I'm Stumped

[mrhedges]

After my month long tour this summer I put the bike up to fix some oil leaks. When I finally got it back together it seemed to run fine but after a short trip around the block it started dying with any throttle. I figured it was time to clean the carbs again because the bike sat (even though I thought I filled it up with non-ethanol gas) . I followed the procedure outlined on the forum and even replaced all the orings again (from the O-ring guy everyone recommends). Again bike starts fine. I run it for a bit. Even ride my GF around the block. Seems to be running normal but hanging a bit after I let out the throttle. I figure it just needs the carbs synced and maybe the valves checked. I go back a couple days latter to start it again and it won't start.

I check compression next. 135 PSI and each cylinder. Its sparking. I check the battery and decide to charge it after it's charged I use starter fluid just to see if I can get it to fire. Fires right up but again it dies with any throttle and the idle is all over, going up and down. Now to be honest I haven't checked the valves in a year and in that year I put atleast 6k miles on the bike. Could that be the issue? If the valves were off would that effect compression? Or is this still a carb issue? I guess I could have made some mistake with the carbs but I followed the directions.

I have checked the airbox and the airbox seems fine, I replaced the rubber around the box just to be sure.

I'm stumped!

[bonanzadave]

Check the easy stuff first. Did you try running it on PRI ? Vac or fuel line kinked ? Gas cap vent plugged ?

[mrhedges]

Check the easy stuff first. Did you try running it on PRI ? Vac or fuel line kinked ? Gas cap vent plugged ?

I did try to run it off PRI, I should check the Gas CAP vent.

[cowboyup3371]

Do your valve adjustment as it is time. How are the intake boots - do they show any signs of cracking or anything that would indicate a vacuum leak? How about posting the results of Posplayer's quick test here so we can see the condition of the battery/charging system?

[Brendan W]

I'm with bonanzadave on this.
Sounds a lot like fuel starvation and that's real easy to check.
Does fuel flow on PRI and how much ? Run it to a jar.

[mrhedges]

I'm with bonanzadave on this.
Sounds a lot like fuel starvation and that's real easy to check.
Does fuel flow on PRI and how much ? Run it to a jar.

Oh, it flows, it drips all over the sidewalk if I leave it on. So I'd guess its not a clogged vent right?

I have replaced both the intake and airbox boots recently. I will check to make sure they are all properly tighten.

The battery reads 12.55-12.6 just sitting, it reads 12.12 with the key turned on but the bike not running, running the battery reads 13++. So the stator seems to be working. The battery will drain to 12.3 after about 6 tries of starting it. Battery might be on it's way out, I have drained it down and recharged it a bunch of times now trying to troubleshoot.

Thanks for the help. Still curious if it's the valves and if that would effect the compression readings?

[Gorminrider]

Thanks for the help. Still curious if it's the valves and if that would effect the compression readings?

nothing in your original post suggests a serious valve problem...per your compression readings it's unlikely they'd all be equally mal-adjusted so much unless the cam chain has skipped.....but this

Oh, it flows, it drips all over the sidewalk if I leave it on

definitely suggests a fuel problem...specifically, the floats and needles or even a petcock diaphragm problem if it's from the petcocks vacuum hose.

I think you'll have to tear the carbs off and redo.... I always turn the carbs upside down and blow through the fuel inlet as a preliminary test (with more than one carb it's ez to tell if one has leakage potential versus the others) but bench test with a fuel tank attached before putting them back on the bike.

[mrhedges]

nothing in your original post suggests a serious valve problem...per your compression readings it's unlikely they'd all be equally mal-adjusted so much unless the cam chain has skipped.....but this
definitely suggests a fuel problem...specifically, the floats and needles or even a petcock diaphragm problem if it's from the petcocks vacuum hose.

I think you'll have to tear the carbs off and redo.... I always turn the carbs upside down and blow through the fuel inlet as a preliminary test (with more than one carb it's ez to tell if one has leakage potential versus the others) but bench test with a fuel tank attached before putting them back on the bike.

I should clarify that it's leaks when its left on the PRIME position. It does not leak on the ON position.

[Brendan W]

I should clarify that it's leaks when its left on the PRIME position. It does not leak on the ON position.

Float needles should be stopping that.
They could be worn or have dirt stuck in there. This would let the fuel level go too high and run the bike rich.
Could also be pressure in the tank if the vent is blocked. Rock the bike and see if you can hear a hiss from the filler cap.

[Steve]

I should clarify that it's leaks when its left on the PRIME position. It does not leak on the ON position.

For the carbs to overflow, you need to have TWO failures.
1. The petcock needs to flow fuel when not being asked to do so.
2. A float needle in a carb needs to flow fuel when not being asked to do so.

In the case of #2, it might be the needle itself or it might be leaking around the needle/seat assembly, probably due to a faulty o-ring.

In your case, you have shown that the petcock evidently does stop fuel flow, but you have one or more carbs that are also letting fuel flow.

.