Stripped threads in carb body.

[rebar]

I went to check needle clip position on my keihin carbs and found one of the M4 top cover screws missing. I removed another to check the empty hole and the screw went all the way in without turning.:bang head: stripped.

I dont think there is enough material to install a helicoil.

What other options are there other than the obvious?

 

[davidon]

I had a similar problem and just used a slightly longer screw..it seems to be working (like 2 or 3 mm longer)

 

[rebar]

Thanks. I will try that first and hope. I measured the hole and its at least 3mm deeper than the screw.

 

[satariel666]

Upgrade it to M5 thread. Do not bore the hole, just tap it, M4 stripped size is good for new M5 tap.

Then take the 5mm drill and use it to drill the hole in the cover to make a correct size for M5 bolt.

Another option is Helicoil.

 

[rebar]

Upgrade it to M5 thread. Do not bore the hole, just tap it, M4 stripped size is good for new M5 tap.

I like your approach since I noticed the other 7 threads feel loose and fragile Przemek.

Looks like I will be learning how to disassemble these carbs before I thought.

 

[rebar]

I had a similar problem and just used a slightly longer screw..it seems to be working (like 2 or 3 mm longer)

That did it Davidon. Im only catching 3 turns of thread though. I wonder if I can drill and tap M4 deeper..

Upgrade it to M5 thread. Do not bore the hole, just tap it, M4 stripped size is good for new M5 tap.

Then take the 5mm drill and use it to drill the hole in the cover to make a correct size for M5 bolt.

Another option is Helicoil.

Przemek. Did you install M5 socket/allen head screws in keihin FCR's for the top covers?
I bought a few M5's but the allen head looks to big. Meaning the M4 allen heads barely clear obstructions on the top cap which I dont think the M5's will clear.

And same for the M4 helicoil.. For a FCR top cover?

Or are you just listing methods to fix stripped threads given enough material?

http://www.timesert.com/html/usefultools.html
These are different
http://www.gizmology.net/nutsbolts.htm
thread info..

 

[rebar]

This stuff should do the trick. :eusa_dance:
Loctite

Form-A-Thread

Stripped Thread Repair Kit​

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http://www.midwayusa.com/midwayusa/StaticPages/pdf/instructions/Loctite_stripped_threads.pdf
​