Thread: Riva head question
12-17-2005, 08:37 PM #1
Riva head question
Have a riva head, I got it from Carl at IR, and he sent me the bolts also. I was wondering though, I've heard not to use the bolts that come with the riva head, how true is that? I believe they are stainless steel as I tried a magnet on it and it did not pull on the bolt or stick to it for that matter. Any thoughts?
12-17-2005, 11:41 PM #2
you might want to pm fernando, he is a bolt expert and polishes all of them in his ski after each run. LOL...but he should be able to help you on that.
12-19-2005, 10:30 AM #3
You dont want to use stainless bolts for a couple of reasons...they stretch WAY too much and also dissimular metals corrode. They could "lock up" in the holes and cause further problems.
12-19-2005, 11:08 AM #4
That might be, but darn near all the bolts ARE stainless.
12-19-2005, 01:35 PM #5
I've never had a problem with stainless head bolts, either from the Riva/R&D heads or OEM heads. It was the cheap-ass aluminum parts in the Riva girdle kit that gave me fits!!!
12-19-2005, 07:24 PM #6
So the head bolts for the riva head are fine, its the girdle ones that were messing up? Someone also mentioned just getting to more head bolts from a stock head to come up with the total that I would need and use the stocker headbolts on the riva one. Any thoughts on that?
12-19-2005, 08:12 PM #7
Most are using the stock head bolts...on a 1200 you need 2 extras, on a 1300 you need 4 extras. I got myself in a pinch and had to use a couple of stainless bolts. They work but there is always the electrolysis factor and they STRECH WAY TOO MUCH. I thought I had stripped the damn thing...it took sooooo much to torque it
12-19-2005, 08:17 PM #8
Every head bolt I have on my skis are SST. What are you talking about? What material is YOUR head bolts made of?
12-19-2005, 08:22 PM #9
I dont know the exact compound, but I got them at an industrial supply house. It just seemed to spin twice as far to torque the damn things. Maybe I got a bad batch. I felt the Riva bolts had the same problem. Especially after they had been torqued once already
What are your feelings
12-19-2005, 08:30 PM #10
There are probably 10 different types of stainless bolts. I've always used the recommended bolt for the recommended purpose.
Dielectric breakdown due to dissimilar metals shouldn't be a problem, if you have some type of sacrificial anode in the head, pump, etc...
Stainless and aluminum are compatable. No problems there if anode around there.
However, you will notice the brass nuts on the stainless on non-grounded places all over the ski. This is for dissimilar metal issues that you mention.
It's just not a problem with the heads... and yes, there are such things as bad bolts. There are also things such as torque wrenches that don't get calibrated once a year, and also such a thing as not torquing them correctly. I've done it.
Also, an Oring head functions WAY DIFFERENTLY than a head with a gasket. An O-ring head seals by way of aluminum/aluminum contact. The Oring is generally there to keep water in the right channels and out of the cylinder.
A head with a gasket will exhibit a crush effect for it's sealing, and will need another torque after the head warms up. You need to retorque the head to YAMAHA specifications, when it warms up, and recheck it after 20 or so hours.
Stainless bolts have different torque settings than aluminum bolts, or carbon bolts, or titanium bolts. They all work differently.
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