valves ajustement

[laloualfa]

I rebuild the engine of my XS-650C 1976 lately, change piston,pin, big cylinder,chain, bender, Xs performance rocker arm set
with the hex screw valve ajuster from Mike XS.

the poblem I have is the valves clearence don't stay ajusted for a long time.
after 100km the bike starts to make big noise from the top of the engine
after checking, the clearence was off
exhaust should be .015 is now .035
intake should be .002 is now .003
after reajustment i took a ride and samething happened.

I'm starting to suspect the new hex ajuster screw, maby the iron is not hard enough or bad quality.
I noticed that the metal of the lock nut is not the same color as the screw and also that the difference in clearence is greater on the exhaust side than intake.

I own that bike from new (44 years) it is not the first time that i adjuste the valves on this bike and it is the first time this has happened to me.

has this ever happened to you?
thanks

 

[gggGary]

Haven't heard of it happening. Are they "elephant foot" or can you back them out through the guides to take a better look? If you can remove them; perhaps compare intake and exhaust. Later model Yamaha, Virago? adjusters are hex and are available.

 

[Jim]

Don't remember who, but someone here recently had the same problem. Turned out to be the oil pump wasn't pumping oil and the rocker arms were quickly destroying themselves. You sure it's getting oil to the top end?

 

[laloualfa]

Haven't heard of it happening. Are they "elephant foot" or can you back them out through the guides to take a better look? If you can remove them; perhaps compare intake and exhaust. Later model Yamaha, Virago? adjusters are hex and are available.

thanks Garry
what is elephant foot?

 

[laloualfa]

Don't remember who, but someone here recently had the same problem. Turned out to be the oil pump wasn't pumping oil and the rocker arms were quickly destroying themselves. You sure it's getting oil to the top end?

thanks Jim
well when i removed the valve cover eveything look oily

 

[Jim]

thanks Jim
well when i removed the valve cover eveything look oily

Well, I'm hoping all's good with the oiling, but keep in mind that the cam chain will sling oil up there and make it look oily but that doesn't mean the pumps working. To make sure you need to look at the rockers while it's running and make sure oil is flowing.

 

[gggGary]

thanks Garry
what is elephant foot?

have a cap on the bottom to spread load.

 

[gggGary]

The correct hardness for the tappets is a fine line, the stockers are surface hardened and sometimes both adjusters and valve stems show galling. We did some experiments with reground tappets and with that hardened surface gone they showed a wear path in the face relatively quickly.

 

[laloualfa]

Well, I'm hoping all's good with the oiling, but keep in mind that the cam chain will sling oil up there and make it look oily but that doesn't mean the pumps working. To make sure you need to look at the rockers while it's running and make sure oil is flowing.

i see then i will disconnect the oil delivery pipe at the top to see if oil is coming, that will at least confirm the oil pump is working
thanks Jim

 

[laloualfa]

have a cap on the bottom to spread load.

her is the one I use from mikeXS
Wow i like it, where do you get those? are they fro

m virago?

 

[gggGary]

Why don't you take one out and snap a pic?
Elephant foot adjusters can only be installed when the head is off.
http://www.xs650.com/threads/elephants-foot-valve-adjuster-comparison-porsche-vw-mikes.32559/

 

[laloualfa]

Why don't you take one out and snap a pic?
Elephant foot adjusters can only be installed when the head is off.
http://www.xs650.com/threads/elephants-foot-valve-adjuster-comparison-porsche-vw-mikes.32559/

 

[gggGary]

WOW! Yeah those are soft smooshed in junk. Best to go get some genuine Yamaha adjusters.
Good news is they are cheap and easy to replace. Still got your original adjusters?

http://www.xs650.com/threads/mikes-tappet-adjusters.24450/#post-241329

https://www.partzilla.com/product/y...?ref=3064e51e484478879aeca4dbf22e8a5910d01771

 

[gggGary]

Yes we do see some spalling on stock adjusters, and they prolly are a "service replacement" item but they are both cheap n easy to install.
Reminds me I should prolly look at the ones on Madness, they've seen a lot of miles with a race cam.

 

[5twins]

Those wouldn't be the 1st MikesXS parts that got skipped during the hardening process. I had a clutch pushrod that they missed. It was pretty much shot by 10K miles, about to begin shedding metal bits.

 

[Paul Sutton]

The quality valve adjusters do not show machine marks on the face and are polished. Polished/Ground finish is not always a mirror finish. At the current price the Virago XV750/1000/1100 seem a good choice. The smaller Viragos have 6mm threads so too small. I have used VW screws but you need the genuine article which is also polished/ground. There are many after market VW screws out there that are soft and wear quickly. They are easily spotted because they are not polished and are machined to more of a cone rather than ground spherically.

Note: I see those Flat Ball Valve Lash Adjuster Screws have appeared on Ebay by a US seller and they are listed for the XS bikes as well. The previous German supplier only ever listed them for the XT500. Has there been positive feedback on these for the XS?

 

[gggGary]

PS I would also use the OEM adjuster nuts.
A thread mentioning virago adjusters and stock adjuster spalling.
http://www.xs650.com/threads/1976-xs650-c-project-from-ireland.52822/page-3#post-577027

 

[gggGary]

Thinking out loud is there any reason we can't "just" pull the rocker shafts, remove rockers and install elephant foot adjusters?

 

[Paul Sutton]

You can pull the rockers OK, but maybe you cannot reinsert them with the elephant foot fitted?? Maybe you cannot screw in the elephant foot with the rocker in place either?? Those flat ball lash screws can be fitted in 2 parts i.e. screw in the threaded section from the top and place the flat ball in place from underneath so the engine does not have to be dismantled.

Edit: Dumbass here got it wrong, see the next posting by GJL for the correct answer. But, the flat ball valve adjusters are advertised as being easy to fit with no engine dismantling or rocker grinding required.

 

[GLJ]

Thinking out loud is there any reason we can't "just" pull the rocker shafts, remove rockers and install elephant foot adjusters?

The sleeve #8 has to be removed before the shaft can come out. It comes out the bottom of the cover.