Valve adjusting?

[Squishman]

I just acquired my 1980 XS650 street tracker with 750 cylinders, mildly ported head and XS Performance Cam. He put 1270 miles on it since the build. Originally, the bike had approx 7500 miles on it. What do I need to understand about periodic valve adjustments? Obviously, I cannot just open a Clymer's manual for it! Is there a break in? Should it be checked soon? Or do I have multiple thousands of miles before I even have to consider this?

 

[Wingedwheel]

If you have doubts it’s a very easy process detailed in the manual. Typically on a break-in I like to do a half dozen or so heat cycles, then pull the tank and top mounts to re-torque the head. While it’s wide open, check the cam chain tension and then the valves. Others may have different methods but that has worked for me. Are your valves noisy?

 

[Squishman]

If you have doubts it’s a very easy process detailed in the manual. Typically on a break-in I like to do a half dozen or so heat cycles, then pull the tank and top mounts to re-torque the head. While it’s wide open, check the cam chain tension and then the valves. Others may have different methods but that has worked for me. Are your valves noisy?

No. I only test rode it before I bought it 3 weeks or so ago. Hasn't even been started since, since we got majorly hit by snow and I am working on some things on it in the meantime. But, no, it sounds beautiful and perfectly fine. I am only thinking ahead here.

 

[Wingedwheel]

It sounds like you have enough miles on the build where it probably wouldn’t hurt to check. After you go through the process once it’s very easy.

 

[Squishman]

It sounds like you have enough miles on the build where it probably wouldn’t hurt to check. After you go through the process once it’s very easy.

I might have to have someone here that knows what the cam tension etc. should feel like. Anyone in the Twin Cities (Apple Valley) that might be free some Saturday morning this Spring or early Summer?

 

[gggGary]

Setting valves is pretty straight forward, lots of how to's around here.
The cam https://www.mikesxs.net/performance-camshaft-and-valve-spring-kit-yamaha-xs650.html
came as a kit, the question is what would be the recommended valve clearances when using THOSE components.
In general the factory valve settings are more about reduced noise than best practices, larger is probably better, but few want their motor to sound like you're beating a pan with a spoon.

Ducati owners are excused.................

 

[Squishman]

Setting valves is pretty straight forward, lots of how to's around here.
The cam https://www.mikesxs.net/performance-camshaft-and-valve-spring-kit-yamaha-xs650.html
came as a kit, the question is what would be the recommended valve clearances when using THOSE components.
In general the factory valve settings are more about reduced noise than best practices, larger is probably better, but few want their motor to sound like you're beating a pan with a spoon.

Ducati owners are excused.................

So that's my cam! Cool!

 

[5twins]

Typically, we use .003" on the intakes and .006" on the exhausts but as Gary just mentioned, your aftermarket performance cam may spec different clearances. You'll need to research that.

Setting or checking the cam chain tension is very simple if done while the engine sits there idling. The manual gives a static adjustment method that is difficult and easy to screw up. Doing it while the engine idles is virtually foolproof. I had an SR500 and the cam chain adjustment procedure on that was pretty easy. You set the motor at TDC and adjusted the chain. It worked on that bike because at TDC, there was no tension on the chain from valves being open. After adjusting, you are instructed to start the engine and observe the little plunger in the end of the adjuster bolt for movement. No movement means you've set it too tight. Here's an excerpt from the SR500 manual .....

Unfortunately on our 650, there is no spot during the engine's rotation where there isn't at least one valve applying pressure to the cam and cam chain. That means there's no one spot the motor can be set at, like the TDC mark on the SR500, to do the chain adjusting. But I thought, what about the second part, the checking part by starting the motor, why couldn't that be applied? Turns out it can, and I do, lol. This makes it so simple. Remove the acorn cover nut, start the motor, and observe the plunger movement. You want to see a small amount of in-out movement, maybe a MM or 2. More than that indicates the chain is too loose and little to no movement means it's too tight. The way I do it is loosen the locknut then tighten the adjuster until the movement stops or almost stops, then loosen it back up until I get the small amount of movement I want. To me, this gives the perfect setting, just a bit looser than "too tight".

 

[gggGary]

But I thought, what about the second part, the checking part by starting the motor, why couldn't that be applied? Turns out it can, and I do, lol.

Agreed, I think it was XSLeo that first advocated this method. He said tighten til plunger movement stops then back off 2 flats of the nut (1/3turn) but... I remove the plugs and use the electric starter instead of idling. MUCH simpler, cleaner, safer.

 

[5twins]

I should also add that I do this when the motor is hot. Set it on a cold motor and the chain may end up being too tight once things heat up and all the parts expand. Also, according to the manual, it should be checked every 4000 miles. That's too long apparently. Several years back, a member who had one of these new back in the day said his dealer told him this, and to check it more frequently, about every 1000 miles. Being that oil changes should be done about then (1000 to 1500 miles), I've added the cam chain check/adjust to my oil change routine. The motor's hot already so I check the chain tension then change the oil.

 

[Squishman]

This is all such great stuff. Definitly good info. Thx.