Corroded exhaust port threads


Old 05-11-04, 06:47 AM
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Join Date: May 2004
Posts: 11
Corroded exhaust port threads

My Troybuilt tiller engine's exhaust port threads are corroded. Am I correct in believing that it requires a 3/4" 14 NPT tap to refresh the threads? Also, is it a tapered or straight thread? I plan to use a 3/4" nipple to attach a screw-on muffler as I managed to snap off both mounting bolts and a broken bolt remover (Any miracles that might apply to the broken bolts would be appreciated).

I forgot to add to my first posting that it is a Tecumseh 6 horse engine.

Last edited by zchief; 05-12-04 at 05:40 AM.
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Old 05-11-04, 07:30 AM
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Thumbs up Miracles Can Happen

Hello: zchief. Welcome to the Do-It-Yourself Web Site and our Small Engine forum.

The needed "miracles" are about to appear. Plenty of advice from the pros in this topic. Refreshed Corroded threads, had or caused broken bolts, busted easy outs, &&^%$$#@[email protected]!......we have all been there & done that......those of us whom have not are not experienced enough...

Use a tapped die to clean out the threads. Use oil on the tap and turn it in and out carefully, little at a time. Cleaning off the tap threads often, if needed. Much of the process depends upon how corroded the threads are.

Use a tapered die, since the pipe is also tapered. Apply oil to it's threads also during installation. Dry threads create friction which creates the false illusion of being fully threaded in. May not be so when installed dry. (IMO)

If the existing bolts cannot be removed with a easy out tool, grind them flat if need be. Or leave them as they are, if possible. Enough has already taken place with them. Focus attention on the alteration about to take place.

Be sure the new muffler is correctly sized for the horse power of the engine. Also insure the exhaust faces away from the intake and the cooling system.

Including the engine brand and model may help to know more exactly what the needs are but are not required for general purposes.

Most likely I haven't covered all of the possibilities. The resident small engine service and repair professionals in the forum may be able to offer additional suggestions, advice & help.

Check back on your question several times over the next few days for additional replies.

Small engine repair parts, generic repair manuals and additional help are all available at all local small engine repair shops and or lawn mower repair shops in your area. Shops and dealers are listed in the phone book directory.

If you need further assistance, use the reply button. Using the reply button moves the topic back up to the top of the daily topic list automatically & keeps all communications in this one thread.

Regards & Good Luck. Sharp Advice.
Master Small Engine Tech. Web Site Host, Forums Monitor and Multiple Topics Moderator. "Accurate Power Equipment Company." Engine Diagnostics Services & Repair. Fast...Fair...Friendly & Highly Proficient Services.

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