Valve Adjust Issues

[Ccitis]

I was using a different members thread to learn about Valve adjustment... I now have some issues to troubleshoot. I just recieved my shims from Mikes XS. Upon install, the clearances are WAY out of wack... reading similar to what I started with...Numbers below. I tried rotating the cam up to 10 times to seat. Helped with some, not others. Most are .05 to .10 larger gap now, and that should be apparent. As well, I am concerned, I see some flaking on the top end after rotating the cam shaft... it appears the edges of the exhaust cam lobes are flaking a little bit. I see a little bit of metal on the top end, and a rough edge on the lobe. What is up with that? Why would that be occurring. I am using a wire to trap the valve for shim addition and removal. Any help is appreciated. I am totally baffled, as I have done lots of valves before (never shim over bucket)... and had to order these shims from the US... how can they be unchanged with a new shim? Will they bed in with running? I measured all shims too, they are correctly stamped.

Ex 1 Measured at .13.
Shim 295
New Shim 285
New Measure .23 in spec

Ex 2 Measured .21
Shim 290
New Shim 285
New Measure .26 A tad loose, but fine

Ex 3 Measured .19
Shim 290
New Shim 285
New Measure .22 barely in spec

Ex 4 Measured at .18
Shim 290
New Shim 285
New Measure .19 NOT in spec

In 1 Measured at .10
Shim 280
New Shim 275
New Measure .09 LESS than with the old shim

In 2 Measured at .10
Shim 280
New Shim 275
New Measure .10 NO change

In 3 in spec at .14, no change

In 4 Measured at .07
Shim 285
New Shim 280
New Measure .16 .1 loose...but how with a .05 shim

[Radioguylogs]

Perhaps some of those unidentified metal flakes got under the shim?

It is also possible the oil film under the new shim is thicker.

Maybe try removing and cleaning the new shim and the shim bucket surfaces?

I am thinking that using a wire to hold the valve open may make some loose carbon, but the crud would be on the combustion side of the bucket and it could only make the shim gap bigger if it prevents the valve from closing.

[Ccitis]

Yeah I took em all out and I think I sorted it. Number 2 intake is a touch tight still, I can just get a .13 in... but I am going to call it... I think it will bed in. Thanks man...

[bikerphil]

Next time try measuring in thousands, each shim size increment is .002", so just add or subtract what is needed. Super easy and less confusing this way. JMHO

[DiverRay]

You could have had carbon on the valve face, and it "went away" when you changed the shim. Notice a few of the valves now have a smaller clearance than they should. Previous owner was probably running premium fuel, not regular the bikes are designed to run on. That causes a LOT of carbon build up. I would think about doing a de-carbon on the engine and then measure the valves once again. See what and how much has changed.
To de-carbon, Just ride for a little bit until the engine is warm, then with the air cleaner off, spray Berryman's B12 Chemtool into the carbs. Go across all four until the engine dies, let it set for 20 minutes, and start it again. Rev it just a little and it should be good.

[Ccitis]

You could have had carbon on the valve face, and it "went away" when you changed the shim. Notice a few of the valves now have a smaller clearance than they should. Previous owner was probably running premium fuel, not regular the bikes are designed to run on. That causes a LOT of carbon build up. I would think about doing a de-carbon on the engine and then measure the valves once again. See what and how much has changed.
To de-carbon, Just ride for a little bit until the engine is warm, then with the air cleaner off, spray Berryman's B12 Chemtool into the carbs. Go across all four until the engine dies, let it set for 20 minutes, and start it again. Rev it just a little and it should be good.

Interesting comment. I run 94 octane in all my old Carb bikes because it has the least amount of ethanol (allegedly). I am in Canada. I ended up getting the clearances to a place I was good with and buttoned her up. Started for the first time this year, with throttle it is backfiring or popping on one side... would make me think it is lean. I have had this before when it was on enrichener. Now it is doing it with a touch of throttle, sounds like one cylinder is missing. More troubleshooting before its on the road I suppose.

[DiverRay]

I'm lucky that Idaho has ethanol free regular gas for sale in a lot of stations. It's for "small engines", but cost the same as premium. In California, I just ran regular with ethanol. As I could ride almost all year, it wasn't such a big deal. Ethanol fuel will turn after only a month in a motorcycle tank.

[Ccitis]

Video of my running issue... notice when I blip the throttle it is running very rough and popping.
https://www.youtube.com/watch?v=bkD0g2hx2Tk

[oldyam80sg]

I watched your video-what condition are your vaccuum caps in? They do get cracks in them and need to be replaced.

[Ccitis]

I watched your video-what condition are your vaccuum caps in? They do get cracks in them and need to be replaced.

Brand new, and zap strapped on. Its a good point though, it is very similar symptoms to losing a vacuum cap. The intake boots are new too. FWIW.

[oldyam80sg]

Have you done a carb sync? Doesn't sound bad. I would run some Techtron in the tank.To see if a cylinder is missing, I would use an infrared thermometer and check that way. That is more accurate than the spritzing water test. Also are the plugs new? They could have some crud on them and cause the misfiring. Look at the condition of the plugs.

[Ccitis]

Yeah, I have synced them last year. I will check again. Plugs are new enough and in good shape. Just had a look when the valves were done this past week. Light brown.

[DiverRay]

Part of the valve adjustment IS to re-sync the carbs. When you change the valve lash, you change how the piston pulls air.

[Ccitis]

Started the bike today and it popped once, but ran fine. Decided to take it out for an hour and blow it out a little bit. Ran really well, pulled hard, idled great. Coming off throttle I am getting some hisses, small burbles and pops... a little more than I would like... but it was running good. Put a bunch of seafoam in too.

[DEEBS11]

Turn open (counter clockwise) each of your four pilot screws 1/8 of a turn to richen the pilot circuit. You are a little lean on the pilot.