Exhaust Header Bolt

[Roostabunny]

Found the source of my noise, and now I'm on to the next problem.

Stopped at Ace and bought an M8 x 1.25 x 30 Stainless bolt, but I couldn't seem to get it to thread in.

I was a little suspicious in the first place that one out of 4 headers already had stainless bolts, and when I investigated I found out why. At least some of the threads are missing and a 30mm bolt won't grab. There was a stainless bolt in there before - PO must've broken the bolt and messed up the hole getting it out or just stripped the hole and the replaced the bolt with a longer one? 35mm?

Here are my questions:

I ride every day - can I try a 35mm bolt for now? How long can the bolt be before it'll bottom out in the hole?

Long term? I saw the Timesert kits seem to be well reviewed, and the M8 x 1.25 kit comes with an 11.7mm insert but it looks like it'll cost me $75! Eeks. Do I need this if I can get the longer bolt to work? Any other recommendations?

Thanks!

[80GS750]

if its all screwed up in there your gonna have to put in an insert....

really sucks but its worth it.

i had to have 4 put in my old 750

[mriddle]

35 is the correct length for your bike.

Found the source of my noise, and now I'm on to the next problem.

Stopped at Ace and bought an M8 x 1.25 x 30 Stainless bolt, but I couldn't seem to get it to thread in.

I was a little suspicious in the first place that one out of 4 headers already had stainless bolts, and when I investigated I found out why. At least some of the threads are missing and a 30mm bolt won't grab. There was a stainless bolt in there before - PO must've broken the bolt and messed up the hole getting it out or just stripped the hole and the replaced the bolt with a longer one? 35mm?

Here are my questions:

I ride every day - can I try a 35mm bolt for now? How long can the bolt be before it'll bottom out in the hole?

Long term? I saw the Timesert kits seem to be well reviewed, and the M8 x 1.25 kit comes with an 11.7mm insert but it looks like it'll cost me $75! Eeks. Do I need this if I can get the longer bolt to work? Any other recommendations?

Thanks!

[RJz1100E]

Personally I like those inserts much better than helicoils. They give a little beefier hold on a bolt and easier to get in right. We use large ones at work and they've got great holding power.

[Roostabunny]

So what do you think? I don't want to spend $75 on the kit for one hole - maybe check machine shop prices?

[Steve]

So what do you think? I don't want to spend $75 on the kit for one hole - ...

How many inserts are in the kit? Do all eight holes if it makes you feel better.

.

[80GS750]

i hate to tell you, but i spent $75 a hole when i had to fix mine, at a machine shop...

[Roostabunny]

How many inserts are in the kit? Do all eight holes if it makes you feel better.

.

It doesn't, but then again...

i hate to tell you, but i spent $75 a hole when i had to fix mine, at a machine shop...

... I wasn't expecting this either.

5 inserts to a kit, I believe. Time to call my wrench buddy who does lots of work on metric Police bikes. Maybe he's got a kit and I can just pay him for the insert. If not, then you're right, Steve - $75 for multiple holes (haven't tried the other manifolds) definitely sounds better than $75 for one.

[hampshirehog]

Those threads in the head are usually a lot longer than are needed for a 35mm bolt - you might be able to use something quite a bit longer (maybe 50mm or more) to get in to good thread.

[Roostabunny]

Those threads in the head are usually a lot longer than are needed for a 35mm bolt - you might be able to use something quite a bit longer (maybe 50mm or more) to get in to good thread.

I'll give that a shot - looks like I've got over 40mm of hole depth and only a 30mm bolt.

I'll bet it works - after all, the bolt that was in there stayed for almost a year after I bought the bike. There must be some good threads in there.

[Suzuki_Don]

In OZ we use inserts called RECOIL which is a wound stainless thread that is easy to put in. After you have fixed the one you are having trouble with then do the others with this cheaper method. The inserts are only .50c each. Drill out each hole, run the tap in and insert the new thread. I did all the exhaust threads and the tappet cover threads for less than $20.

[bwringer]

In OZ we use inserts called RECOIL which is a wound stainless thread that is easy to put in. After you have fixed the one you are having trouble with then do the others with this cheaper method. The inserts are only .50c each. Drill out each hole, run the tap in and insert the new thread. I did all the exhaust threads and the tappet cover threads for less than $20.

They're called Helicoils here, and I hate the durn things because the coil inevitably comes out the next time you disassemble things.

That said, they're better than nothing, cheap, plentiful, and pretty strong if they're installed correctly.

[Roostabunny]

What the heck?

Uh oh - now really starting to wonder. Any chance the PO put this thing back in the JB Weld or similar? Can't even get my 40mm bolt in there with whatever this crap is.

My guess is that he used something sketchy and it eventually vibrated its way out. The material from the front of the hole is probably still in the threads of the bolt that fell out.

Any thoughts about what the stuff may be?