a few times , then add some oil based lubricant before trying to turn it over, I got a Yamaha 850 triple to free up using this method, the owner took it back once it was able to be kicked over. He got it running again some 18 months later. Not sure how much he did in way of stripping down.
Al this talk of how to free the pistons in the bore is fine but what about the rest of the engine? Full strip down, only way to be sure it’s all ok.
One step at a time, no point doing anything else till you get the pistons free. Then as you said a full strip down and check bearings etc
you have seepage, good molasses will work on rust/corrosion in the bottom end too. put some in gearbox if that proves to be seized too
Will get done. But first if I can get pistons moving, be easier to disassemble the rest. Then we'll look at a full strip, strip, clean and assess. Maybe there was a reason for parking it up in the first place, so if I find knackerd bearings, be no big surprise. The old boy never let on, but I've been here before with various classic cars, so pretty much expect the unexpected when you start to open these cans of worms. After end of first day, already found out it's had various upgrades and changes over the 12 years it was on the road. So we'll see.
I would start by being suspicious of why an otherwise serviceable bike was parked up and neglected. The ‘patina of age’ look is fine up to a point but really makes no functional sense for wheels, suspension, engine (less covers) and drive train. Viewed as a fun investment, a proper nuts and bolts restoration makes more sense. Having soaked the internals I would be having the heads off to see if the pistons can be tapped with a lump of wood to inspect the bores for signs of broken rings etc. The storage conditions matter too if there have been cycles of condensation allowing major corrosion (a re-bore job) or merely fresh honing. The main thing is patience and pleasure in a job well done.
By the way, if you pm me I have an ultrasonic cleaner that does a fantastic job on carbs. I assume you are not too far from Drumfries?
