Motoscrubs.com

Hi folks,

Does this look ok to you? it must have been like this before I stripped it.

New rocker spindles, same shims in place with the spring washer having no other shims either side.

I wouldn't be happy with that, should be dead centre on the valve, re arrange your shims,or if you can't sort it with what you have get some more shims from Nigel, (I personally would scrap the spring spacer and replace it with solid shims)
Cheers,
George

Thanks George,

I also not happy about the springs as it looks like it can turn and wear the alloy in the head.
I could shim it as you suggest.

Regards

Moved the spring washer and shims to opposite side, looks much better now
But will go all shims later

That is a curious valve adjustment screw. Every bevel single with set screw type valve adjustment I’ve ever seen employed the “elephants foot” type adjuster and no shim on top of the valve stem. Is this a factory arrangement or improvised?

Matt

This is what was fitted when I got the bike, I assumed this was the original setup. The previous owner said he had never done any work on the bike so it must have been like that for a long time. The valve stem has a shim cap on it with the adjuster contacting on that, it has a slightly radiused contact area.
What should the setup be?

Regards

The normal (expected) rocker on a widecase single is the solid foot version, with no adjustment facility, the valve clearance adjustment is achieved by changing the thickness of the hardened cap on the valve stem.
Cheers,
George

I have a widecase mark 3 350 and it has adjusters but not like in the pic. Seems a bit strange to have an adjuster as well as a shim cap.

It seems you probably have an original equipment adjustment screw after all. I looked up the part number for the adjustment screw but the first illustration looked like the adjuster had a hex on it similar to the adjuster you have. I turned to the next page in the parts catalog and the illustration did not show a hex on the adjuster. This number (660) is the “elephant foot” adjuster I previously referred to. The 660 adjuster employs a captive ball with a flat ground on it in the end of the adjuster. The flat contacts the end of the valve stem and the ball rotates as the rocker arm moves through its arc. These adjusters are used on every Monza and Sebring I’ve encountered. According to the parts catalog, the adjuster with a hex on the end (190) were used on GT’s up to engine number 87421. It occurred to me that these adjusters might have been used on 175’s or 200’s but the service manual shows the 660 type adjuster on these engines. So it seems you have original adjustment screws that are unique to the early GT’s (unless they are also used on 125/160’s or some such). Note that the parts catalog did not show valve caps employed with the 190 adjuster but there is certainly no harm in doing so and is probably beneficial.

Matt

This could have been original but I can't tell.
With the shim caps on it would prevent any valve stem wear at the end and I could adjust it by the normal method, I thought it was a clever bit of design. The bike had been running like that, I am happy to keep that setup if it can work reliably, it would be a lot easier to get the valve clearances done.
I thought the shim only adjustment was for desmo models, I never knew there were a few variations. If no one else has seen a setup like on my bike then a PO must have modded it, not sure why as the valve ends looked ok.
If I keep this setup, is there any chance of those shim caps bouncing up and down within the valve clearance or will the oil "stiction" keep them in place?
This has been the most time consuming engine I have ever worked on, seems to be an issue at most steps in this build but a lot of that is down to my inexperience with these engines.

regards