Super Jet Studs instead of head bolts

[Matt_E]

I get pretty tired of Yamaha head bolts stripping or breaking. Granted, it doesn't happen very often, but once or twice a year is enough to make me very uncomfortable whenever I torque my head bolts (also not very often).
Art at Jetworks told me last week that ADA now offers a stud kit for Yamaha cylinders. I think it offers enough convenience and peace of mind that I'm getting one.
Figured I'd throw it out there.

 

[oxnard111]

Doesn't sound like a bad idea... with different head thicknesses you'd have to make sure the studs would be long enough, but you have to do that with bolts any ways. might be a little tricky getting a girdled head on and keeping the combustion o-rings in place, but that might already be a problem with the ADA style heads anyways with the 6 girdle studs sticking up.

The Cold Fusion head I run uses girdle bolts instead of studs.

 

[QJS]

Kawasaki use studs and I suppose its fair to say they dont strip because they don't get removed so much. However, it can be a pain to get the head off, I've seen plenty of badly gouged Kwak heads and cylinders through people trying to get the head off. The trick is to take all the nuts off, leave the plugs in, put your hand on top of the head and push down then crank the engine. This breaks the seal and it comes off easily, same applies to a Yam with a stock head gasket, they stick like hell. Whenever I strip a Yam I always put a tap down every hole to clean them out (m8x1.25) this helps preserve the threads.
Chris.

 

[Andrew1289]

I read one of Smoky Yunik's (sp) engine books. He mentioned he always uses studs. Something about how it holds the head, or main caps down better. Maybe distributing the load more evenly, I forget. But what I got from it, just use studs.

 

[Waternut]

Studs offer better clamping force for the same torque. They also provide a more accurate torque value because the shank isn't twisting. I had problem getting my kawi head off but that was more because it was a gasket head and not an o-ring like we're all used to these days.

I know supporting the jetski industry is a good thing but I can't see spending $70 on a stud kit from ADA when I can buy 10 studs from mcmaster carr and 10 acorn nuts all in stainless steel for under $20. It's one thing for the girdle studs to cost that much because they're non-standard threads but the head bolts are pretty standard.

 

[#ZERO]

The Kawasaki stainless studs and acorn nuts work well with the Yamaha cylinders but they're a little pricy.

I'd be curious to know how much the ADA kits are selling for and if it's all stainless hardware.

 

[Tyler Zane]

very interesting, there going for about 70 bucks (it better be stainless!!!) so i would like to hear some more positive feedback but its defiantly on my mind.

i would like to see this come up on the mcmaster-carr parts list! i dont even care about the nice shinny acorns.

 

[Matt_E]

I'll post pics once I get my cylinder back from Art.

 

[GIL]

When Art re-ported my Lamey this year he installed Kawi studs in the cylinder and stainless acorn nuts. I couldn't be happier. My Lamey cylinder is a cast version and the threads never held up worth a dam-problem now solved!!!

 

[Waternut]

Alright here is a list. It's a little more than I thought because the studs have to be a little longer than I anticipated.

First the dirty details... My cylinder will accept 22mm of thread before it bottoms out. My head is 39mm thick. The washer will be close to 2mm and the nut is 6.5mm thick. Since you need at least 2 threads above the nut, figure an additional 2.5mm. You don't want to bottom out the stud in the cylinder but you want to be close. So add all of that up and I get 72mm. If you take 2mm away from the cylinder grip, it won't hurt much.

So IF I were to buy the studs from Mcmaster-carr, here is a list. Everything is 18-8 stainless.

70mm stud - 93805A366 - $2.36ea (10 needed)
1m stud - 90024A080 - $8.31ea (if you're feeling cheap, you can always cut to length)
washers - M8 - thickness to suit ($7 for 100)
regular nuts - 91828A410 - $10 for 50
- 91028A664 - $4 for 10
acorn nutes - 94000A039 - $7 for 10

If you're a real tight wad, you can cut the studs to length yourself and have everything for under $20.
If you want normal studs and the nice acorn nuts it'll cost about $38.

Not a huge saving over the ADA website but if you're like me, I always have stuff in my mcmaster-carr basket waiting for a few more things to be added so I can combine shipping.

 

[sjetrider]

I hate them LOL, Have to remove them for honing or boring or whatever and they just get in the way. I have the ADA set on my billet motor and their nuts are rediculously easy to cross thread or gull up. Just my opinion from someone USING them already.

But if ya want them from ADA I am a dealer and can get them for ya LOL.

Brian

 

[Tyler Zane]

, that a 30 dollar savings! thats a case of beer and a pack of smokes. good work waternut!

 

[Tyler Zane]

But if ya want them from ADA I am a dealer and can get them for ya LOL.

Brian

haha, i didnt even think about that.... you da man Brian

 

[Freakrider]

I stuff some never seize up into the ADA acorns nuts because they begin to rust on the inside...:ugh:

 

[easyrhino]

After stripping the 3rd bolt, I heli-coil the rest. Made a tapping block out of 1x1x5 oak and drill press.

 

[Roo]

I've never had this problem.

Use SYNTHETIC grease on your head bolts - works great.

(ive been using the Mobile 1 purple lookin' stuff in a tube i dip my bolt threads into)

 

[Waternut]

I've never had this problem.

Use SYNTHETIC grease on your head bolts - works great.

(ive been using the Mobile 1 purple lookin' stuff in a tube i dip my bolt threads into)

Uhh that is actually making the situation worse. By putting grease on the threads, you have less resistance between the threads and you are actually over torquing your bolts which means you're more likely to strip one. Just a heads up...

 

[superjetkev]

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Uhh that is actually making the situation worse. By putting grease on the threads, you have less resistance between the threads and you are actually over torquing your bolts which means you're more likely to strip one. Just a heads up...

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Uhhhh, actually your wrong. Why do you think ARP fasteners come with moly lube? so you get less friction between the bolt and the thread...therefore getting an ACCURATE torque. I worked in an engine machine shop for 4 years, now im an industrial millwright by trade and almost every bolt i do up states to use oil, grease, moly lube or never seize on the threads. Its just part of the procedure. If you set your torque wrench to 30 ft/lbs its gonna click at 30 ft/ lbs. And if the thread has a little bit of grease on it, it will be a TRUE 30 ft/lbs. just a heads up.

 

[Roo]

Uhh that is actually making the situation worse. By putting grease on the threads, you have less resistance between the threads and you are actually over torquing your bolts which means you're more likely to strip one. Just a heads up...

tell that to XScream Inc. there buddy