Any ideas on what problem I have on my hands now?

[caj411]

I'd like to thank all you guys for input during the winter about petcocks. I got my old vacuum petcocks replaced with new ones, I can now turn off my fuel and it no longer drips all over my bike. Now......

When I changed the petcocks it was winter, so I was running the cycle in the garage, kicked it about four times and it fired up, as it was warming up, it kind of coughed, wheezed, then it died and fuel vapors came out in a cloud from the carbs. It hasn't fired a lick since. I've checked the plugs, so its getting spark, but not a hint of it firing when trying to start it. When I turned it over the other day I heard some rattle as I let off the starter, do you think I have a valve problem? I was thinking it could be the carb, but this rattle I heard did not sound good.

If so, any idea how expensive this could get? I'm about ready to push the thing over in the corner and just leave it. I've worked on this thing for years and gotten 30 minutes of ride time out of it.

 

[DogBunny]

The rattle is the starter motor gears and is more or less normal. How much work have you done to the carbs -- they are your likely problem. If it fired up once, you should be able to get it to fire again. Kick the bike a few times with choke on, then pull a plug. Is it dry, soaked, in-between?

 

[caj411]

Back in December it was in the shop for a little work and they replaced the carb floats and gave them a look, so I would hope they would last longer than 30 minutes before a problem. I'll have to turn it over and pull the plug to see if its wet. I didn't think of that I was just looking for fire, which I got. I'll give that a shot tomorrow and report back. I could pull the carb, but unless something were obvious I wouldn't trust my competence. I could soak it in a can of carb cleaner. lol

 

[DogBunny]

The carbs can be a bit complicated for a first timer. "Replacing the floats and giving them a look" is not going to cut it. There is plenty of info on this Forum, and lots of members who will help. You've gotten this far, now you have to bring it on home and tackle the carbs yourself. It is unlikely that your typical shop will give you satisfaction.

 

[gggGary]

Outside of the garage, dry the plugs GOOD with a propane torch. Then try to restart it.

 

[caj411]

Is that to burn off any residual carbon buildup on the plugs? They have about 30 minutes total run time on them and they were giving me spark when I pulled them, but I'll give it a shot anyway. My fuel lines are clear, so there is fuel flowing, the question is how much and where is it going?

 

[DogBunny]

If I can read gggGary's mind, I think he was assuming that your plugs were fuel soaked, and was telling you how to dry them, not clean carbon off of them.
I suggest you do this:
Starting with dry plugs, kick the bike a few times with choke on, then pull a plug. Is it dry, soaked, in-between?

 

[5twins]

To clean fuel fouled and soaked plugs, you can use electrical contact cleaner. Spray them, scrub a little bit with an old toothbrush, spray again to rinse and let dry. The contact cleaner evaporates quickly so the plugs are ready to go again in just a few minutes.

Years ago, me and my buddies all rode 2 strokes. We fouled plugs all the time so we all had several extra sets. Back then, we weren't aware of the contact cleaner so we just scrubbed the fouled plugs with clean gas. Then they had to air dry over night before we could use them again. If we would have discovered the contact cleaner back then, it would have been a revelation, lol. The ability to clean and re-use them in a matter of minutes would have been terrific.

 

[gggGary]

Yeah can't count how many times I've had a "should run" engine come to life after torching the plugs. Seems like a back fire or back spin like you experienced can foul the best looking plugs. I try to have everything else ready and start cranking as soon as "cooled off enough to install", hint; gloves, plugs are in. Never hurts to spin it through a for a while when the plugs are out either.

 

[XSLeo]

For a new guy working on carbs you should read the carb guide. www.amckayltd.com/carbguide.pdf
it gives you detailed steps to tear down, clean, inspect, adjust and assemble your carbs.
Pay particular attention to the idle circuits. They have tiny passages and ports. These all need to be very clean.
The rest of the carb is fairly easy. Big passages and ports, easier to get clean.
Leo

 

[caj411]

Yeah can't count how many times I've had a "should run" engine come to life after torching the plugs. Seems like a back fire or back spin like you experienced can foul the best looking plugs. I try to have everything else ready and start cranking as soon as "cooled off enough to install", hint; gloves, plugs are in. Never hurts to spin it through a for a while when the plugs are out either.

Dude! That worked like magic. Torched plugs, first kick she fired up. I can't believe it. I'll pull them again and give them a good cleaning later. You saved me from pulling out all of my hair and loosing my mind, as well as my money. Thank you!!!!

 

[caj411]

Thanks so much for the advice guys. I really couldn't have finished this build without this forum.