V65 single spring valve upgrade proccedure

[Skiwi39]

V65 Valve spring upgrade.

Has anyone on this forum upgraded a V65 to the later single spring valve system from the Nevada/750?

I'm trying to find information on the process and to get feedback about whether or not it's a good thing and if doing so creates any issues. I've read a number of posts on different forums about doing this, but can't find anything that gives much detail about it. The article in This Old Tractor about small block issues said that "the jury was out" on whether or not this was a valid upgrade.

If anyone has any articles, or information they can share about this can of worms, I'd be grateful. I'd prefer to not have to dig a valve head out of my piston at some later date.

Cheers in advance!

[Antietam Classic Cycle]

I did the conversion to a customer's V65SP that had dropped a valve and was getting ready to drop another (head of the valve popped off). I bought #4 (part number 27037521), #5 (part number 31038015) and #13 (part number 31037015) in the illustration below.





In my opinion, there's no downside to it.

[Skiwi39]

Charlie - thanks for the input and parts diagram! Most appreciated!!

Julian

[Antietam Classic Cycle]

Happy to help.

[frozengoose]

I did the conversion to a customer's V65SP that had dropped a valve and was getting ready to drop another (head of the valve popped off). I bought #4 (part number 27037521), #5 (part number 31038015) and #13 (part number 31037015) in the illustration below.





In my opinion, there's no downside to it.

Hey Charlie, I've got an '84 v65 with about 40K miles, no issues, runs great. Is there any way to tell if this conversion was done? I've had it maybe 10 years, it had around 30K miles or so when I got it. Besides the parts listed (that are for a v75?), what other parts (v65?) would you replace. Thanks.

[Frenchfrog]

Just take off the valve cover and have a look...easy to see if there are two valve springs or only one.

[Antietam Classic Cycle]

Hey Charlie, I've got an '84 v65 with about 40K miles, no issues, runs great. Is there any way to tell if this conversion was done? I've had it maybe 10 years, it had around 30K miles or so when I got it. Besides the parts listed (that are for a v75?), what other parts (v65?) would you replace. Thanks.

Most likely it has not been done, most owners see no need to do it until it's too late. As Frenchfrog wrote, if the valve springs are a nested pair (smaller spring inside the larger one), then it hasn't been done.

The parts listed are for a Nevada/Breva 750. I'd replace the valves, guides and valve stem seals.

[Mayor_of_BBQ]

If you are waffling on it, check your valves every 1000 miles.. you will see if they are stretching or moving pretty quick! My v65 the exhaust lash was closing up within 1000-1500mi every time before I had the springs and valves replaced. I was lucky not to drop one before I got around to it.

[Pescatore]

I'm in the process of replacing a head gasket on a '91 V65GT.
This thread came at the right time, but no parts available from the usual sources.
I don't notice stretching, actually the exhaust gap is a smidge wider.  
Anyway, I guess that if any valve has stretched, it would have to be replaced as well?
And the same V65 valve part numbers can be used, or is there a preferred replacement?

[Antietam Classic Cycle]

I'm in the process of replacing a head gasket on a '91 V65GT.
This thread came at the right time, but no parts available from the usual sources.
I don't notice stretching, actually the exhaust gap is a smidge wider.  
Anyway, I guess that if any valve has stretched, it would have to be replaced as well?
And the same V65 valve part numbers can be used, or is there a preferred replacement?

Stein-Dinse has the parts.





I read somewhere that the original upper and lower retainers can be modified to work with the V7 spring. I've never tried that, so I'm not sure what's involved. 

[Pescatore]

Thank you, Charlie.  I was looking locally to save on shipping cost. Maybe it's not a big difference.


Don't we need 4 of each retainer too?

[Antietam Classic Cycle]

Thank you, Charlie.  I was looking locally to save on shipping cost. Maybe it's not a big difference.


Don't we need 4 of each retainer too?

Yes, a brain fart on my part. 

[Antietam Classic Cycle]

https://www.gutsibits.co.uk/pr/TheShop/index.php?q=31038015&f=d&Model=14&search=SEARCH

[Pescatore]

 

[frozengoose]

If you are waffling on it, check your valves every 1000 miles.. you will see if they are stretching or moving pretty quick! My v65 the exhaust lash was closing up within 1000-1500mi every time before I had the springs and valves replaced. I was lucky not to drop one before I got around to it.

OK, so I pulled the valve covers and checked gap. Three were spot on and one (intake) was .01 off. So that seemed OK to me. Is it really necessary to do an expensive and time consuming procedure on a bike that's running great. I don't mean to question anybody's experience/intelligence but it seems like overkill to me.

[Frenchfrog]

Only you can really make that call.If you are going to make really little use of the bike then perhaps you are right....