Hellicoil Threading

[Kiwi_Roy]

One of the 6mm x 1mm pitch screws holding the rocker cover on stripped the thread and fell out.

I have always been aware of hellicoils but never used one. The PO included 2 or 3 with the spare parts.

Can I use a 7mm x 1mm tap or do I have to buy a special tap?

 

Thanks

Roy

[GuzziMoto]

I think it will be an 8mm tap for a 6mm insert.

I have used 6mm inserts in 8mm threads to down size to a smaller bolt.

I believe it is a 2mm larger tap then the finished threads.

[belfastguzzi]

One of the 6mm x 1mm pitch screws holding the rocker cover on stripped the thread and fell out.

I have always been aware of hellicoils but never used one. The PO included 2 or 3 with the spare parts.

Can I use a 7mm x 1mm tap or do I have to buy a special tap?

 

Thanks

Roy

I need to do this on the Griso head too, as the Service Agent stripped one of the rocker bolt threads.

What do you mean by PO and spare parts?

 

As I understand it, the problem about fitting Helicoils is the expense of the fitting tool: so you need to find someone else who can do it, or pay a high cost to buy a tool for one or two uses.

[GuzziMoto]

Helicoils are inexpensive and easy to install in my experience. There are cheaper knock-off versions if the real thing is too much money, but you pay your money and take your chances. I have installed Helicoils with and without the special tool. It makes it easier but it is doable without it.

In my experience helicoils are your friend.

[Kiwi_Roy]

I think it will be an 8mm tap for a 6mm insert.

I have used 6mm inserts in 8mm threads to down size to a smaller bolt.

I believe it is a 2mm larger tap then the finished threads.

That's what I thought at first, I measured the hellicoil and it's just under 8mm diameter but if I look for a suitable tap the 8mm seem to be all 1.5mm thread pitch, that would force the 6mm to be the same, not 1mm. The 7 mm tap has 1mm pitch

Perhaps I need to find a local distrubutor with the correct tap.

Update

I just got off the phone with a local autoparts store, they sell the kit c/w special tap, one coil size per kit, I'm sure it's cheaper south of 49° but it's worth $40 to get it fixed and 6mm is such a common size on the bike it should come in handy.

I gather that the hellicoil fix makes it stronger than original which makes sense.

 

Thanks

Roy

[GuzziMoto]

It may be stronger, but it is definitely more durable for bolts that are frequently removed and installed.

[raz]

That's what I thought at first, I measured the hellicoil and it's just under 8mm diameter but if I look for a suitable tap the 8mm seem to be all 1.5mm thread pitch, that would force the 6mm to be the same, not 1mm. The 7 mm tap has 1mm pitch

M8 x 1 is not the "standard M8" but it is the "standard fine thread", I can get a tap at any good hardware store here.

 

When I found out my cylinder studs ate the block, I threw the towel and bought a US$500 full set of helicoils (though they are called Recoil iirc, from Oz) and now a year later or two, I have forgotten the expense and it's DAMN GOOD to have that kit ready for emergencies!

 

I seem to remember the M6 insert taps are neither M7 or M8 but M7-point-something ... I'll have a look tomorrow.

[gstallons]

One of the 6mm x 1mm pitch screws holding the rocker cover on stripped the thread and fell out.

I have always been aware of hellicoils but never used one. The PO included 2 or 3 with the spare parts.

Can I use a 7mm x 1mm tap or do I have to buy a special tap?

 

Thanks

Roy

 

 

Roy,

Go to a GOOD auto parts store & purchas a Heli-Coil brand thread repair kit. It will come with the appropriate tap,insert installer and inserts. The only you have to provide is the drill bit (the size wil be stamped on the package) and patience. If you have to, try on a piece of metal two or three times before doing it on your bike.

[Kiwi_Roy]

 

 

 

Roy,

Go to a GOOD auto parts store & purchas a Heli-Coil brand thread repair kit. It will come with the appropriate tap,insert installer and inserts. The only you have to provide is the drill bit (the size wil be stamped on the package) and patience. If you have to, try on a piece of metal two or three times before doing it on your bike.

 

Yes, I was quoted less than $40 for genuine hellicoil 6mm kit c/w tap.

It seems they stock a seperate kit for each size which is good since most on the Guzzi are 6mm

 

Thanks for all your help

 

Update:

I picked up a kit today it comes with a special tap, an insertion tool, Insertion guide instructions and 12 stainless steel inserts, just enough change out of $50 for a coffee and a bagel.

Actually Lordco list price is $74.47 but they sold it to me for $37 + tax $41.44

 

The little inserts have a tang that engages with the insert tool, apparently you can snap this off once it's installed.

What doesn't come with the kit is 1/4 drill and a punch for snapping the tang off but no problem there, just need a piece of rod with a square end

 

Roy

[gstallons]

This kit should have a min. of 5 inserts....... does it? These are available seperately too.

[gstallons]

Here is a good video on the subject.........enjoy the Tenn. drawl.

[emry]

Not to chime in late or anything but I normally prefer the Timesert brand, although it does depend on the install location. Timeserts use a solid insert in place of the spring with a small lip at that fits into a groove that must be cut in the repair site. Much better luck with them in areas where bolts are removed on a normal basis, helicoils can come out too easily and do not provide a very good taper at the OE's bolts insertion point. But either can work well if the installation is done carefully.

[gstallons]

I own a Timesert kit that I use for Ford spark plug repairs. VERY good and VERY pricey.

[Kiwi_Roy]

Here is a good video on the subject.........enjoy the Tenn. drawl.

 

The video does a good job of showing how simple it is.

The tricky part is to get the drill nice and square with the head, it would be very easy to mess up, if I do any

others I will make some sort of mandrel or at least mount a square under an adjacent bolt as a guide.

I noticed at least one other screw hole with a hellicoil insert, the PO must have stripped a few, I read somewhere

that the socket head screws make it too easy to over tighten.

 

Thanks for all the good advice.

 

Roy

[Kiwi_Roy]

Not to chime in late or anything but I normally prefer the Timesert brand, although it does depend on the install location. Timeserts use a solid insert in place of the spring with a small lip at that fits into a groove that must be cut in the repair site. Much better luck with them in areas where bolts are removed on a normal basis, helicoils can come out too easily and do not provide a very good taper at the OE's bolts insertion point. But either can work well if the installation is done carefully.

I thought about using a tiny drop of locktite on the outer thread but didn't in the end, however I was careful to make sure the bolt I used in that hole was not stainless.