Un seizing piston

[lehman live edge slab]

Talk about enough ports in that cylinder, never had a real old Mac apart but no many places to locate a ring end without hooking a port.

 

[Al Smith]

If I'm not mistaken those models had some transfer ports around the back over top the intake .The 125's had three on each side aimed above the intake .Some of the kart engines had an additional two and some early reed valves could have an additional two cut in .Which ones I'm not entirely sure of .I think the Mc 70 kart engine had 8 and the Mc 40 could be modified for 8 .By having the ports above the intake what it basically did was scavange the spent exhaust gasses above the intake which the most difficult area to purge .On modified piston ported modern engines they do it with finger ports,sweeps or externals. McCulloch did it 60 years ago .How about that .

 

[merc_man]

Well now i got the piston soaking. The rings are stuck in ther real good.

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[Al Smith]

After it soaks for awhile put the rod in a vice and use a heat gun on the piston to warm it up a but .Take a tiny little hammer and tap the rings lightly .Not like driving 20 penny nail .It might take several treatments.

 

[redlight066]

After it soaks for awhile put the rod in a vice and use a heat gun on the piston to warm it up a but .Take a tiny little hammer and tap the rings lightly .Not like driving 20 penny nail .It might take several treatments.

I had a stuck ring on a Husky L77. Had been sitting for a LONG while. Real stubborn but with a lot of patience, heat and alternating with sea foam and brake cleaner I finally got it loose. Used the old ring to clean the carbon out of the ring groove. That part was even more tedious than removing the ring. Thought I got the ring groove cleaned up pretty good for the new ring but it wouldn't compress tight enough to install the cylinder. Had to go back and pick at it some more. Carbon is some tough stuff.
Rich

 

[Al Smith]

Keven ( Cut for fun ) lives about 80 miles from me and the mail only takes about a day to get here .Had a ring stuck piston he had fiddled with for some time .He mailed it to me and I did the heat penetrating oil thing and unstuck it in about 10 minutes .Took a picture of it and mailed it back the next day .Once again there's a trick to everything .
One little trick to clean the ring grooves is a finger nail file .My wife had a collection of them as do most women .

 

[Al Smith]

Some times you get lucky .A guy gave me a 700 Mac he found in a dumpster,complete but missing the recoil .It was stuck so I just tossed it in the shed and forgot about it for about a year .Then I got the bright idea to see what I could do with it .Out came the Kroil .drowned that thing every where I could could find to squirt the stuff in .Sure enough after about week of rotating the engine a little at a time it unstuck.

I had another recoil from another 700 that had needled itself .After a little massaging it fired right up .I never did another thing to it and it's a good runner .

 

[merc_man]

Well i got the rings out. Not how i wanted but ther out in many peices. I tried soaking in the ATF for a night. Then mixed 50 to 50 with atf and acetone. Nothing. Tried heat then spray with wd 40 to try and shock it a few times. Never worked. Tried some special penetrating oil my BIL HAD. It freed up the lower ring with lots of messing with it. The top ring was just like crazy glued in ther.
Ther is also a little grove all the way around the pisting that is plugged full of this stuff.

I orderered a set of new rings off ebay so they wont be here for at least a month or so. I hate ebay for that reason but oh well. I will have to box it up for now to get it off the work bench.

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[Stump Shot]

Any oil on it before the concoction is used just hampers the process. Can't get at the rust to dissolve it.

 

[kanscruzer]

I use a screw in pressure tester bushing with a grease zerk screwed in. Pump the grease in, a grease gun pumps around 1500psi . Pump it until you get to a port, your done . once you move the piston , the rest is wooden dowel & hammer work

 

[kanscruzer]

Don’t let her know your have taken it though,or the piston won’t be the only thing seized up

Don't use fingernail acetone it's only 20-30% go to the man store and get the 100% ,,, most big box store have it.

 

[redtractor]

Used the old ring to clean the carbon out of the ring groove... Had to go back and pick at it some more. Carbon is some tough stuff.
Rich

Don't forget soaking in any of your favorite carb cleaners. Most are formulated to go after carbon. Of course, some better than others.

 

[isaaccarlson]

Any luck yet?

 

[merc_man]

Im waiting for the set of new rings to come in still. Ebay is slow

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[merc_man]

Well rings came in. Makin some progress getting it back togeather. One head bolt was stripped so had to drill and tap a little bigger. Now im at the handle.and trigger stuff. It kinda just fell apart while taking stuff off so it may be a bit of trial and error getting it togeather. Gonna wait a day or so. Got a few other things i gotta get done.

My son was cleaning parts befor input back togeather.

Oh and it does have spark. Was kinda worried id get togeather and it wouldnt.

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[merc_man]

Got the the handle assembly toheather and the recoil back on then dribbled a little fuel down the throat of the carb. Gave it a pull and my gosh she popped. Pretty eciting when ya hear em pop for the first time. Makes ya wonder when the last time it ran was.
So now im gonna move to the fuel tank. It has some white stuff innit full of saw dust. Thought i read somewhere the white stuff is a filter material? If so kine junk.
Think i will end up having to split the tank to clean up. Then will have to find a new gas cap or epoxy this broken one till i find one.

 

[Al Smith]

My super 44a has like a felt filter liner of some kind .I've got the bones of a super 44 in the shed that the tank top is bent .Let me take a peek tomorrow .

 

[merc_man]

My super 44a has like a felt filter liner of some kind .I've got the bones of a super 44 in the shed that the tank top is bent .Let me take a peek tomorrow .

The fuel cap has a hole. My first thought was a mouse made a nest? The stuff kinda looks like cotton ball material type stuff that i pulled out.

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[merc_man]

Heres what was in it

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[Al Smith]

It most likely had a screen type vent at one time .It's like some type brass stuff .I may be wrong but I think any of the large screw caps will work .I'll check that too .