The Hodaka Club Forum

I have a Model 03 motor that is stuck/frozen. The rings are stuck to the cylinder wall. The crank moves freely, bobbing the cylinder up and down on the piston. I’ve been trying different solvents to try & get it free.

So far, I've tried WD40, PB Blaster, and a rust remover spray on product advertised on FB. None have worked.

Today I’m going to try acetone & ATF mixed 50/50. If that doesn’t work, I’ve ordered a product called CRC Knock’er Loose. I watched a video on YouTube where a mechanic cleaned an 8 cylinder engine with the Knock’er Loose right down to the bore marks on the cylinder walls with nothing more than Knock’er Loose and paper towels.

If the acetone/ATF don’t work, the Knock’er Loose will arrive on Thursday. I also have an Ace cylinder with a .080 piston which is seized up I will try it on. I bought a 13 oz. spray can on eBay for $12.62 tax included. I will report how the product works! Victor

No matter how long you soak it and what you use, at some point a whack with a hammer will be needed. Even then you may have to drive it all the way out.

Oh I’ve been striking it! Over & over. Yesterday afternoon I mixed 50/50 acetone & ATF. Poured it into the top of cylinder at 2:30 pm and it leached it’s way down. Added more at 5:00 and let it sit over night. I’ll go out this afternoon & check it again with my hammer. May have to go the nickaseal route if I can’t get it out without damaging the cylinder. Too bad Terry currently doesn’t have any pistons, other than standard, for the Model 03 motors. But at least it can be sealed and re-bored to fit a std piston. I only spent $80 buying this whole motor. Victor

Victor to make you feel not alone, tried all those idea for four days to no avail., on the O3 stuck motor I have, so end the end, I had to drill out piston to get it to break up and budge. The engine will have to be completely taken apart and cleaned and inspected. All new parts brg and seals will have to put in it. It the worse engine I ever tried to get unstuck. Good Luck. Bruce

I've tried and used all of the methods mentioned. If the piston is not at BDC, you can, as a last resort, use this tactic. Block up the front of the engine under the front mount with engine out of frame. Place a large steel 1 1/2"+ shaft about 3-4' long on top of the piston. Instead of a hammer, use a steel fence post pounder to strike the shaft and force the piston downward. I have used this method when the piston, rod, and crank were very rusty and various solvents & heat cycles didn't do the job.

ive never had to deal with this problem so with that in mind has anybody tried electrolysis ?

Well, I called the machine shop and they said bring the motor & they will give it a go! May have to go the nickaseal route and bore again for a std piston. Victor

You're probably going to want to rebuild the crank anyway. A crank mod to use a 97 piston and a rebore may be a more economical route it the end.

I’ve got 2 extra 94 cranks. But, one way or another I need to get this bastard apart!!! Victor

Good piece of wood and a 2 pound hammer. Make sure the crankshaft isn't on the bottom. I use mystery oil?? I have never worked on one of those, I usually am working on a hodaka. --------------Clarence-

Clarence, this IS a Hodaka. It’s a 1976 Model 03 motor. It’s just giving me fits. I hit it hard enough with a framing hatchet that it dented the top of the piston dome. You can see the flat spot the hammer left in the dome! Didn’t move the piston a bit!!!

I even tried a steel bar, bolted across the cylinder with the head bolts holding it in place. I welded a 6mm nut over a 3rd hole on to the bar and threaded a 6mm bolt through the nut to push on the piston. All it did was bend the steel stock and the screw started boring into the piston dome. You can see the divot in the center of the piston.... Victor

Just so you'll know, the Model 94 cranks you have in mind as spares won't work in your Model 03 engine. 94 cranks don't provide for the primary kick start system. You'll need a Road Toad crank with a 94 connecting rod . . . and when you do that, you can use Model 97 pistons.
Ed

Cool Calm and Collected. The framing hammer is not the correct tool. I would have wanted to save the piston if it could be. I have always used a largeblock of wood. Sometimes a large socket on the piston, still using the block of wood and a mall hammer about 2 inches by 3 inches I will weigh one tomorrow. I would soak it for a week tapping on it every day, level the engine so the cylinder is flat then fill the void with mystery oil. In 1952 I used casite?? A small hammer will peen it the larger hammer will shock it. Victor you are getting things done and that is great. looking forward to Hodaka Days. ---------------Clarence

Perhaps try a pneumatic air hammer with a hammer attachment. Use a small block of hardwood as a buffer. Get some good vibration working for you.

Marvel mystery oil? Just a thought thats what ive used to get motors unlocked

Victor, you’re gonna laugh, but Coke a Cola will free it up better than any of the solvents you listed. I’ve had two different set of forks that were stuck and tried all the different oils and solvents you listed letting them sit for days and they did not budge. Filled them up with Coke and they came apart within a day.
You’re probably thinking “man, this guy really is a goat roper” but it was the only thing that worked.

Diet or Classic? Makes you wonder about drinking it....

I’m going to give Coca Cola a try! I know it will dissolve a 8 penny nail over night! Worth a try! Mac, thanks for reminding me! Off to 7/11 to get a Coca Cola NOW!!! Victor

No diet, only Classic ! Lol

I've had success freeing up Cadillac flathead V-8s with dry ice. Talk about stuck!

Seems like anything that reacts to iron/steel would be tough on the cylinder.

Well my can of Knock’er Loose came in last night. Off to spray it onto the piston now to see what it does. I’ll post any/all results. Victor

MTrat has a good point about Cola maybe hurting the cylinder. I think, like Clarence said, it just needs to soak and then patient persuasion with hammer and wood. I also like the muffler gun idea.

Well even the CDC Knock’er Loose didn’t work.

Then I started thinking about what I’ve used to remove rust and varnish, you know, from inside fuel tanks!

So, I poured some Muriatic Acid into the top! It bubbles away like soda poured in a glass! After about an hour the Muriatic Acid becomes like syrup. I cleaned it up twice and am on my 3rd dose of acid straight out of the bottle. Attached is a picture of the stuff! Victor

Victor,
What happens when the Muriatic Acid eats through the piston and gets into the cases? It eats aluminum doesn't it?
Dale