Desperate Carb Help Needed!

[teet]

Hi all,

Well...still having trouble with my carbs and new exhaust. Some info can be found here about my previous efforts.

http://www.thegsresources.com/_forum/showthread.php?t=146895

Well..I started today by reinstalling the carbs after verifying their cleanliness, and setting the fuel screw to 1 turn out from bottom, and the same with the side pilot screw..1 turn out from bottom. Plugs are new and gapped correctly, I checked the points, all good. The valves were adjusted this spring, and until this 4 into 1 exhaust (unknown with baffle--pretty quiet)was put on, she ran really well with the stock, rusted out exhaust, and UNI pod filters. The po had 110 mains in the carbs, and the pilots are 15.

I got it all buttoned up, primed the carbs, and she fired right up on full choke, and sounded really good, I thought I bumped the choke off, but the cable moved, and the actual plungers did not. This is where my trouble began. It seemed to run really well, so I took her up the road and back, maybe 1/2 mile, and she started to die, so I pulled the choke cable to realize it was still on. Soooo....rolled it into the driveway..pulled the plugs..all black and sooty. Cleaned em put them back in, and tied to fire her up, and no go...Ive been tweaking the screws for the last hour just trying to get her to start....in 1/4..out 1/4...nada. It will start momentarily on full choke if I turn the petcock to prime, but then will slowly die out...

What the heck am I doing wrong? Are these 110 jets really making that much of a difference? The PO only had the fuel crews out 1/2 to 3/4 turns from bottom, and same with the pilot screws....

I'm starting to get frustrated..I might just stick the crappy exhaust back on, set the carbs back the way the po had itso I can at least ride it..ugh

Any ideas?? I was going to get some jets from Z1 today, but I was advised I could simply tune it??

Thanks all for listening to my rambling..ugh

Jeff (teet)

[DanTheMan]

This may seem like an obvious, stupid question, but I've done this, and I'm sure other people have too. Check your petcock vacuum line. Is it hooked up? Is it cracked? It'll do all that you've described. It'll make you think all kinds of things have gone wrong........

[teet]

This may seem like an obvious, stupid question, but I've done this, and I'm sure other people have too. Check your petcock vacuum line. Is it hooked up? Is it cracked? It'll do all that you've described. It'll make you think all kinds of things have gone wrong........

Thanks Dan!

I just ran out and verified that it is on, and in good shape. I checked it over while the carbs were off. The petcock is new, 2 weeks ago, but it worked fine with the old exhaust on. There are 2 other "vacuum?" lines similar to the petcock one that just hang down with the overflow tubes, does that sound correct. I dont remember them being connected to anything before? They are on the far rt, and left central carbs.

Thanks Dan for helping...my frustration level is rising

Jeff

[Dave8338]

If it ran with the choke on (though with some trouble on the return trip) I would suggest that you are right on the bubble as far as the tune was concerned. Are you sure that you have the plug wires back on, in their correct locations? (I've done it)

You may have just fouled the plugs to a point that they won't fire.
Also with all the cranking. how's the battery charge? Fix the moving choke cable, charge the battery and reset the screws to 1 turn out and retry...

[DanTheMan]

I'm not sure about the other ones, I'm going to have to look on my bike later today when I get up the drive to work a little. This Lyme disease business keeps me tired out before I start doing anything.

[teet]

If it ran with the choke on (though with some trouble on the return trip) I would suggest that you are right on the bubble as far as the tune was concerned. Are you sure that you have the plug wires back on, in their correct locations? (I've done it)

You may have just fouled the plugs to a point that they won't fire.
Also with all the cranking. how's the battery charge? Fix the moving choke cable, charge the battery and reset the screws to 1 turn out and retry...

Good tip Dave,

Thankfully, I pulled the plug wires one at a time, so they are in the correct locations.

I'm going to go out and pull the plugs again, and give them a good cleaning. I pretty much drained my battery trying to get her re-started, so its on the charger right now.

Thanks....I'll report back..I'm still undecided if these jets are too small??

Jeff (teet)

[renobruce]

Thanks Dan!

I just ran out and verified that it is on, and in good shape. I checked it over while the carbs were off. The petcock is new, 2 weeks ago, but it worked fine with the old exhaust on. There are 2 other "vacuum?" lines similar to the petcock one that just hang down with the overflow tubes, does that sound correct. I dont remember them being connected to anything before? They are on the far rt, and left central carbs.

Thanks Dan for helping...my frustration level is rising

Jeff

The lines you are referring to are vents, and they don't hook up to anything. If you are running pods and/or aftermarket 4-1, you need to remove the tubes from the nipples. The vent tubes are on carb #2 and #4. Your petcock should be hooked up in between the vents, carb #3.

Changing the main jet is not going to effect how it runs at idle. You should be fine with the #15 pilot jet. I would set the side air screws at about 1 1/2 turns and the pilot fuel screws underneath at about 1 turn. Are you certain the float height is set correctly?

[renobruce]

Oh, and also, you need to make sure your choke circuit is fully closed after starting it. If it is left hanging open, it will bypass the function of the pilot jet.

[teet]

The lines you are referring to are vents, and they don't hook up to anything. If you are running pods and/or aftermarket 4-1, you need to remove the tubes from the nipples. The vent tubes are on carb #2 and #4. Your petcock should be hooked up in between the vents, carb #3.

Changing the main jet is not going to effect how it runs at idle. You should be fine with the #15 pilot jet. I would set the side air screws at about 1 1/2 turns and the pilot fuel screws underneath at about 1 turn. Are you certain the float height is set correctly?

That sounds right, so I can just pull those hoses off to expose the "nipple"?? Yup the petcock is hooked up to carb 3.

I dont know about the float height? I just pulled the bowls to check the mains, and didn't touch the floats. Would the height need to be adjusted for a different exhaust?

I will reset everything and try again when my battery has some more power. I pulled the plugs and they were sooty black. I cleaned them again and checked the gap .025 .

I will idle very choppy like and very slow with the choke on now, but dies after 10 sec. If I push the choke in after it fires up momentarily, it dies instantly....hmmmm

I hate working on carbs...ahhhhhhhhh

Thanks renobruce...appreciate IT

Jeff

[renobruce]

Kind of obvious, but have you cranked in the idle adjust knob to raise the idle rpm's? And it still won't run? If you can just get it to idle, you can then fine tune your side air screws. Turn each one to get the highest rpm's. Re-set the idle knob if needed.

If you have never checked the float heights, you need to. You can't trust someone else's work.

[teet]

Kind of obvious, but have you cranked in the idle adjust knob to raise the idle rpm's? And it still won't run? If you can just get it to idle, you can then fine tune your side air screws. Turn each one to get the highest rpm's. Re-set the idle knob if needed.

If you have never checked the float heights, you need to. You can't trust someone else's work.

Thanks..I tried the idle knob to no avail. I just reset the air screw to 1.5 turns out, and the fuel screws to 1 turn out, and now it just cranks...nothing.....

I guess I'll have to pull these f-ing carbs again....and figure out how to check the float height...

Why does adding a simple exhaust that probably has way more back pressure than the stock one, cause so much greif?

Thanks...

Jeff

[teet]

Well...I guess I'm gonna give up on her for a while..I'm at a loss. Ive tried every position imaginable for each screw, and now she wont fire at all....fuel is flowing, and spark looks good...still not even a sputter.

I dont think changing jets at this point will do any good if I cant get her to start at all. I should have left it alone..ugh

Wish someone was close to me that has some experience with this stuff...

with my luck I'll take her to my zuke dealer and $500 later she'll be kinda running ok..been there done that before.


UGHHHHHHHH......

Jeff (teet)

[renobruce]

I don't think the reason your bike won't start is related directly to the pipe. Changing the pipe might make it run richer or leaner, but it should still start and idle. If you are certain that the spark is good, gas flow is good, no intake leaks, etc. and you haven't changed or done anything else, then it's probably carb related. You need to take the carbs apart and clean them and set the float heights. If you are not able to do that yourself, send them to me and I'll do it for much less than you stealership will.

[teet]

I don't think the reason your bike won't start is related directly to the pipe. Changing the pipe might make it run richer or leaner, but it should still start and idle. If you are certain that the spark is good, gas flow is good, no intake leaks, etc. and you haven't changed or done anything else, then it's probably carb related. You need to take the carbs apart and clean them and set the float heights. If you are not able to do that yourself, send them to me and I'll do it for much less than you stealership will.

Thanks...I think its related indirectly. Probably by running it around with inproper tuning..only a guess though. I'm thinking I may have made another possible problem more "visible".


I checked the intake boots yeterday, and they are in great shape, soft, pliable, and the orings behind them are new.

The spark looks good to me..its bright, and quite visible with a good "kernel"..

I always hesitate to work on carbs because of the delicateness, and how easy it is to screw things up...I guess I should just jump in. Its my lack of experience that makes it frustrating...I for-see myself spending umpteen hours working on thees things just to find out Ive made it worse...

I'll try to find some info about float height and start there. I appreciate you offer, and support.

Jeff (teet)

[renobruce]

Remove the bowls, flip the carbs upside down, remove the gaskets, and measure the height at the highest point. They should be 24mm. Go to the GS Garage for a tutorial on cleaning the VM carbs. It's not that hard, and really not much you can "screw up".