Suggestions please

[alke46]

I am getting ready to synchronize the carbs on my 1000E and one of the little ports that the carbtune hoses attach to has been stripped from a PO. Any ideas on how to repair this stripped thread?

I have a heli coil but not the special tool to install it. I just checked locally and the price to get the correct tool to insert the heli coil is going to cost me around $50.

I am having a hard time trying to justify spending 50 bux for a one time use tool.

Can I just drill out the hole to a larger size then tap it with the correct sized tap and put the screw into the heli coil and insert it with some thread lock on it?

Thanks in advance.

[Steve]

Heli-coils are a unique-sized thread on the outside. They don't really have numbers published, they just provide the proper tap and say "here, use THIS".

The installation tool is special because it pulls the coil in from the end, which pulls it into a slightly tighter diameter. When you break off the tang (you will want to have the carbs off while you do that), the coil relaxes a bit and expands into place, which locks it there. There is really no other way to install the coil.

Let me see if I have a 5mm kit. If I do, I'll let you borrow it to do your install.

.

[greg78gs750]

cut a slot in the end of a small bolt? no real magic to the special tool, as far as i can tell....

[Steve]

cut a slot in the end of a small bolt? no real magic to the special tool, as far as i can tell....

The "small bolt" is a specially-undersized bolt that allows the coil to shrink in just a bit. Unless you have an M4.5x0.5 bolt in your pocket, he needs the proper tool.

.

[Sandy]

If you can't come up with a reasonable fix can you just tap it to 6mm and use a 6mm adaptor.

[alke46]

If you can't come up with a reasonable fix can you just tap it to 6mm and use a 6mm adaptor.

I guess this might be my best bet as there are some 6mm adapters in the carbtune package and I have a 6mm tap on hand already.
Now I need to drill a new hole of either 5mm or 3/16 in. and tap with the 6mm tap and get a 6mm screw. Way cheaper than that 50 dollar special tool to install a heli coil.

[SVSooke]

Heli-coils are a unique-sized thread on the outside. They don't really have numbers published, they just provide the proper tap and say "here, use THIS".

The installation tool is special because it pulls the coil in from the end, which pulls it into a slightly tighter diameter. When you break off the tang (you will want to have the carbs off while you do that), the coil relaxes a bit and expands into place, which locks it there. There is really no other way to install the coil.

Let me see if I have a 5mm kit. If I do, I'll let you borrow it to do your install.

.

Are you sure they are special sized taps?I have a knock off kit and had to coil an 1 oversize bolt that some PO put in place of the 6 mm exhaust stud on my 82 GPz750. The coil went right in and a 6 mm bolt now fits.An age ago a local shop did two coils for a stripped exhaust thread on my 81 GS650E (RIP).

[Steve]

Let me see if I have a 5mm kit. If I do, I'll let you borrow it to do your install.

Sorry, I do not have a 5mm Heli-coil kit.

Are you sure they are special sized taps?I have a knock off kit and had to coil an 1 oversize bolt that some PO put in place of the 6 mm exhaust stud on my 82 GPz750. The coil went right in and a 6 mm bolt now fits.An age ago a local shop did two coils for a stripped exhaust thread on my 81 GS650E (RIP).

Did they install a 6mm kit or did they just use the tap for the 5mm kit and not install the coil?

I am under the impression that the TAPS are a unique size to Heli-coil and maybe to anyone else that uses a similar system. For example, the M5x0.8 kit that is necessary for alke46's bike will have instructions to use a certain size drill, then their special tap. That tap is what is necessary to put threads into the hole that was just drilled that will allow the coil to be inserted to bring it back to M5x0.8 specs. I have no idea if that tap is 5.8mm wide, 6mm wide, 6.3mm wide or what, but for sure, it's what is necessary for their coil.

Standard thread pitches for M5 and M6 are different, so I am guessing that you might have had an M6 kit installed.

.

[SVSooke]

What the shop did I have no idea but it worked even if it was a bodge.A Helicoil brand kit may be different but my kit the tap just ran up the 8 mm threads and the coil made them 6.Yes I'm surprised it worked.

[Steve]

That's even more puzzling. M8 comes in 1.25, 1.50 and 1.75 pitches, but the M6 is 1.0, 0.8 and 0.5.

No way a simple M8 tap will allow an M6 bolt to thread in. As stated before, the larger size for the Heli-coil taps might approach an M8 size, but the thread pitch will be for the smaller bolt for which the coil is sized.

.

[AMK]

You are correct Steve, Helicoil taps are special sizes but the pitch is the same.

[DohcBikes]

Heli-coils suck. There are several insert kits that are superior.

[Steve]

Please feel free to elaborate.

True, Heli-coils might not be the best, but they are usually much easier to obtain and perfectly acceptable for the job at hand.

.

[AMK]

I will elaborate. Helicoils are good for more permanent fastening. I personally don't like them either.
In this instance I would prefer tapping to M6 and use Helicoils as last resort.

[alke46]

I am going to tap the hole for 6mm and just have 3 of one size and 1 that is 6mm instead of 5mm.