parts interchangeability

[cuzncletus]

I haven't started on my new Wombat project yet, but I do know the engine is stuck. I've freed up a lot of seized old engines, working on one in the shop today in fact, but they've always been cast iron American V8's and the tools of choice have been cheater bars, hammers, and oxy/acetylene. I don't think these will portend well for this relatively Rolex watch of a little engine. I've been thinking about soaking the entire assembly for a period of time before I attempt to take it apart. Any suggestions about what works well as a soak for these little aluminum engines? I've used ATF/acetone 50/50 with success on bores and other parts before but don't know how many gallons it would take to submerge an engine.

I'm also anticipating an inevitable parts breakage. What parts interchange with an H cased 125, circa 75? Are cases, cranks, trannies (got to be careful with that word these days), etc. the same for several different models?

[BrianZ]

For parts compatibility:

\http://hodakapartsidaho.com/index.php/h ... atibility/

Brian

[RichardMott]

Brian,

While at Hodaka Days a few years ago, someone showed how to adapt the spark plug hole with a grease fitting. A grease gun will produce a lot of hydraulic pressure. It can force the piston down as long as it is not at top dead center.

[squid on a 300]

that may not work if the transfer ports or the exhaust ports are not covered...I had to do this a few months ago on a Husky motor that was stuck...soak the top and bottom of the piston for a few days in PB blaster. Lift the cylinder off the case to spray the bottom of the piston. Take a piece of a flat metal bar and drill 2 holes in it to fit the studs. Place an appropriate sized socket between the piston and the metal bar and start tightening. If it doesn't brake loose keep the pressure on and whack the metal bar with a hammer a few times...

[cuzncletus]

The last two were ingenious solutions. My current plan of attack is to soak the engine in a rust remover such as Evapo-Rust or ATF/acetone. I've used the latter successfully for years but have recently had good luck on small parts with Evapo-Rust. Then I'll take the entire unit, and possibly the frame, to a racing engine builder I know. We'll put as much as possible in his engine oven. The heating and cooling cycles with metals expanding and contracting at different rates often frees parts up. I want to use as little force as possible on these delicate pieces. I'll post on here my success or failure.