Shim clearances for both my exhaust valves was <0.03mm, so I re-shimmed to these: Lin - 0.08mm, Rin - 0.03mm, Lex - 0.09mm, Rex - 0.11mm. When I took these I cleaned the oil from each bucket. After buttoning it back up, I set to half choke and it started on the very first crank. It's never started so easily and cylinders fired nice and even, so it looks like the valves are working better. However, idle was a bit low so I adjusted the idle screw some and toggled the choke and throttle to bring it up. Over the span of 90 seconds, it warmed up nicely so I gave it some throttle. The idle when went high to 5000rpm, so I adjusted the idle screw again and it dropped and stalled. I took the tank off and noticed two mistakes that I made: (1) I had the main tank cut-off switch turned off so it was pulling fuel from the bowls, and this explains why it stalled. (2) I hadn't reattached the choke cable properly.

So I fixed both of them and put the tank back on. Crankety-crank, nothing. So I pull the plugs and they're dry. I have blue plug sparks and fuel in the bowls again. Strong airflow coming out of the spark plug holes and airbox when I turn it over. All vacuum hoses are connected. Now 30 minutes has elapsed. So I put it back together and start it again and it fires four times, but stalls again. I put the petcock on PRIME and wait ten minutes, it fires four times again and stalls. So I put petcock back to ON and try once with idle screw totally shut, once with idle screw at 2 full rotations, and once at 4 rotations. Crankety-crank, nothing. Now the battery has dropped to 11.6v. So I push start, nothing.

It started right up on the first shot, so I doubt it's the valve clearance. I can see how the choke cable and idle screw being wrong would make for a rough start, but why did the RPM's rise on first start? Maybe I flooded it and killed the battery on the subsequent attempts. My real fear is that my clearance measurements weren't valid somehow, and after warming up with the new shims, the clearance opened too far and the valves won't allow it to start. I'm lost. Any advice?

UPDATE!:
This problem has been fixed and it's running much better. This problem was caused by these three problems:
- Choke cables were under tension. I must've yanked them while pulling the valve cover. This is why it idled high.
- I had my main fuel switch set to [off], so the engine started using fuel in the bowls, then stalled when it ran out.
- Battery became discharged from trying to start it too many times. This is why I couldn't start it after fixing the fuel switch.
After fixing all of these, I could really feel the difference that the shim job made: the bike runs real nice. Starts up on very first click of the starter, faster warm-up time and throttle response, more torque, and both cylinders have compression numbers closer to eachother. Thanks for all the helps guys, only took me 8 hours of time to do this job, but it's well worth it.

There are a couple of members who set their exhaust shims with 0.13mm clearance.

Is fuel flowing freely? I'd make sure first of all that all the lines are connected correctly to where they should be, then make sure that none of the lines are pinched and reducing fuel flow,  then I'd check there's fuel in the float bowls.

Chris

Yep, as stated above, fuel is running into the floats and nothing is pinched. And It was going into the cylinders too because it started at one point.

ok cool

Quote from: Darkstar on January 20, 2017, 08:47:45 AM
but why did the RPM's rise on first start?

Because it's supposed to do that. By trying to adjust the idle speed while the choke is on, you set it too low and caused the issue.

Here's how it should work:

1. apply choke, start the bike cold
2. don't touch the throttle!!
3. after it starts and runs a few seconds (up to maybe 20?) it should idle up to around 5,000 rpm.
4. let it run at the "fast idle" speed (like 4-5K) for a minute or so.
5. reduce choke to like 1/2 so the idle comes down to like 2K and then you can go ride.

DO NOT try to set the idle SPEED until the bike is FULLY warmed up. By FULLY I mean like 10+ minutes of actual on-the-road riding. Two minutes in your driveway is not even close. You may have to nurse the idle until it is fully warmed up.

If you do this right then it'll start right up with full choke and no throttle when cold and then run itself up to ~5K rpm for the fast-warm-up and then the idle speed will settle back to 1300 rpm once the choke is off and it's fully warmed up. But IME during the first few minutes of riding while it's not FULLY warmed up, the idle speed may vary between like 900 and 1500 rpm if it is set correctly.

Quote from: mr72 on January 20, 2017, 11:57:35 AM
By trying to adjust the idle speed while the choke is on, you set it too low and caused the issue.

Thanks. I think I see what happened. Right before changing the shims, the valves clearances were really tight causing it to stall, and to compensate for that I had my idle set higher than normal to keep it running. So, when I put the new shims in, the valves were corrected, but the idle was still set high, and when it started and warmed up, the idle RPM's were now high. But before I could adjust it properly, it ran out of fuel because my main fuel line was closed, but I didn't know it because it was pulling fuel from the bowls, not the tank. Then I cranked it too many times, discharging the battery, so it wouldn't start even after I corrected the fuel. What a clusterfawk.