Super Jet Help: Stripped Factory headpipe to manifold bolt threads

[aramis]

I just stripped one of the threads on my Factory B-pipe exhaust manifold (one of the three holding the headpipe on). It gave up at 20 ft-lbs...you know that sinking feeling you get when you feel it start to strip? I hate that. This was the "single" bolt closest to the cylinder, the one that has a thru hole instead of a blind hole.

Anyway, I searched and couldn't find the answer. Is there enough meat to use a timecert here, or would a helicoil be good enough? Never done timecerts before and would have to buy the kit. Manifold is bored open to 47mm if that matters.

My tap and die set says it is an M10 x 1.25...does that sound right?

Thanks!

 

[Matt_E]

Timecert or Helicoil will work

 

[Freakrider]

Have used a heli coil before and then 20 ft/lbs with loctite...yes M10 x 1.25. Make sure bolts are long enough to grab enough threads...

 

[rubbertoe]

not sure about my sj but my kawi factory pipe manifold was a 1.75 fine thread if memory serves me correct.

 

[Matt_E]

Yamaha FPP manifold is indeed M10x1.25. Essentially one of the big bedplate-to-case bolts.

 

[ChadGnarly]

I will time sert it, good as new with stainless time serts. 10 bucks a hole pm me if interested.

 

[rubbertoe]

good to know ,i will have to remember this when doing work on the sj.

 

[Dmac80sc]

Pretty sure the bolts need to be torque to 30 ft/lbs too

 

[Twinturbostang]

Ya we time sert all of ours before they even strip on. Stainless timeserts you can rip down on the things and never even have to think that it could strip!!!!!

 

[Matt_E]

I've been using the same manifold since 2005, never a problem - and there were plenty of installs/removals.
I just sold it.

 

[Twinturbostang]

I've been using the same manifold since 2005, never a problem - and there were plenty of installs/removals.
I just sold it.

The problem is more the galling of the stainless and the alum. Then you remove them and that next time in the treads are weaker and they pull out. or if it galls real bad the thread come right out with the bolt even if there were put in right.
Once you timesert you never go back

 

[Matt_E]

Stainless? I've always used OEM Yamaha bolts, with a small amount of grease.
I've timecerted plenty of things and they work great. I just never had the need on the manifold in seven years.

 

[Twinturbostang]

OEM yami are stainless galvanized if i recall right, same as the ones factory pipes sells with their pipes. I use stainless alan socket heads wit zero problems since we timesert everything.
Everyone does their own thing. There is no "right" way. but i will tell you this i have never seen a tiesert strip and i have seen many alum manis strip.

 

[Matt_E]

I used the ss allan bolts once and had one gall. I got it removed by a machine shop without damaging the manifold. Went back to OEM bolts, never happened again.

 

[dbattersby20]

what's the purpose of the allen style screw over a standard screw?

 

[Twinturbostang]

Cap alan just fits nice on the head pipe with the limited room. And the full stainless doesnt rust and make a mess.

 

[speedysprocket]

I run all three with helicoils now. They're tricky to install because of the fine thread, but are plenty strong and stainless!

 

[Matt_E]

Cap alan just fits nice on the head pipe with the limited room. And the full stainless doesnt rust and make a mess.

OEM bolts don't rust, either :biggrin: but the ss Allen bolts do look nicer

 

[GIL]

Matt, I was in your boat until this past weekend. I now have a manifold that is ported to hell and back to match my Lamey cylinders and 2 of the 3 holes are stripped bigtime! Must have been all the b/f's in the surf. LOL

 

[motoman96]

Matt, I was in your boat until this past weekend. I now have a manifold that is ported to hell and back to match my Lamey cylinders and 2 of the 3 holes are stripped bigtime! Must have been all the b/f's in the surf. LOL

Since when can you flip?lol