Female Thread Fix Help

I must also pat myself on the back. I tore down this entire engine, went thru it all replacing all o rings, gaskets, seals, bearings that needed replacing. Installed a new crankshaft, piston, cylinder, new valves, valve seats, valve guides, valve seals, new timing chain, new Hot Cams Mudbuster cam and other odd and ends. All by myself and a Yamaha service manual, and texts from my father about suggestions for some things.

It took about three weeks with me working on it for about 1-2 hours each day to complete. It should be back in the atv by this weekend and ready for its break-in. I'm proud of myself for doing this work without somebody shadowing me the entire way.
 
nice work!
i'm a little late for the party, but here are a few suggestions for the cure:
if the hole that was stripped was M6, simply tap the stripped hole to 1/4"-20tpi or 1/4"-28tpi and put another bolt in it
another way to go would be to tap the stripped M6 hole to M7, if there is sufficient backing.
Keenserts are indispensable in my industry, they are the greatest thing since sliced bread.
i hope the info is helpful to someone.
 
The helicoil drill size is just a few thousandths over the major diameter of the bolt and the helicoil tap is usually about the same size as the next bolt size up. A stripped 1/4 inch threaded bolt hole would take a helicoil about the size of a 5/16 bolt. So if there is enough meat there I would go that route. The JB Weld will work also but you need to get the hole real clean and fill the hole well for it to hold properly.
 
boostin53 said:
I must also pat myself on the back. I tore down this entire engine, went thru it all replacing all o rings, gaskets, seals, bearings that needed replacing. Installed a new crankshaft, piston, cylinder, new valves, valve seats, valve guides, valve seals, new timing chain, new Hot Cams Mudbuster cam and other odd and ends. All by myself and a Yamaha service manual, and texts from my father about suggestions for some things.

It took about three weeks with me working on it for about 1-2 hours each day to complete. It should be back in the atv by this weekend and ready for its break-in. I'm proud of myself for doing this work without somebody shadowing me the entire way.
Click to expand...

And we are proud of you too!
 
Keensert, Timesert, Helicoil are all good fixes (I prefer Timeserts). You could also create a solid sleeve insert if you have enough meat to size it up with original center thread and use Locktite to keep it in place.
 
Glad you asked the question Boost, I have learned some about inserts. Almost wish that I had some stripped threads to deal with now.
 
When ever I need threaded holes in an aluminum project. It gets SS Helicoils from the start with red Loctite.
 
I use both Timesert and Helicoil to fix motorcycle engine threads as needed. I prefer Timesert for most repairs.
 
When I was working on aircraft parts threaded holes in aluminum had helicoil inserts put in with zinc chromate primer in place of loctite.
 
You must log in or register to reply here.
Back
Top