Stripped Magneto/Breaker Hole

[FredoTwoWheels]

The hole that holds my magneto secure is stripped. I have some 1/4-24 helicoils, but no insertion tool and I need to get up and running quick. Would I be better off drilling it and tapping it for 5/16 or should I attempt the helicoil without the tool? How much meat is surrounding that area in the case?

[Thunderbird]

make an insertion tool? they're pretty basic.

[CookieMonster]

Do you have the tap? Proper Helicoil taps are not necessarily standard threads and usually come in the kit. An insertion too should be easy to make.

[johnjzjz]

any 1/4 inch insertion tool is the same its not thread specific like the tap


seen many made 5/16 to repair second or third time maybe - what we did was drill and tap the 5/16 to 1/4 X 24 double nut the stud we make from a bolt and install it back to original - welding is the other way

[FredoTwoWheels]

It was my understanding I would need an insertion tool of the same thread. I read about making one by sawing a slit in a bolt, but the only 1/4-24 bolt I have is the one for the mag, and I had to order it off ebay they are not easy to find (or were not when I was building the bike) If the tools are not thread specific though, I'll just go buy a 1/4-20 kit and use the tool, thanks guys.

[johnjzjz]

Originally Posted by FredoTwoWheels

It was my understanding I would need an insertion tool of the same thread. I read about making one by sawing a slit in a bolt, but the only 1/4-24 bolt I have is the one for the mag, and I had to order it off ebay they are not easy to find (or were not when I was building the bike) If the tools are not thread specific though, I'll just go buy a 1/4-20 kit and use the tool, thanks guys.

it is thread specific and worse then that if you run a 1/4 X 20 tap and not a heli coil tap you will do two things


first - you will only end up with a 60 percent thread using a 1/4 X20 tap and we are talking about aluminum - it will strip right out again as it s not deep enough


second thing - if you use a 1/4 X 20 tap and that happens = step two - the 1/x4 24 heli coil is also compromised as the course thread 20 is deeper and the 24 thread is considered a fine thread and the coil thread will be shallow not as shallow as with the regular tap BUT <<<<<


this is the reason in the end so many have a 5/16 X 18 thread and the bolt head need to be modified to use it on a mag

in the end its all effed up and still not right going the easy way


your choice - do it right the first time - or what ever happens happens

[ericthebeard]

Originally Posted by johnjzjz

it is thread specific and worse then that if you run a 1/4 X 20 tap and not a heli coil tap you will do two things


first - you will only end up with a 60 percent thread using a 1/4 X20 tap and we are talking about aluminum - it will strip right out again as it s not deep enough


second thing - if you use a 1/4 X 20 tap and that happens = step two - the 1/x4 24 heli coil is also compromised as the course thread 20 is deeper and the 24 thread is considered a fine thread and the coil thread will be shallow not as shallow as with the regular tap BUT <<<<<


this is the reason in the end so many have a 5/16 X 18 thread and the bolt head need to be modified to use it on a mag

in the end its all effed up and still not right going the easy way


your choice - do it right the first time - or what ever happens happens

I think what he was getting at was if the insertion tool is not thread specific, then he'll just buy a 1/4-20 kit and use that tool for the 1/4-24 helicoil repair on the case?

[FredoTwoWheels]

I have the helicoil tap for 1/4-24, I just broke the thread installer tool. What I meant was that I would buy a kit and just use that installer tool.

[JasonMcElroy]

If you've got an extra 12-24 screw you can just grind a relief into the end so that it can be used as the installer.

If you grind half of the diameter off the threaded end about 1/8" deep (this is HARD to describe) it will engage the the tang on the coil for insertion. If you look at other installers you can see it better.

Jason

[johnjzjz]

Originally Posted by FredoTwoWheels

I have the helicoil tap for 1/4-24, I just broke the thread installer tool. What I meant was that I would buy a kit and just use that installer tool.

I was just making you aware of the mistakes others have made


glad you have it under control