Power valve bearings mods

[p51mustang]

Is there any performance gain or easier maintenance that would come with this mod?

It's not something that would be seen.

Not sure why this would be a good thing.

Hi smoker i don't no what gain there is I am just pissing around with this who noe's it mite just work

[p51mustang]

A few years back there was an Italian RZ nutter who Very skillfully fitted ball bearing races to his PV's.
Excellent craftsmanship. So it's clearly possible.
There was no evident follow up though .. as in: How did this improvement work survive carbonised goop /exhaust .
Not very well on a street use engine..I would guess.
PV's as designed by Yama are poorly thought out.
The ali shafts turning in their bushings get chewed up rather quickly. Doubly quickly when there is no maintenance .
IMO a permanent fix would be to fit steel sleeves to the PV bearing shaft bits then bore ream the Bushings to a decent fit.
Far cheaper than buying fresh Bushings which would still have a clapped out fit.
Likely a simple and durable "fix" for what Yama San bungled.

Yes bear some thing like that its all in my head still but you are close

[p51mustang]

A few years back there was an Italian RZ nutter who Very skillfully fitted ball bearing races to his PV's.
Excellent craftsmanship. So it's clearly possible.
There was no evident follow up though .. as in: How did this improvement work survive carbonised goop /exhaust .
Not very well on a street use engine..I would guess.
PV's as designed by Yama are poorly thought out.
The ali shafts turning in their bushings get chewed up rather quickly. Doubly quickly when there is no maintenance .
IMO a permanent fix would be to fit steel sleeves to the PV bearing shaft bits then bore ream the Bushings to a decent fit.
Far cheaper than buying fresh Bushings which would still have a clapped out fit.
Likely a simple and durable "fix" for what Yama San bungled.

Yes bear some thing like that its all in my head still but you are close

OOPS Bare better spelling

[two-stroke-brit]

thats what i did , the PVs were only worn on the inside journals were the coupler fits.
so i turned them down to clean dias and sleeved them back to size.

[p51mustang]

I like that vary nice how much press did you use on the sleeve

[p51mustang]

This is a bearing from vxb bearing it is ceramic hy bird sealed only 12 $$

[two-stroke-brit]

I like that vary nice how much press did you use on the sleeve

it was a .0005" interference fit,
i just put the valve in the freezer and warmed the sleeve with a heat gun and it fell on.
i was tempted to close the tolerance between the PV and the bushing but kept it std.

[p51mustang]

Nice I have a 2nd bike that i hard anodized the power valves ran it all summer i haven't taken it a part yet to see what may be going on in there in all i am just pissing around with this stuff

[Bare]

This is a bearing from vxb bearing it is ceramic hy bird sealed only 12 $$

From Expereience: VXB bearing shop stuff is Sketchy... at best .
Mine were so bad I had to chuck them in the trash right out of their baggie.
A Chinese 12$ Ceramic bearing...where a Decent Quality First World made one is ~100$ +.
You Really? willing to fit one.

[p51mustang]

This is a bearing from vxb bearing it is ceramic hy bird sealed only 12 $$

From Expereience: VXB bearing shop stuff is Sketchy... at best .
Mine were so bad I had to chuck them in the trash right out of their baggie.
A Chinese 12$ Ceramic bearing...where a Decent Quality First World made one is ~100$ +.
You Really? willing to fit one.

Thanks Bare no I wood not use a 12$$ chine made bearing remember just pissing around here on this you never no some thing just mite work for change trust me i no what good bearing are and the cost 900 bucks for my doge challenger rt ceramic wheel bearings they are the best money can by OK back to pissing around

[motoholic71]

I think it's a waste of time like a ceramic bearing to turn 1/8 at 0.0001rpm ???
More important is to keep the coupler area clean because the front wheel projects dirt there and the seals start leaking and then dirt gets in there... so a protection might be much more effective. Also the loose clearance is needed because the valves get really hot. They could have had water circulating under the exhaust port.

[(F5)]

I made a simple flat thin steel shield shaped with tin snips retained by the inner header bolts.

[motoholic71]

Remember ; just

[p51mustang]

Thanks Motoholic 71 that about sums it up