Primary damage...your thoughts please!

[bryantch]

i was installing the heavy hitters i got from matt today and all was going fine until i snapped one of the primary cover bolts off. no big deal, just use a screw extractor...broke it... (i hate the new, made in china, craftsmen tools...)

so anyhow, several frustrating hours later, i got the screw extractor out, but have destroyed the bolt hole.

my assumption would be that i just need a new one. i figure that helicoiling the primary is a bad idea because of balance? and so is just leaving that bolt out?

not too bad for my first attempt at installing a clutch kit!!!

tomorrow another first...working on carbs - installing ecp kit...ok let me guess, smoking is not recommended while removing the float bowls. :shock:

 

[LazyBastard]

Helicoil might not be the best way to do it. Ideally, you would bring it to someone with a mig or tig welder to fill in the hole, then drill and tap. Alternative is to use a really good epoxy with suspended aluminum, fill the hole with that, drill, and tap.

 

[bryantch]

would it need to be balanced again? if so where would i get that done?

thanks
ian

 

[LazyBastard]

If you fill it in, drill it to the same depth, and tap it, the balance will be so close that you couldn't measure the difference from original. The epoxy should be extremely close (so as not to make any difference), filling it in with aluminum weld will be *exact*. Helicoils are steel, so they'll throw off the balance a bit, plus you will be thinning out the wall around it.

 

[nhrxrider]

I used to be a machinist (10 years) and I second what LB said, exactly! I haven't had a clutch apart...so I don't know how much pressure is put on that screw...but if its not too much the epoxy would work well. If you know a good welder who can do aluminum, that would be the best route.

Jim

 

[local 25]

bryantch,i have used a product called JB weld, mostly all autzone ,pep boys etc. sell it. they sell several different types.use the kind that comes in a 2 part putty.it is sold in a round tube that is about the size of a roll of quarters. i also had to fill in a hole and then drill and tap it 1/4-20 on my motorhome.i was truly amazed at how hard that it dried,and in less than an hour.it really took well to the threads that i have put in it.as far as the weight of the subtance im not sure ,but it it does some weight to it. good luck

 

[VMX]

you could use a hei-coil you would only use a 1/4" one so the weight difference wouldn`t be enough to notice or you could do all 6 then they would be the same

 

[Snowman269]

You didn’t post a pic, but I would go the JB Weld route. Drill & tap. Welding may not be the best answer because of the heat changing the hardness of the metal. I’m not a metallurgist, but I’d hate to hear about your clutch coming apart on you.

I took a dirtbike on trade where the guy had JB welded the drain bolt in. You couldn’t tell from the outside. As I was amazed how tight the bolt was, then the case cracked. Once rebuilding the motor with a new case halve, you couldn’t separate the JB weld from the old case or the bolt. It was just like a weld. Amazing stuff!

 

[RedRX1]

I agree, the JB Weld is the safest route. I would also watch how tight the bolts are torqued to. either use a torque wrench or a 1/4" drive socket turned hand tight with your hand held over the socket end of the wrench.

 

[Bob Miller]

Another product that you could use is called "LIQUID METAL". This product is not mixed and squeezes out of a tube! This stuff is also truly amazing!

Another alternative is this: Determine what is the next size up bolt in SAE (american fine thread) and usually you can run that particular tap into the existing hole without drilling because it is only slightly larger, and you will get some new threads into it, and this will not change the balance at all!

I have done this also! If you tell me what size bolt it is, I can tell you what size you would go to! 8)

 

[bryantch]

thanks to all the replies! I just bought some jb weld and will try that route...if it doesnt work i will probably just get another primary...will let you guys know how it turns out! looks like i will have some time to do the work either way...rain melted the 20"+ inches of snow we had here last week I hoped some snow would be left so I could try out the ecp/clutching and new ripsaw and 136 MP extension kit I got from matt (great guy)

Again thanks to all...
Ian