Stripped screw hole

[tedfeast]

Well inwas rounding the corner on finishing my head gasket replacement, went to install the intake manifold bolts and turns out that one of the holes in the rebuilt heads i bought is stripped.
Doesn't even bite.
So, what are my options?
Larger diameter bolt
Drill and tap
Thanks in advance for your time and advice.

[tlbranth]

I like helicoils.

[Lucien Harpress]

Check out time-serts too. A bit more involved than helicoils, but (to me) make a bit more sense.

[cfairweather]

Time-Serts are expensive, but I believe they are the best.

[tedfeast]

the intake manifold bolt are an M6 ?
parts list says 6x32.

[robin1731]

32 is the length. 32mm. I use helicoils all the time for bolts that size. Smaller sizes, like for carb bowls, I do use time-serts. But helicoils are fine for 6mm.

[tedfeast]

yeah i get the 32 mm.
i was just checking about the diameter.
the parts fiche over at partzilla says they're a 6x32.
so a M6 thread x32?
just making sure i get the right helicoil.
trying to avoid any more unforeseen issues.

[gltriker]

Here's a link to help understand the criteria utilized to identify a threaded metric fastener.
https://www.google.com/search?q=Metric+ ... 2&dpr=1.25

Measuring metric thread pitch is confusing at first. Instead of counting actual threads per inch, metric pitch is measured as the distance between 2 adjacent threads, in millimeters. Small diameter metric fasteners may have a pitch measurement of 0.7 mm.
0.7 mm is considered to be a Fine thread.
If I remember correctly, the machine screw that is removed from the synchronizer fitting hole in order to install a synchronizer hose barb fitting is designated to be measured as M5 x 0.7. I don't know what its length measurement is off hand.

I looked in an on-line OEM GL1000 Parts Catalog and found the same incomplete dimension information for the fastener you are studying. Yes. The metric diameter is called out, and the fastener length. The thread pitch number is indeed missing.

Obtain a metric thread pitch gauge to save your sanity .

This item is very similar to the thread gauge that I finally broke down and purchased off Amazon.
https://www.amazon.com/Stainlesstown-Bo ... 0UMK&psc=1

[Matthew]

Hi, having grown up with the metric system in my family's Kawasaki and Honda dealership (Australia) I can confirm that the standard 6mm thread pitch is 6 x 1 (one thread per MM) or commonly known as simply "M6". If you asked for a M6 x 32 screw you should be given a 6 x 1 pitch screw that is 32mm long. This is probably the most common thread size on Japanese and European bikes, closely followed by M8 (8 x 1.25), M5 (5 x 0.8), M10 (10 x 1.5), M12 (12 x 1.75) and M14 (14 x 2). There are other thread pitches available but these are the common ones.
Does that help?
I know its a controversial subject but in my opinion a helicoil in that stripped M6 hole for the intake manifold will be a good fix and will serve you well. I have used many of them over the years and not had a failure. Just for reference I have never used a time cert, so I'm not going to argue either way. Just sharing what works for me.
Cheers,
Matthew.

[Matthew]

0.7 mm is considered to be a Fine thread.
If I remember correctly, the machine screw that is removed from the synchronizer fitting hole in order to install a synchronizer hose barb fitting is designated to be measured as M5 x 0.7. I don't know what its length measurement is off hand.

Hi mate,

Sorry to hijack the thread for a bit...

I'm thinking that the barb fitting is M5 (5 x 0.8), that is considered "normal" for that size metric screw but on a larger diameter screw it would be a "fine" thread in the metric world.

Sorry, not wanting to point out something wrong, rather just trying to help those that are possibly not familiar with the metric thread system. I believe its quite a simple system, but I have lived with it for close to 50 years. YMMV

Hijack over now.

Cheers,

Matthew.

[gltriker]

0.7 mm is considered to be a Fine thread.
If I remember correctly, the machine screw that is removed from the synchronizer fitting hole in order to install a synchronizer hose barb fitting is designated to be measured as M5 x 0.7. I don't know what its length measurement is off hand.

Hi mate,

Sorry to hijack the thread for a bit...

I'm thinking that the barb fitting is M5 (5 x 0.8), that is considered "normal" for that size metric screw but on a larger diameter screw it would be a "fine" thread in the metric world.

Sorry, not wanting to point out something wrong, rather just trying to help those that are possibly not familiar with the metric thread system. I believe its quite a simple system, but I have lived with it for close to 50 years. YMMV

Hijack over now.

Cheers,

Matthew.

Perfect! I didn't remember correctly, after all.

[tedfeast]

Thanks for all the input everyone!
Just trying to make sure and get the right stuff.
I went ahead and ordered a complete set of helicoils for varying sizes as well as a male/female thread size gauge.
Very frustrating when I'm so close to finish the job and find out theres a stripped hole in an otherwise freshly rebuilt cylinder head!.
I think I'll get through though..

[6adan]

tedfeast, where did you order the helicoils from? I find myself with the same problem with a 1100 I am working on.

[robin1731]

tedfeast, where did you order the helicoils from? I find myself with the same problem with a 1100 I am working on.

Check your local hardware store or auto parts store.

[pidjones]

Also Amazon.