mxerman

Any one know how I can get my Magnum 120 4 stroke exhause threads repaired? Threads are gone in the head. I can't find a heli coil in M14x.75. Any ideas? Thanks, mxerman

fasterjman

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I work at Lowe's and I have seen where we carry different types and sizes of taps and dies. Maybe theres one the size you need. Jeff

Sr-Telemaster

Clarence Lee he has ads in the Mags. very reasonable.

mxerman

Some one mentioned that name to me. Does anyone know how to reach him? mxerman

Yogi

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Look in the classified section of Model Airplane News or Model Aviation Magazines, Had my glow plug thread repaired in an OS 70H by Clarence Lee. His work is flawless and turnaround is fast you had to look real close to even tell there was an insert there. Yogi

LDaba

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Mxerman: Another solution would be to use J.B. Weld to repair the hole. This is alot like epoxy and should work well in that application.
It is important to thoroughly clean the existing holes. Use acetone or denatured alcohol to remove all traces of oil.
Fill the holes with the weld mix and after it cures, pilot drill the holes, re tap with the correct thread and you should be back in business. Happy landings, Tony.

mxerman

I thought about JB Weld but.....the exhaust pipe threads directly into the cylinder head. With the vibration and heat, plus the muffler weight hanging off the end of it I can't see it holding.. Has anyone tried it? Thanks..

pub

try McMaster carr pub

JohnMcGowan

My Feedback: (15)

If the JB Weld gets bumped around with the muffler , it IS going to come loose, (ask me how I know, lol)
Go the the engine forum and do a search for Clarence Lee and his contact info should come up. Sending it to him to fix will be a sure thing and you wont have to worry about it again.
Best of luck with it,
John

John 38

I used JB weld for stripped threads on an OS 90 4 stroke - only held for a period then worked loose so had to keep redoing it. Vibration and not enough thread working to hold tight eventually cracks/powders the JB

the trick to avoid weld getting into engine ( after cleaning threads as much as possible0 was to smear weld on silencer threads and then screw in. this prevented jb weld being pushed into engine, but of course limits amount of weld available to do the job. the problem was to try to tighten as much as possible without slipping the thread on the stripped threads . If it did, I had to strip out reclean and try again.

eventualluy got a friend to cut new threads and make new silencer insert - so go with Clarence and similar solutions

catracer343

I'd drill it out to the next bigger size (10-32?) and re-tap it. You'll just have to buy bigger bolts and possibly drill the holes in your muffler out a bit too. -Craig

mxerman

Thanks all for the help.. I found the address, phone number. I will post it for anyone else that may need their service. Its...

Clarence F Lee MFG Co
10112 Woodward Ave
Sunland, CA 91040
818-352-3766

Rodney

Note: Mr. Lee requests that you send only the head, not the complete engine, when you ask him to repair stripped threads. His service is fast and reliable.