Kips cover 5mm stripped... Heli Coil or tap?

[reepicheep]

My kips cover has two of the three bolts stripped out, and I was wondering if anyone has done the math before...

The two obvious solutions are
1) Tap it out to a 6mm hole and use a 6mm bolt and be done with it.
2) Use a 5mm heli coil and repair it back to the original bolts.

My concern with both of these is the amount of material it will remove. There isn't a lot of margin there for the top part of the bolt.

Frankly, I suspect either will work, but I might as well start with the less invasive of the two.

So which removes more material? Going to a 6mm thread, or going to a heli coil (which is probably at least 6mm itself to make a 5mm inner hole)?

Originally, I was going to go with the heli coil to "do it right", but those suckers are hard to find that small, and expensive, and as I think about it I'm guessing that if I do tap it to 6mm, and that pulls out for some reason, I could even then go to the heli coil back to 5mm.

I'll be happy to look it up and I'll be sure and post the conclusion here, but I thought I would ask in case somebody else already went down that road.

 

[reepicheep]

Cool! That was easy. Don't take this as gospel, but I am pretty sure these are right.

For tapping:

5mm fine thread needs a 4.5mm hole.
6mm fine thread needs a 5.5mm hole.

For Helicoils:

5mm fine thread needs a 5.2mm hole
6mm fine thread needs a 6.2mm hole

So the Heli Coil will actually remove less material then re-tapping would remove, but not by much. I think Pep-Boys had the smaller Heli-Coils for a not so extortive price (I've paid as much as $50 for those stupid kits)... I'll check.

I'll have to check the service honda site and make sure those are really M5 fine bolts as well, now that I think about it...

Thanks to all the previous owners of the various ebay and craigslist bikes I have bought, you have lead me to gather quite an extensive heli coil collection. :bang:

 

[reepicheep]

Actually, that works out well for the two step failure process :)

1) Strip out factory 5mm bolt.
2) Drill hole to 5.2mm and retap for heli coil.
3) Strip out heli coil (which I am assuming creates a 5.4mm hole)
4) Drill to 5.5mm and retap to 6mm bolt.

Repeat until you run out of head material ;)

On the other hand, if the 5mm heli coil is unobtanium, or if it is $50 or something, going straight to the 6mm bolt only removes an additional .3mm of material... so that option would not be crazy either.

 

[ronnie l]

You could also use a thread repair kit. I think the one I bought was from Loctite. I used it on a belt tensioner on my wife's car.

The stuff consists on a thick glue like substance that you would fill the stripped hole with. It also has a release agent that you paint the bolt with.
You screw the bolt into the hole and after a few hours you can back it out. It reforms the threads. It worked very well for me. :nod:

 

[liven07]

Heli coils are supposed to be alot stronger then just a taped threads. Aluminum is not very strong and would just end up striping again, it always seems like taped threads are never as strong as the original threads anyway. I would definitely go with the heli coils.

 

[mudpack]

You could also use a thread repair kit. I think the one I bought was from Loctite.

Even though I am a natural skeptic, I have used these thread restorer kits myself in aluminum...and they work, just as ronnie said.
I would use one of these kits(they aren't very costly at all) before I tried drilling and tapping for a helicoil or a larger bolt.
Unless you have had extensive experience in drilling and tapping, the job will probably yield weak threads. (poor quality work is the reason a lot of re-tap jobs are so weak)

Good luck

 

[ronnie l]

Even though I am a natural skeptic, I have used these thread restorer kits myself in aluminum...and they work, just as ronnie said.
I would use one of these kits(they aren't very costly at all) before I tried drilling and tapping for a helicoil or a larger bolt.
Unless you have had extensive experience in drilling and tapping, the job will probably yield weak threads. (poor quality work is the reason a lot of re-tap jobs are so weak)

Good luck

Agreed, also since the bolt in not under any stress the repair kit should be fine.

 

[reepicheep]

I'll see if I can scare one of those glue kits... not much to loose trying it, and this is a low stress application.

5mm thread kits are rare as hens teeth... nobody local stocks them, and mail order is $30. Not the end of the world, but a lot of money and trouble just to hold that cover on.

I'll try and look at the location of the hole tonight and see if there is enough material to just go to a 6mm. I have taps for that already, and even have heli coils for that in the drawer already also. So if there is enough material there to (worst case) bump up to a 6mm heli coil, then it seems stupid to spend $30 and wait a week for shipping for the 5mm part. I can live with the .02 grams extra weight of the bigger bolts...

 

[ronnie l]

Sorry it was permatex thread repair
http://www.permatex.com/products/Au...ad_repair/Permatex_Stripped_Thread_Repair.htm

 

[liven07]

There are 2 different kinds of permatex thread repair, one is removable that is made to lock good threads and will not hold a striped bolt and the other is permanent. I have not used the permanent but I heard you need a drill to remove the bolt after using it.

 

[ronnie l]

There are 2 different kinds of permatex thread repair, one is removable that is made to lock good threads and will not hold a striped bolt and the other is permanent. I have not used the permanent but I heard you need a drill to remove the bolt after using it.

You are talking about two different products. There is a threadlocker or Loctite type product, which is available in different strengths this is totally different than the thread repair kit. One is to keep nuts and bolts from loosening and what I spoke of is a actual thread repair kit.

 

[liven07]

I never heard of that, just the permatex. Sounds cool if it works good because I got a couple of jobs. How good does it hold?

 

[mudpack]

The thread restorer kit I used allowed full torque on the 6mm bolt.
There aren't many products that deliver as advertised. This thread restorer kit is one of the few that actually work, and that I can recommend unequivocally.

Mud

 

[reepicheep]

I'll try and scare it up and post how it works on the KIPS chamber cover. Thanks again Mudpack and others...

 

[reepicheep]

Arrghhh. Other reviews of the product look good. Price looks to be between $10 and $20 (not cheap, but reasonable, especially if I have some left over for future disasters)...

But can you find it retail anywhere? I tried all my local places, and can't seem to find it stocked... Fastenal lists it in their catalog, but does not stock it locally, and even online they list a multi week lead time...

Hrrrmph. Seems like a nice product thats really hard to find.

 

[mudpack]

As I recall, I got it at Autozone.
Mud

 

[reepicheep]

Autozone did in fact have the permetex stuff on the shelf (in spite of their web sites assertions to the contrary).

I tried using it last night, and it did not work. I'm wondering if the batch I got has been sitting there on the shelf for decade or something. Also, where it said "cut the tips off the syringes", I just pulled the caps off and they were open, not sealed. The packaging looked intact though.

Anyway, I followed the instructions to the letter, let it sit for 3 times the recommended 30 minute interval, and the bolts stripped back out at about 3 nm of torque (just over hand snug).

Looking back at the leftover goo on the cardboard, even after 90 minutes, it hadn't set either. Even this morning, it still was soft.

So I think the stuff could work, but I just got a bad batch. So maybe there is a lesson there about mail ordering from a company that moves a lot of product so you get a fresh batch, rather then getting it locally off the shelf where they may only get one package a decade.

Anyway, I got tired of fussing with it, so (for better or worse) I just JB-Welded some 5mm grade 8 threaded rods in the two stripped holes to make them studs. Now the wear surfaces are steel on steel, rather then soft aluminum. If the JB Weld pulls out over time (it might, but that stuff usually sticks pretty good), then I'll order the $30 helicoil kits and go from there.

So for now, the JBWelded (not JB Quick, its not as strong) stud is a $3 fix that may very well last the life of the bike. If this was a more demanding job then just holding on that empty cover with bolts torqued to 8 NM, I'd have gone straight to the heli-coil.

I'll fess up here if it fails and I end up spending 30 minutes with a tungsten carbide dremel bit cutting out pieces of those threaded rods and old JB Weld. :)

 

[sr5bidder]

I bought the m6x1.0 helicoil kit and it has come in handy many many times

 

[reepicheep]

Yup! I have one in the drawer as well, and highly recommend it. Problem here is that this is a 5mm bolt... and the 5mm heli coils are a lot harder to come by. The hole also has very little support around it, its a raised area of the cylinder casting. So I will use a 5mm heli-coil it if I must.

I thought about tapping it out to 6mm, but I don't want to run out of aluminum... and if that 6mm strips, then the 6mm heli coil needs something like a 6.2mm hole.

I wish Kawasaki had just stuck to 6mm across the board for simplicities sake. Seems silly to have 3 holes in the motor that are 5mm when everything else is 6mm...

 

[sr5bidder]

oh did not realize they drifted away for those, but like I said most all bolts on the jap bikes are the m6

 

[reepicheep]

Two days later, the permatex stuff left over on the cardboard still hasn't cured, so clearly I got a bad batch. YMMV. I still have the tubes, maybe I'll try and mix up more tonight (being insanely careful to avoid contaminating anything and to get the ratios right) and see if its any better, just out of curiousity.

For the JB Welded in studs, interestingly, only one of the two held. The other pulled out. I'm hoping it was because there was still leftover goo from the failed permetex repair, so I drilled the hole out to a clean 5mm (if I do the heli coil, it needs a 5.2mm hole) and tried jbwelding it again. We will see tonight if that holds now. If not, I'll order the heli coil.

Don't strip or shear that rear most kips cover bolt. There isn't much spare material anchoring it in there, and the bolt an odd size, so its a headache to repair.

(For the record, it takes a 5mm .8 pitch heli coil... which are readily available online for about $30 but hard to scare up locally...)

 

[mudpack]

Two days later, the permatex stuff left over on the cardboard still hasn't cured, so clearly I got a bad batch.

For the JB Welded in studs, interestingly, only one of the two held. The other pulled out. I'm hoping it was because there was still leftover goo from the failed permetex repair,

I agree with you on both subjects. The kit I bought had sealed tubes of epoxy.

Mud

 

[porterdog]

...so (for better or worse) I just JB-Welded some 5mm grade 8 threaded rods in the two stripped holes to make them studs.

Good idea! Hope the second go 'round works out proper.

 

[reepicheep]

Well, the saga has come to an end.

The JB Welded posts (both of them) happily pulled right out after a couple days of sitting and less then 9 NM of torque.

The 5mm heli coil kit (M5 X .8) can be found online (toolsquik in my case, but others have them). It was Perma Coil, not Heli Coil, but i have used both and if anything the Perma Coil's are better. It was $29 to my door, I ordered it on Monday and had it by Wed.

It took about 15 minutes going slow and carefully to install the two stripped holes, the third one (furthest forward) was still holding with the original threads.

It torqued up great and held fine.

So my advice to anyone else who has this problem? Mail order and jump straight to the 5mm heli coil, don't putz with intermediate steps.