Valve clearance check

[old_chopper]

I checked my valves this evening and found two intake and two exhaust valves tight out of spec by .001". The others were right on the money. In your experience how much difference will this make? I'm getting shims to correct it but wondered what kind of improvement to expect. The plugs show definitely rich. Carbs are stock XJ carbs with needles shimmed 2 washers. I'm going to put them stock after the valves and a test ride.

[cywelchjr]

The shimming would be likely to make them show rich all by itself. The shimming raises the needle which makes things richer.

[James England]

I checked my valves this evening and found two intake and two exhaust valves tight out of spec by .001".

Presumably, these valves were too tight, yes?

[old_chopper]

Presumably, these valves were too tight, yes?

Yes, .001" tighter than minimum acceptable. The rich condition is puzzling as the bike has free flowing mufflers and pods. The jetting is stock except for the needles being shimmed.

[Fix]

Hard to say. Are the plugs rich at idle, or after a higher RPM chop?

[bikerphil]

The rich condition is puzzling as the bike has free flowing mufflers and pods.

Check your pods making sure there is no protruding lip blocking the air jet in the carb inlet bell. Common problem with some of the pod filters.

Valve clearance off 1 thou isn't enough to make your engine run poorly.

[old_chopper]

Check your pods making sure there is no protruding lip blocking the air jet in the carb inlet bell. Common problem with some of the pod filters.

Valve clearance off 1 thou isn't enough to make your engine run poorly.

I built extensions for the pods to eliminate the lip problem. I have not done a wide open chop or any chops. I'm a little suspect of the pods, they are the cheap-o style. Similar set on my GS550 and it runs great but it's a different bike and has a stage 3 kit in it.
I ordered the shims and when I get it back together I'll take it for a run without the pods to see the result. Currently the plugs are a lot rich. I'm also thinking about the coils, plug heat range (currently BP6ES), and the position of the needles.

[oldnortonrider]

I built extensions for the pods to eliminate the lip problem. I have not done a wide open chop or any chops. I'm a little suspect of the pods, they are the cheap-o style. Similar set on my GS550 and it runs great but it's a different bike and has a stage 3 kit in it.
I ordered the shims and when I get it back together I'll take it for a run without the pods to see the result. Currently the plugs are a lot rich. I'm also thinking about the coils, plug heat range (currently BP6ES), and the position of the needles.

You mentioned heat range, so I'll chime in here. I don't think I've ever seen anything on this forum discussing heat range; I'm amazed at this. For at least 10 years I've been running colder plug range in summer. I actually run "8's" in the middle cylinders (BP8ES), and "7's" on the outside cylinders. Your engine will love you for doing this; and it will run much better after engine is warmed. Colder weather, I either run 6's all way across, or use 6's on middle cyls and 5's on outside cyls. General information here~~the XS650, XS750, XS850 used 7 heat range OEM; some of the models; some may have used 6's. I ride this machine daily; it's my only mode of transportation; daily ride since '95. About a month ago I installed NGK Iridium plugs; running the 8's in middle cylinders; 7's on outside cylinders. ONLY WAY TO GO. Gas mileage increase will probably pay for the plugs; not to mention "all the other 'benefits' ".