helicoils came out

[Guest]

1981 gs1000g
Hi all. I had to pull the exhaust cam to replace tach gear. There were helicoils that came out of the holes that you bolt the cam caps to. They were placed by po. One of them came out in tiny pieces. It appears there may be some helicoil left in the bottom of each hole.
I can torque the bolts to 7 pounds without the cam cap in place. The bolts go in about 3mm deeper. I don't want to pull the head off the bike again if I can help it.
If I buy bolts that are 3mm longer would this hold up to the stress of the cam rotating ? What grade of bolt ? Stainless steel ? Use locktite or anti seize ?
Can I go back with the same size helicoil or do I need to go to a larger size ? Use locktite ?

My thanks to all the contributors to this site,
Nick

[blowerbike]

i think you speak of soft threads pulling out.
heli-coils are stainless and do not break apart.
double check and then you have the choice of heli coils or going to 1/4-20 sae bolts.
peeps will chime in ragging on the the 1/4-20 fix but....it will last the life of the bike.

[luvnwunderwoman]

I assumed they were helicoils because most of them came out as one piece and were coiled. I have never seen a helicoil. Newby mistake.
If I tap for a 1/4 bolt should I use locktite or antiseize when I put it back together ?
Thank you very much for your advice,
Nick

[SqDancerLynn1]

I would use the correct metric size

[tkent02]

The next metric size up from 6mm is too big I think. I might try the 1/4 20.

Helicoils work too, or one of the better brands.

[JTGS850GL]

The stock bolts were class 9.9 and are approximately equal to grade 8
SAE. Don't use anything less then that. New bolts I just purchased from Suzuki came in marked as a class 10 bolt, so it looks like Suzuki upgraded the bolts even more.

If it were me I would put new Heli-coils back in the ones that had them and keep the stock bolts. Remember to use a torque wrench that's appropriate for the torque of the bolt.

[four_shot]

X2, with the original threads already gone, you probably won't need to drill the hole ovesized to prep for the heli-coil. Just make sure to get a good quality kit.

[blowerbike]

hey guys....it didn't have heli coils............
it will need drilled and tapped for heli coils.
1/4- 20 is self tappers with no real work needed.
80hp or 300hp engine...the 1/4-20 will get you out of a bind and last forever..

[derwood]

i vote for 1/4 - 20 unf

[luvnwunderwoman]

I purchased 1/4 20 stainless steel bolts and a new tap to thread the holes. Is self tapping a better way to go ? Will these bolts self tap or do I need to get self tapping bolts ? I also have blue locktite, should I use this ?

[SVSooke]

I would use what you have,not a fan of self tappers.

[tkent02]

I purchased 1/4 20 stainless steel bolts and a new tap to thread the holes. Is self tapping a better way to go ? Will these bolts self tap or do I need to get self tapping bolts ? I also have blue locktite, should I use this ?

Tapping should work, did you get a bottoming tap?
It cuts threads almost all the way to the bottom of the hole.

[chef1366]

SS self tapping bolts? No.
use tap and make sure you grease it. Clean it a few times while cutting each thread.

[JTGS850GL]

These bolts are relatively critical and stressed. I've never seen 1/4-20 grade-8 self-tapping screws. Are you sure you're using screws of the correct strength? If you use a common grade-5 or less screw you may have a problem in the end.

[blowerbike]

use a tap...basically do what chef said.
don't try to get to close to using the full depth of the hole...you could end up having problems.
i would use the same or just a tad longer SAE 1/4-20 bolts...don't go for full depth.
tork to 90" lbs when done.
it's a 2 way deal...the cam chain hold's the cams down and the valve springs try to push the cams up.