Won't start only sputters

[Stoop22kid]

Alright guys I'm lost. I've done everything I know how and I'm not making any progress. I did a complete rebuild from stock to a rephased 750 kit. Has a 277 Pamco. I FINALLY got it to start the other day and ran for about a minute then it shut off. I was so excited I quit for the evening and went to bed. Get up the next day to go work on it again and got nothing. It would just sputter and die. Wouldn't even idle long enough for me to give it any throttle. I'm running bs38s with the stock jets. Then I swapped the jets out for a 145 main and a 30 pilot (which is what someone suggested). I'm still getting absolutely nothing.

So the problems are
-gas coming out of left exhaust pipe
-gas drips out of left carb SOMETIMES
-sputters then dies

The closest I've gotten it to running is when I turn my fuel petcock off and kick it another time or 2.

Thanks for any help you guys can give me.

Justin

 

[XSLeo]

www.amckayltd.com/carbguide.pdf Read this, read this, print it out, read this.
It tells you how to tear down, clean, inspect, adjust and reassemble your carbs.
Pay particular attention to the idle circuits and the enricher circuits.
It started and ran then crud in the fuel system plugged up the idle passages and jets. It also plugged up the enricher jet in the float bowls.
The carbs leaking at any time indicate a tear down and cleaning are needed.
What year are your carbs? They changed them every two years. What works on one set may not work on yours.
Leo

 

[Stoop22kid]

I tore them down and cleaned them but I think I need new diaphrams. I'm gonna take them apart again and try to use some air to blow out the passages. I hope that helps.

 

[XSLeo]

Air helps, I use the tube that comes on the spray cleaner to blow through the passages. If you remove the air mix screws and put the tube in there, cleaner should spray out both the pilot jet and the three holes by the throttle plates. If it don't, there is a plug somewhere.
A fine soft wire can be used to probe the three holes by the throttle plates, DON'T be too aggressive, you don't what to enlarge the holes, just loosen the crud and blow the cleaner through.
Carb cleaning can take several tries to get all the crud out, be patient you can succeed.
Leo

 

[Stoop22kid]

Ok I'll try to get on that when I get off work tomorrow morning. Hopefully this will work.

 

[Stoop22kid]

Update....cleaned the carbs as well as I know how. Checked the floats and they're in spec. Then it hit me....I hadn't adjusted the cam chain. So I adjusted the cam chain until it was flush. Put the carbs back on and it fired right up until I turned it off about a minute later. Turned the switch back on, kicked it again, and now I'm right back to where I was. It only sputters again. I'm still getting gas out of the back of the carbs also. Back to the drawing board.

 

[Brassneck]

Sounds like you're running rich and fouling the plugs. Did you check the plugs after it stopped running? Also sounds like the floats valves aren't closing....may need to check those again.

Try turning in the mix screws to lean out the carbs...I'm not sure what carb set up for a rephase/750 kit would be needed...but perhaps going back to stock size jets and then up from there?

 

[Stoop22kid]

There's a pic of the plug. This is with the stock jets in and the mix screws at 2 1/4 turns.

 

[Stoop22kid]

Also when I got this bike before the initial tear down it was running fine but I realized as I started having these problems that the mix screws were only turned out 1/4 turn. They're supposed to be 2 1/4. What could have been off so bad on a stock bike that the PO had to turn the mix screws in so far?

 

[Brassneck]

Back then, it could have been that the jets were too big and he turned them in to reduce the air/fuel mix. You might try going in a turn or two and see if that helps get it running.

 

[Stoop22kid]

Ok I got it started this morning by playing with the mix screws. It idled for a few seconds then died off. After playing for a little while with the rpms I shut it off. I checked while it was running and I was getting exhaust out of each pipe but once I shut it off only the left pipe was hot. The right pipe was cool to the touch, not even warm. After only a minute and a half of running should the pipes have felt that way?

 

[Brassneck]

What did you do with the mix screws? Turn in/out? You should pull the plugs to see if they are wet after it dies. Both pipes should be getting warm...could be a spark issue on the left side...or still too rich on that side.

Turn the screws in further and see if that helps. Battery fully charged? Have you tested your charging system?

 

[Stoop22kid]

I turned them all the way in the turned the out 1 full turn. This is the plug from the left cylinder after it died

I'm running a capacitor so there is no battery and I've tested the charging system and it all checks out good.

 

[Brassneck]

To me, it looks a bit wet still...try turning in all the way (But not hard, just till it stops).

You might try taking off the capacitor and putting in a battery (temporarily)...to see if that helps as well.

 

[Stoop22kid]

Everything I'm reading (and sorta understanding) is saying adjust the mix screws to get a good idle.....if the mix screws are way in like mine are then I need a bigger pilot jet. So I would need to put my #30 pilot back in and then do the same thing again to get a steady idle while holding a low rpm? Then once it's idling correctly I can time it properly and start working on higher rpm jetting? Is that correct?

 

[Brassneck]

Everything I'm reading (and sorta understanding) is saying adjust the mix screws to get a good idle.....if the mix screws are way in like mine are then I need a bigger pilot jet. So I would need to put my #30 pilot back in and then do the same thing again to get a steady idle while holding a low rpm? Then once it's idling correctly I can time it properly and start working on higher rpm jetting? Is that correct?

Kinda...but backwards.

So turning the screws out, means more fuel, turning them in means less fuel. If you're turning them in, and are still too rich, then you essentially are saying you need smaller jets because the current ones, even when providing as minimal fuel as possible, is flooding the plugs.

IF you were turning them out well beyond the recommended spec, then you would need bigger jets.

So with the mix screws fully seated, can you get it to idle? If so...great...but you need smaller jets. If not, then definitely switch to smaller jets and keep trying.

Also, did you try to put a battery on there, that could be a huge part of the issue as well.

 

[Stoop22kid]

I haven't tried a battery yet....working night shift sucks. I tried to kick it a few times before I came to work and it didn't fire but the left pipe still got warm. And the right pipe still stayed cold.

 

[Brassneck]

You have spark on the left side?

 

[Stoop22kid]

Yessir. Spark on both sides.

 

[Brassneck]

Ok, good...so I'll stick with my thoughts...turn in mix screw and see if it will run when fully seated. If that doesn't work, pull carbs (likely have to anyways) and put smaller jets...

Good luck.