1980 xs1100 valve adjustments

[ACAL]

Hi,

Trying to get a 1980 xs1100 special up and running and found I have 145 psi in cylinders 1,2,4 and only 120 in cylinder 3. Seems to only be running on two cylinders so digging into the carb at the moment but want to trouble shoot the low compression. Any help on how to do so? Remove cover and head, find tdc and check clearances?

how do I know if I’m on the compression stroke and not exhaust stroke? And how do I check clearances on all cylinders?

thanks in advance!

[DiverRay]

Here is a pictorial of how to do one without the special tool. https://xs11.club/forum/maintenance/...ment-pictorial
Please at least check all the valve clearance measurements before going to anything else. ALWAYS do the simple things first, as they usually fix the problem.

[Radioguylogs]

To check the valve clearances, you remove the valve cover and place the cam lobe directly oposite the shim. Measure the shim clearance with a feeler gauge.

[DEEBS11]

..........

[bikerphil]

By all means, use the special tool if you are not comfortable removing the cams, one mistake with realignment of the sprockets and bent valves may result.

[jkorn]

You will need different pucks to adjust clearance. I wonder if they are still available?.

[bikerphil]

The 29mm shims are still available. Here is the tool after it has been modified...

[cajun31]

I asked in your previous post. How many miles does the speedometer show?

[jkorn]

Why did you modify the shim removal tool. I’ve used mine many times without any modifications?? BUT you need to be VERY careful

[bikerphil]

Why did you modify the shim removal tool

Well, it wouldn't line up properly to hold the shim bucket down, the castings must be different on some. Just poor quality control I guess. Had to elongate the bolt holes too. After all this, works great now.

[ACAL]

The numbers today seemed very off haha. Is it normal for numbers to be this small if maybe previous owners never adjusted the valves? Still seems odd to me that I had decent compression in 1,2,4 and low in cylinder 3. These numbers don’t reflect that much?

[DiverRay]

You will need to correct the clearance on all the valves before you can start to figure out what is wrong. The numbers ARE off by a lot. Once you have the new shims in place. rotate the engine with the starter and the plugs removed for about 20 seconds, and then re-check all the valves. You may need to re-do one or two valves.

[cajun31]

The maintenance manual states that the valve adjustment should be performed every 4000 miles. You have 40,000 miles and no record of when and how often it has been done. Ray is point on and you need to get that corrected. From some of the pictures you posted of the carbs they look clean. They probably will need to be synchronized after you get the valves adjustments in order. Do you have a maintenance manual? If not you need to get one. You can download one from here Ringler.us | Manuals & Resources | Yamaha. You need to use the table on valve adjustment.

[cajun31]

You may be wondering where you can get the shims. Here is one supplier. Valve Shims - 29mm Diameter - 2.00mm to 3.10mm | Yamaha Motorcycle Parts | Mikes XS
They sell them in a kit of 20 as well as individually. They also sell the valve adjustment tool. If you search Ebay there are others that sell them as well. Better to get the kit to start out with. As you adjust you will find that you need many different shims and you can also reuse some of those on the bike on other valve buckets. As Ray stated, once you get them all within tolerance you need to rotate the engine over several times with the spark plugs still removed then recheck all of them again. I don't think it has been mentioned, you also need to do all the adjustments when the motor is completely cooled down. Common sense would dictate that anyway.

[bikerphil]

The old school way to measure the clearances is by using the imperial specs, so, every shim step in size is conveniently .002", everything can be figured in your head. I wonder why they would include the inches specs in the FSM alongside the metric?