Seized Engine

I've got a 1990 Tomos a3 that's been sitting for about a year. i was wondering just how you would go about un seizing it. Any help would be great!

Re: Seized Engine

Do you know if its the bottom end or the top end that is seized. Top end wouldn't be very hard to fix.

Re: Seized Engine

John Joedicke /

Take the plug out and pour some Marvel mystery oil in and let it sit for a day or two.Then remove the head and see if you can roll the motor over with a little pressure on the piston. Keep working it back and forth, it probably will break free. New piston and rings probably, if the bottom end hasn't been fouled with moisture. Just as cheap to put a kit on it if it is only the top end.

Re: Seized Engine

You might not even need to remove the head. If you can get a hardwood dowel into the plug hole, try tapping it with a hammer. If it doesn't break free, give it another shot of oil (I like Kroil), and try it again the next day.

I had a 1939 BSA M20 that was stuck when I got it, and had been so for several years. Daily Kroil and light tapping with the dowel & hammer freed it in about a week.

Re: Seized Engine

John Joedicke /

Thats fine but if it is that stuck you will need new rings and honing probably.

Re: Seized Engine


Ive gotten a few Bikes and sleds goin that were siezed but some are too far gone..

The 69 CL 450 (weatherlocked) Ran Lost spark on 1 cyl

71 Skidoo TNT 340 single (Weatherlocked) Runs and goes

72 Chaprrall 340 (Weather locked) Ran But has bad bearing

Zundapp CS50 (Water Vapor locked Badly) Crank+topend Junk.

74 Canam TNT 175 (weather locked) Needs clutch cable and assorted parts

What i do is take the cylnder head off

Then put some of your faverote oil in the cylnder

Then Get an old wood hammer handle

Hit the handle with a rubber malett

If the engine dosent come free get another set of hands with a breaker arm and wiggle the flywheel nut and it should come undone.



Sometimes the breaker arm is all you need

Like with the 450 i just had to turn the engine by the crank nut and it came free.

And if the airbox or carb is not on the machene and-or has a open exaust and is siezed good chance the engine is toast.

Aslo beware of No oil siezures. On a 4stroke check the oil when you get the Bike to see if there is any oil in the engine if there isnt good chance the engine is wrecked.

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