RZ 350 Power Valve removal

[Evans Ward]

Oh well.... I did use the billet coupler from Fast From The Past. Hex heads are so much easier especially in critical spot applications.

[silverstrom]

Hex heads are so much easier especially in critical spot applications.

Agreed...see my post #9 about the screws.

[silverstrom]

I hear ya. I meant like to use it to take up the looseness on the Coupler itself. Or just tightening it over spec works well enough?

If proper clamping force doesn't hold them, nothing will. The coupler will wear. It's inevitable. You either fix what you have or buy a new one.

[kpke]

Dont use stainless in alloy.... These are M4 and the coupler is cast, not a great recipe if they bind. Just use a normal zincd hex bolt.

Yes they will but... I use SS in this application and all over my bikes where high strength steel is not required. But I also use copper anti-seize on these fasteners to keep them from binding. I also polish the fuk out of them because they are pretty like that all shiny you know, and they stay pretty. The worst binding will occur in SS to SS fasteners. At work the giant X billion dollar machine has no ferrous metal anywhere. Where there is SS to SS fasteners required the screws/bolts get silver plated for lubrication and to keep from binding.

OP, remember what silverstrom said about removing some material from the one or both of the mating surfaces on the coupler to get more clamping force.

You should at a minimum take that whole top end apart for inspection. Post results here and you will get all the help you need.

[JonW]

Dont use stainless in alloy.... These are M4 and the coupler is cast, not a great recipe if they bind. Just use a normal zincd hex bolt.

Yes they will but... I use SS in this application and all over my bikes where high strength steel is not required. But I also use copper anti-seize on these fasteners to keep them from binding. I also polish the fuk out of them because they are pretty like that all shiny you know, and they stay pretty. The worst binding will occur in SS to SS fasteners. At work the giant X billion dollar machine has no ferrous metal anywhere. Where there is SS to SS fasteners required the screws/bolts get silver plated for lubrication and to keep from binding.

OP, remember what silverstrom said about removing some material from the one or both of the mating surfaces on the coupler to get more clamping force.

You should at a minimum take that whole top end apart for inspection. Post results here and you will get all the help you need.

Interesting you suggest copper anti seize Ken, most things Ive read advise against that with SS in alloy as it makes the corrosion worse.

[kpke]

Dont use stainless in alloy.... These are M4 and the coupler is cast, not a great recipe if they bind. Just use a normal zincd hex bolt.

Yes they will but... I use SS in this application and all over my bikes where high strength steel is not required. But I also use copper anti-seize on these fasteners to keep them from binding. I also polish the fuk out of them because they are pretty like that all shiny you know, and they stay pretty. The worst binding will occur in SS to SS fasteners. At work the giant X billion dollar machine has no ferrous metal anywhere. Where there is SS to SS fasteners required the screws/bolts get silver plated for lubrication and to keep from binding.

OP, remember what silverstrom said about removing some material from the one or both of the mating surfaces on the coupler to get more clamping force.

You should at a minimum take that whole top end apart for inspection. Post results here and you will get all the help you need.

Interesting you suggest copper anti seize Ken, most things Ive read advise against that with SS in alloy as it makes the corrosion worse.

Hmmm. I've not had this happen at all Jon.

[Evans Ward]

I used reg antiseize grease on my SS hex heads too but still tightened them very securely when installed.

[JonW]

Well I used it for years on fastners like stainless engine case screws and then people started to advise me it was a mistake and I googled 'galvanic corrosion aluminium cooper stainless steel' or something and there was a lot of stuff about it.

[kobra]

On my build I used "zinc coated" screws everywhere. That way, you can get strong 12.9 grade screws, great corrosion resistance, and no worry of hydrogen embrittlement. They are the opposite of shiny though, just a matte silver appearance.

People get varying results with stainless screws because it needs an electrolyte to promote the galvanic reaction. If you have a dry weather garage queen, it will be fine for years. Anything else and you will see local aluminum corrosion under the heads of the bolts.

As for the coupler... I am pretty sure it's rubberized to allow for some misalignment. I used hex screws in mine. No more phillips heads left on the bike.

[RuZty]

I didn’t see any mention of the bearing surface. If your valves or the bushings have excessive wear (ie. visually not round) you are wasting money on new seals because they will be leaking again in no time from running off centre. The bushings are expensive but better to fix it right the first time.

[silverstrom]

I didn’t see any mention of the bearing surface. If your valves or the bushings have excessive wear (ie. visually not round) you are wasting money on new seals because they will be leaking again in no time from running off centre. The bushings are expensive but better to fix it right the first time.

Which is another good reason to (already been suggested) pull the top end and see what you are working with. Otherwise you are just shooting in the dark and hoping for the best.