Help with some comments on my YPVS operation appreciated

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torp68
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Help with some comments on my YPVS operation appreciated

#1 Post by torp68 » Thu Aug 18, 2016 6:37 pm

Hi

New to the RD500; new to this forum :razz:
Recently bought an -86 RD500 that has lived a bit of a rough life.
Engine has recently been overhauled with new cranks (US made the seller claimed..), bearings and pistons/rings.
My question is regarding the YPVS, which seems to have a lot of play in it between the cylinders and behind the left/aft cover (the only one I have removed).
Some oil found behind the left/aft YPVS cover when I took it off, and also a bit wet between the cylinders.
It apparently works as it should, tests ok with ignition turned on (and appears to give me the bottom/midrange pull that my NS400R lacks...)

Again; new to the RD so it might be normal for all I know, but I would be happy if any of you RD-pros could take a look and comment on it.
I just uploaded a short video on youtube on https://youtu.be/a4z4BY02WWE
Any help appreciated!

Thanks
Oyvind/Norway

MK
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Re: Help with some comments on my YPVS operation appreciated

#2 Post by MK » Fri Aug 19, 2016 12:48 pm

If the valve contour matches into the port in the shown position, then you have more work ahead than the coupler slack issue.
There's that "fork" on the coupler. It needs to half way match the bore in the left/right cylinder in open position.

If that not the case someone mistook the front and rear valves so you need to unmount the heads and at least one cylinder.
The good thing about that is that you can easily address (and fix) if its just a crushed rubber or worn valve shaft ends that cause the play.
Bye
Martin

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pstamper
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Re: Help with some comments on my YPVS operation appreciated

#3 Post by pstamper » Sat Aug 20, 2016 5:10 pm

I currently have head of bike and looked at the linkage connection and mine seem to be like yours. Not sure about ends.

torp68
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Re: Help with some comments on my YPVS operation appreciated

#4 Post by torp68 » Sat Aug 20, 2016 7:17 pm

All right. Thanks guys! Found so many "gremlins" after the previous owner already, I´ve come to the conclusion to tear off the heads and cylinders anyway.... Loosened up one of those crown nuts on the head today, since it appeared to have 3 copper washers underneath...... Got cooling water sipping out immediately... :smt014 Now; that´s not normal on a "newly refurbished" engine, is it......?? :mad:

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