Bike wont start after carb rebuild

[Guest]

So here is the story, I got that whole trailer of parts and I am putting a bike together for my brother.

I rebuilt the carbs dipped, soaked, new rings and floats set to factory setting. The sometimes doesn't start and sometimes if I if I crank and crank and crank will finally hit then eventually start. I pulled the plugs they are a little rich looking but not the worse I've ever seen. Great spark, battery voltage is 12.8 with key off, so I am leaning to the carbs again. I don't know if its dumping too much gas and flooding, I pulled the plugs and cranked, fuel shot out of the number 1 spark plug hole then the bike hit and hit and hit then finally started. Carbs were vacuum synced also with a sync tool. I cleaned the ignition advance and lubed the springs incase they were stuck. petcock runs great when vacuum is applied I'm at a loss why this wont start. When it does start (very rarely) it seems to run great and will rev to 8k without a miss. Valves are all within spec I need some help so I can get this damn thing out of the garage and start on my new project.

[azr]

what bike are we talking about here?

[gs11ezrydr]

If fuel is shooting out of the plug holes ,Check the oil level and see if it's full of fuel. Possible crankcase is full of gas. Sounds like a float sticking or not shutting off. Bike run before you messed with it? Check compression May need shimming or adjusting depending on what bike your talking about. Did it start long enough for you to sync. it properly?

[Steve]

1. What bike?

2. How did you do a vacuum sync if the bike won't start?

3. Have you adjusted the valves?

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[TxGSrider]

How were you able to pull the plugs out, with fuel shooting out of the #1 plug hole, then get it to "hit and hit and hit" and start with the plugs removed?

Im just giving you a hard time. It sounds like you have a sticking or dirty float (or floats)... at least that's where Id start checking.

[Steve]

How were you able to pull the plugs out, with fuel shooting out of the #1 plug hole, ...

I was sort of wondering that, too. If the plugs were out, there would be NO suction on the intake stroke, so no way to suck air (and fuel) through the carb.

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[Gs1000g]

Sorry for the miscommunication
its an 1982 gs850L
The bike wouldn't start I pulled the plugs and cranked and gas shot out of the #1 cylinder. Once I placed the plugs back in the bike started and I was able to do a vacuum sync. The air screws are 2.75 turns out. Once the bike is warmed up it seems to idle fine it just does not want to start once it's cold.
I guess the carbs are coming apart again and I will review what I found
the crank is not full of gas I already checked that.

[TxGSrider]

These guys are sure better versed on these than I am, but it seems whenever I forget to switch mine from "Prime" to "on" and it sets for awhile, its usually cylinder 1 that gets the brunt of the extra gas. The bike leans that way on the kick stand and fuel runs to that carb 1st through the common vent tube. So it could be all of the float valves or just one causing the problem. If you get it started it'll probably run like crap on 2 or 3 cylinders (cold) then as it runs and warms up cylinder 1 probably dries out enough to start working and it runs ok.
I mean it could be a valve lash problem or weak spark, but it sounds like a leaky float valve to me. Also, be sure to switch it from "PRI" to "ON" after you get it started, or it can REALLY fill up the cylinders and crankcase with gas (trust me-lol).

[Steve]

Don't do the carbs again, ADJUST THE VALVES.

Unless you really like doing the carbs, then you could go ahead and do them, then come back to a bike that STILL won't start because the valves are too tight.

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[azr]

Good advice on the valves especially for a bike that is unknown to you. While you're in there check the cam timing to make sure no one else has been in there and messed something up.

[Carter Turk]

He mentioned all the valves were in spec in the first post.

[Gs1000g]

I think Figured out the bike today
i always like to put an ending on my post just incase a fellow bike rider had the same issue.
So given that the valves are within spec, I looked back to the carbs. Since I've had them off a million times what's another?
i tried to see if the carbs would be changed when I pull open the choke and it wasn't. Given the condition of the plugs (rich) it seemed like it was getting too much fuel. I looked and 3/4 carburetor O-rings were split in some way. So new o rings and a cleaning I put the carbs back on. The idle kept hanging, I started at 3 turns out on the A/F screw. Still hanging idle long story short it's 2.25 turns out the bike revs idles and runs quite well. I hope if someone is having this issue can read this and it will get them in the right direction.