1100 ex, cam cap thread repair

[slideplayer]

Hi peeps, just discovered a thread stripped on one of the cam retaining caps, need to get a helicoil kit to repair it. Any info on what the thread size is, or where i can get the kit to fix it ? Many thanks.

[Steve]

The threads are M6 x 1.0.

Due to your location, I don't have any clue where to find repair kits.
Do you have a local auto parts store or hardware supplier?
If not, check your local version of eBay.

.

[sharpy]

If its the hole with a dowel in it. one way to do it is the tread a 3/16 thread into it and use the corresponding bolt. Pretty sire it was 3/16th. been so long ago. Update. seems its not 3/16th bolt, but 1/4 unc in 6mm hole . I said my memory sucked

[sharpy]

Due to a private message i received regarding my post above..... "Sharpy, if you don't know or unsure what you're talking about why respond? There is no 3/16 screw thread, not in American standard anyway... All your doing is confusing people that don't know" Seems i dont know jack squat or am a lair.
5mm
Decimal Equivalent 0.1968’’
Closest Imperial Size 3/16
Decimal Equivalent 0.1875’’

If 6mm thread you just find next size. And i was revering to the holes where the dowels sit as its pretty hard to put inserts in them as most times the drill size is bigger than the dowel size. Seen it done many many times and its a easy way to fix that issue, if it doesnt work then then always the option of going the insert way.

There is a whole wide world outside of america and yes people do know about stuff aswell. Shock horror Like many. i put in a reply as i know it works and my reply is a guide/option that does work. Its up the the original poster to pick through every ones options and try what they think is best. Far as i can see it pretty bad taste to PM someone for trying to help, just because you have never heard of that way to do things. I am not a friggn idiot, so if you treat me that way you have lost all my respect. No names have been mentioned as i think i have more class than that.
Edited... The 3/16th thread is just a touch bigger that original thread and is only a easy fix. Yes Personally i would do the insert way but if i recall where the dowels sit doing inserts make the dowel whole bigger. Still that problem is fixable. And there all only suggestions that do work.

[posplayr]

My $0.02 having stripped many cap screw threads, is to just get the proper helical and make a permanent repair.

In fact unless you are on a tight budget, I would buy new cap screw bolts. I was amazed at how easy it is to twist off the tops of the steel bolts in an aluminum head (and yes using a calibrated torque wrench).

[JTGS850GL]

My $0.02 having stripped many cap screw threads, is to just get the proper helical and make a permanent repair.

In fact unless you are on a tight budget, I would buy new cap screw bolts. I was amazed at how easy it is to twist off the tops of the steel bolts in an aluminum head (and yes using a calibrated torque wrench).

The problem I've seen is that previous owners didn't use a torque wrench and have weakened to screws so they no longer can be torqued to standard. Replacing the cap screws would be a good option IMHO.

In response to the poster that suggested using standard thread posts.... I would consider the a proper Helicoil as the better solution to the problem. More perminent and the next owner wont be making fun of me for doing it.

And no, I'm not the one that PM him.

[posplayr]

The problem I've seen is that previous owners didn't use a torque wrench and have weakened to screws so they no longer can be torqued to standard. Replacing the cap screws would be a good option IMHO.

In response to the poster that suggested using standard thread posts.... I would consider the a proper Helicoil as the better solution to the problem. More perminent and the next owner wont be making fun of me for doing it.

And no, I'm not the one that PM him.

What was shocking was that the bolts would twist with little effort. It is possible that the head had been heli coiled but I was doing everything with an HF calibrated torque wrench.

I did a thread on torque wrench calibration long ago, but it doesn't come up in a search. I found this instead.

[sharpy]

Other problem is people not using the right torque wrench for that application. Using one thats intended for axle nuts is asking for trouble when using it for cam cap bolts and similar.

[GregT]

I've done a lot of them over the years. I keep a brass bush 8mmOD X 8mm long which is a slip fit over the helicoiling tool in with my 6mm helicoils.
After cleaning up the stripped hole with a 6mm drill, tap for the insert. Blow all the crud out. Then put the helicoil on the tool with the spacer above it, under the adjustable collar. Insert helicoil. Job done.

The dowel holes are 8mm so the bush should be a tad under 8mm OD.

This also works on sidecover threads where there's a dowel recess too.

[slideplayer]

Hi peeps, thanks for the replies, so i need a 6mm drill, but what helicoil and tap do i need to buy to use the original size bolt ? Many thanks.

[JTGS850GL]

Hi peeps, thanks for the replies, so i need a 6mm drill, but what helicoil and tap do i need to buy to use the original size bolt ? Many thanks.

Steve actually answered the question. The original screws are 6mm x 1mm thread pitch. Here's a link to a kit from O'Reilly's Auto Parts that gives the specs of the components contained in the kit. It says to use a 1/4" drill bit.

[Cipher]

hmmmmm. Yes well whether you use a torque wrench or not threads will eventually fail. Work hardening from repeated tightening.

[posplayr]

hmmmmm. Yes well whether you use a torque wrench or not threads will eventually fail. Work hardening from repeated tightening.

What was amazing to me is that I twisted off three different bolts without stripping the threads on a GS1100E 16V head while using a torque wrench. I would have expected the threads t ogo long before the bolts twisted off.

I did no tactually fully twist off the bolt heads as I could tell that I was not getting any more torque, and back off removing the bolts to see what was happening.

This is a long story about a supposed new head of ebay. It was glass peened but not new.

[Cipher]

I had to swap a head in my truck years ago due to an overheating episode that caused two valves to burn and cracks to appear in the webbing between the intake and exhaust runners of the inboard pistons.

The innermost head bolts on the exhaust side were seriously fatigued and weakened when I attempted to reinstall I got the nauseating familiar feel of the bolt twisting. I managed to reverse it and went to the dealer for two new bolts. God what a day that was.

The uses of hard steel in softer aluminum cam caps is accountant driven engineering. They don't chrome those to be pretty I imagine they do it to reduce galling. Had they come with inserts from the factory a lot of misery would have been saved. But then the engineers never expected and the accountants never wanted a bike to last 30 - 40 years in service.

[posplayr]

I had to swap a head in my truck years ago due to an overheating episode that caused two valves to burn and cracks to appear in the webbing between the intake and exhaust runners of the inboard pistons.

The innermost head bolts on the exhaust side were seriously fatigued and weakened when I attempted to reinstall I got the nauseating familiar feel of the bolt twisting. I managed to reverse it and went to the dealer for two new bolts. God what a day that was.

The uses of hard steel in softer aluminum cam caps is accountant driven engineering. They don't chrome those to be pretty I imagine they do it to reduce galling. Had they come with inserts from the factory a lot of misery would have been saved. But then the engineers never expected and the accountants never wanted a bike to last 30 - 40 years in service.

This was not gauling, the head had been completely disassembled and inspected and I was re assembling.