JAG Hobbies

I need a little help disassembling an older Fox .45 engine. I have removed the large pressure plate on the rear and removed the sleeve. My problem is removing the piston and connecting rod. They don't slide off the end of the crank like most engines. I think the large pressure plate is for removing the wrist pin but it won't come out.

Can anyone help?

Thanks,
Jim

ZAGNUT

My Feedback: (1)

that "high back door" backplate is there so you can take everything apart once the sleeve is removed and crank is turned to BDC


dave

JAG Hobbies

I have removed the back plate and the sleeve. I turned the crank to BDC and I still can't get it out. What am I missing?

Jim

Ed Smith

As said before, with the sleeve out the rod should slide back far enough to come off the crankpin. However, even with the piston back against the case the rod may still have to slide back on the wristpin as well.

If it does not it could be that the rod is siezed/tight on the wristpin and will not move back far enough. If, If this is the case I have a couple of suggestions. Understand we are talking about desperate measures. Is it possible to get one of those small butane or propane torches with avery small flame and heat up the top end of the rod. Heat it, not melt it, a local heat on the rod only might just pop it loose. Or, maybe get a small piece of hardwood around the front of the rod to rest on and tap the wristpin/piston forward. Like I said we are getting desparate.

Just remember, that engine had to go together, therefore it must come apart.

Ed S

ZAGNUT

My Feedback: (1)

isn't the high back door supposed to allow room for the piston and rod to move back off the crankpin??


dave

Ed Smith

If the "Backdoor hole" is big enough for this to happen then with the piston at BDC just drive the crankshaft back and the whole mess will come out.

Ed S

Sport_Pilot

Fox was very inovative with reducing maufacturing costs, its my understanding the barn door backplate was a trick to reduce manufacturing costs. If the wristpin is stuck it could be due to congealed castor oil. If so heating it up may do the trick, or soaking it in fuel or denatured alcohol could also free it up.

Ramz

A good fix here would be to take a 12 lb sledge hammer and smash the engine repeatedly. This will solve your problem. I had a Fox 40....emphasis on the word "HAD". It was the worst piece of junk engine ever. A new OS 46 AX would make a very nice addition to any modeler's collection......

Sport_Pilot

I'd rather have the Fox .46. At least its a true ABC that won't peal its liner.

Motorbrain

I would never smash a Fox engine repeatedly with a 12 lb. sledge.
Rather give the a few dozen medium taps with a two lb. ball peen.
If the engine is rendered into small bits, it cannot be used for fishing
sinkers !

MB.