My bike wasn't running like it should, so I should take apart my carbs and clean up. After I got everything apart, it looked really clean. I did what I could, but they were pretty good to begin with. While re-attaching them, I noticed that they never had the vacuum hose from the petcock attached. So I bought a new one and hooked it up. I thought this might fix my problems. After a few cranks, it started up but the bike would idle very high and if I adjusted the set screw lower, would not hold idle. No big deal though, I hadn't balanced the carbs yet. I built a vacuum gauge with some hose and a yard stick and adjusted the balance screw so that when it cranks, it appears to be pulling equally. The problem is that now that I've touched that screw, there's nothing I can do to get the bike started again. I've tried fiddling with the mixture screws, but nothing. Can anybody offer some advice?

If your choke is working, your pilot jets aren't clogged, and you have a good battery it should fire right up.

Check your plugs.  They should let you know if the bike is running way too rich or lean.  Also check for vaccuum leaks.  Finally, check to make sure your pilot jets are clear. 

If you can, I recommend taking the bike to a good local shop.  $100 to get the carbs dialed in and the bike running right is a good deal.

The pilot jets were perfect when i took them off in the first place and I still cleaned them with ethanol. So I know they're not the problem. The battery is dead, but I've been jumping it so that shouldn't be the issue. I'm pretty sure the choke works.

I did get it running, but barely. It would not run without the choke on full, idled at 1k and  died instantly when I gently touched the throttle. Something is very wrong. Now it won't start again. 

Juan, do you mean check the spark plugs to see if it's running rich or lean? I don't understand. I would take them to a shop, but I really want to learn how to fix my own bike...so that's last resort.

are you getting fuel now?

no, i don't think so. i'm pretty sure i'm getting spark, so something is borked with the fuel along the way. i still can't get it to start regularly and when it does, it runs very weakly and usually takes a good bit of engine cranking.

i guess i should pull the carbs off again, but they were spotless when i looked the first time. float levels is the only "regular" thing i haven't looked into yet.

turn your pet chicken to prime let it sit for a few seconds and try to start it.

well it's been on primary with gas for about a week now. i've been stuck for a while.   

if youve been on prime for that long your outta gas and or flooded

Quote from: dleemiller on March 10, 2009, 05:10:39 PM
no, i don't think so. i'm pretty sure i'm getting spark, so something is borked with the fuel along the way. i still can't get it to start regularly and when it does, it runs very weakly and usually takes a good bit of engine cranking.

i guess i should pull the carbs off again, but they were spotless when i looked the first time. float levels is the only "regular" thing i haven't looked into yet.

Before you pull the carbs off again, check your float heights. That will tell you if you have gas getting to your carbs as well as making sure the floats are set right. If the float heights are good, try checking for vacuum leaks quickly before you pull your carbs again. You said someone had removed the fuel vacuum hose, perhaps they did it because the petcock was creating a big vacuum leak. If it was missing a hose and running for any length of time, there is probably a reason the hose was gone. Probably not a good reason, but someone probably went through the effort of removing it at some point because they thought it might fix something... Just a thought.

Is any fuel getting to the carbs?  You can crack open the float bowl screws and see if any fuel comes out (pop a hose on it and into a container).  Also while you have a "clear hose" on it, you can check float bowl levels.  You say the vacuum line was off the petcock.  What setting were you running the petcock on when it ran normally? PRIME or ON?

Quote from: fred on March 10, 2009, 06:37:02 PM

Quote from: dleemiller on March 10, 2009, 05:10:39 PM
no, i don't think so. i'm pretty sure i'm getting spark, so something is borked with the fuel along the way. i still can't get it to start regularly and when it does, it runs very weakly and usually takes a good bit of engine cranking.

i guess i should pull the carbs off again, but they were spotless when i looked the first time. float levels is the only "regular" thing i haven't looked into yet.

Before you pull the carbs off again, check your float heights. That will tell you if you have gas getting to your carbs as well as making sure the floats are set right. If the float heights are good, try checking for vacuum leaks quickly before you pull your carbs again. You said someone had removed the fuel vacuum hose, perhaps they did it because the petcock was creating a big vacuum leak. If it was missing a hose and running for any length of time, there is probably a reason the hose was gone. Probably not a good reason, but someone probably went through the effort of removing it at some point because they thought it might fix something... Just a thought.

hm that's a good point.. i'll try checking the float height before i pull the carbs off again. i was thinking there might have been a reason for the lack of vacuum hose. it seems that whoever did the work on this bike before it got to me was pretty competent in the mods they've made. how does one check for vacuum leaks?

the setting from the petcock i've always had to use was PRI. it was never quite clear to me why, but i noticed it from the first day i bought it. 

Quote from: dleemiller on March 11, 2009, 07:39:20 AM

Quote from: fred on March 10, 2009, 06:37:02 PM

Quote from: dleemiller on March 10, 2009, 05:10:39 PM
no, i don't think so. i'm pretty sure i'm getting spark, so something is borked with the fuel along the way. i still can't get it to start regularly and when it does, it runs very weakly and usually takes a good bit of engine cranking.

i guess i should pull the carbs off again, but they were spotless when i looked the first time. float levels is the only "regular" thing i haven't looked into yet.

Before you pull the carbs off again, check your float heights. That will tell you if you have gas getting to your carbs as well as making sure the floats are set right. If the float heights are good, try checking for vacuum leaks quickly before you pull your carbs again. You said someone had removed the fuel vacuum hose, perhaps they did it because the petcock was creating a big vacuum leak. If it was missing a hose and running for any length of time, there is probably a reason the hose was gone. Probably not a good reason, but someone probably went through the effort of removing it at some point because they thought it might fix something... Just a thought.

hm that's a good point.. i'll try checking the float height before i pull the carbs off again. i was thinking there might have been a reason for the lack of vacuum hose. it seems that whoever did the work on this bike before it got to me was pretty competent in the mods they've made. how does one check for vacuum leaks?

the setting from the petcock i've always had to use was PRI. it was never quite clear to me why, but i noticed it from the first day i bought it. 

If you've always used prime on your petcock to run the bike, then it was not modified for non vacuum operation, it was just disconnected from the vacuum system. Was there a cap on the vacuum port that you connected the petcock to? If so, that is a really good indication that someone at some point thought the petcock was leaking...

As for checking for vacuum leaks, it is fun, just get a flammable aerosol and spray it on thing you think might be leaking while the bike is at idle. Just start from the intake tubes and work backwards. As soon as you spray the leaky part, the idle should increase and you've found a leak. Many people recommend using carb  cleaner or WD-40, but both of these substances have been made to be far less flammable over the years, so a better bet is starting fluid. You can get it at any auto parts store and it is insanely flammable, so be careful and don't have too much fun.

mm yes i realized how cool ether was the day i tried to make a flamethrower out of it, like what you can do with WD-40...not a good idea! It is far far more flammable and the flame ran up the stream faster than the starting fluid came out of the can haha.

there wasn't any cap on the vacuum port of the petcock when i got it. i'll give this leak testing method a try once i figure out how to get it started.

Try capping off the vac port on the carb b4 using the aersol.  My petcock has since been converted to a non-vacuum Honda CRF450 style to do away with vacuum issues and the engine didn't run well until the vac port was capped.
Good luck.

finally got this one figured out. i called a guy over to give me a hand with this thing and eventually we tracked it  to the petcock. it seems the thing is partially clogged up so the carbs weren't getting a reliable stream of fuel. i yanked the petcock off and hooked the tank directly to the carbs. it starts fine and idles like a dream.

i was thinking of not buying a new petcock. other than the fact that i wont have access to my reserve, this is fine right?

If you have no petcock and your float needles do not seat or otherwise leak, you will have gasoline in the airbox and on the ground at best, or gasoline in the cylinder and crankcase at the worst.

I failed to notice something before, sorry.  You're supposed to balance the carbs with the engine running at 1750 rpm, not by cranking.  I'd put the screw back where it was and go from there.  Hopefully you kept track of how much you turned it and in which direction.

you did remember to turn the petcock on on the tank back on after you reistalled the tank didnt you?  if thats not it, you may not have as much fuel in it as you think.  try running a gas line directly from the tank, to the carbs, and cap the other one at the petcock, and try that.  if it runs like that, it would indicate a petcock problem

Quote from: bill14224 on April 15, 2009, 04:23:25 PM
I failed to notice something before, sorry.  You're supposed to balance the carbs with the engine running at 1750 rpm, not by cranking.  I'd put the screw back where it was and go from there.  Hopefully you kept track of how much you turned it and in which direction.

Why would it matter what the original setting was?  Since you have it running now (congratulations  )  just rebalance from where it is now.