Stripped head bolt "non venture"

[Eddie Fulmer]

This could be a problem on any bike and I need some advice on it. We found the head bolt loose on a Yamaha Radian. I think that's the name. The threads were all on the bolt. Of course the bolt goes through the cylinders and is close to the middle of a 4 cylinder inline engine. Is there a way to repair it? We havn't had the bike apart and it doesn't appear that the head has been off. I've had several ideas but need some input. We really didn't want to take the engine apart. Is there a way to rethread it or maybe a stud that is self tapping with a larger set of threads. I had some head bolts that pulled out of a VW engine years ago and I found a replacement that you could put in that cut it's own threads.. That worked great long ago. Any ideas?

[utadventure]

Eddie-

 

Google Heli-Coil (I've seen them at Pep-Boys).

 

My son had a valve cover that the threads were stripped out. We found the appropriate Heli-Coil size, rethreaded the hole and inserted the coil and it is holding the bolt in perfectly.

 

Good luck on your repair.

 

Dave

[skydoc_17]

Being a Machinist, I have seen this more times than I care to think about. If you don't want to remove the head to get to the block then two products come to mind. Both are used the same way. The first product is a Helli Coil. you would run an oversized tap into the hole with the stripped threads and retap it for the Helli-Coil which would return the thread to the same size it was before being stripped out. You use the installation tool to install the coiled wire that returns the thread to the same size.

The next product is a Keen-Sert. Same principal, Tap the hole with the oversized tap, only with this one, you put the Keen-Sert on the end of the head bolt and screw it in. There is lock tite on the outside of the Keen-Sert and once you torque the bolt, the Keen-Sert is locked in place. If you find that the hole in the block is too far away to reach with the tap, braze an extension rod on the end of the tap, this can be done with a small cylinder of MAPP gas sold at any hardware store. I think these are your 2 best choices for a lasting repair that will allow you to remove the bolt later. It's a shame you don't live closer, I could take care of this for you in my "little shop by the creek"!

Good luck,

Earl

[flb_78]

http://www.drillspot.com/products/447448/Loctite_28654_Stripped_Thread_Repair_Kit

 

 

• Makes permanent repairs on most metal threads in 5 minutes; allows up to 1538 in.-lbs. torque on a 1" bolt.
  
• Resists most shop fluids.
  

 

• California Proposition 65 Warning: This product contains a product known to the State of California to cause cancer.
  

It causes cancer so you know it's gotta be good.

[saddlebum]

Keenserts are great because the are solid , on the other hand helli coils offer extra long coils for more and deeper threads. Used them both love them both. used the fast thread repair chemical products too but they can be hit or miss.

[Eddie Fulmer]

How's about a good idea to get the shavings from the deep hole. I think I have a heli coil that is the right size. I don't think I can reach into the new threads and break off the little installation tab on the coil. Glad I have some "ponder" time here. Thanks for all the responses.

[utadventure]

The mechanic that taught us about the Heli-Coil recommended that we use a screwdriver to break off the install tab. Then he said they take the air hose and point it at the edge of the hole and using short blast are able to clean out the hole.

 

We also used an extendable magnetic pick up tool to grab most of the shavings (won't work if the block is aluminium).

 

Dave

[saddlebum]

Another trick is to pack the tap with thick grease the shavings stick to the grease on the tap, then if need be just stick the straw of a can of brake clean right to the bottom of the hole and flush it out.