Carb issues

[Titbit21]

I recently cleaned and replaced all the jets and needles in my carbs, and adjusted the floats. My problem is when I put it together the bike seemed to run really lean on the 1 and 2 cylinders, and rich on the 3 and 4. It barely runs. Could this be caused by the air/fuel mixture screws? Everything seems to be clean in the carbs, and the replacement jets were the same #'s as the previous ones. What causes this? I really tired of watching all the bikers ride by and not being able to join them.

[CatatonicBug]

Yep. Either it's your mixture screws or you have a vacuum leak somewhere.

[Titbit21]

So I should turn out the #1&2 mixture screws if they are lean? I hooked up my synch tool and I'm a bit off there so I am going to make some adjustments to that before I will mess with the mixture screws. As far as vacuum leaks I think I might be ok. The boots are not the best looking but I put a bunch of sealant around them.

[DGXSER]

First check that your getting fuel to the lean ones. Is a fuel line kinked? Is the petcock on? is the gas tank really low on fuel where one side might not be getting enough?

Now, if you know you have good fuel flow to both sides, and the problem persist, then check the mix screw settings. For a stock setup I tend to start at 2 turns out form lightly seated. After it gets running decent you can start tuning mixtures.

[Titbit21]

First check that your getting fuel to the lean ones. Is a fuel line kinked? Is the petcock on? is the gas tank really low on fuel where one side might not be getting enough?

I got the lean ones to start having more soot on the plugs, so that is starting to look better. And I just went and picked up another 2 gallons so i will have enough gas. The fuel lines are not kinked. I guess Ill be tinkering around some more till the sun goes down.

[mack]

If it's running

like that above idle, are you sure that the c clips on your needles are all set in the same position?

[Titbit21]

So I had to walk away from this bike before i burnt it, so now im back at trying to figure this problem out. No matter what i had tried, nothing has changed the problem with the one and two cylinders. They are still running lean/hot. So let me describe the problem when it first started and maybe that will offer give somebody an idea of whats going on.

Last summer i went out to start my bike and noticed gas coming from the air box ( i have had a issue with stuck floats). So i cleaned out the filter, tapped the floats and started the bike. I rode maybe two miles until something happened to where the bike was only running off of three cylinders, or at least it felt like that. Tried starting it later and a big backfire happened, so...

Since then i have replaced all jets, needles, ect. I put the carbs back on the bike started right up, but has a third of the power its suppose to have, and runns hot on 1&2 cylinders. Pulled carbs again, cleaned the fuel and air T's that plug into them and problem still there. No pulled carbs off again, cleaning again and blowing out ports with compressor. Everything seems to be open and clean. So my question is, when i get this POS back together, if the problem is still there what should I focus on now?

[JeffH]

Since then i have replaced all jets, needles, ect. I put the carbs back on the bike started right up, but has a third of the power its suppose to have, and runns hot on 1&2 cylinders. ?

Just a whacky thought??
Where did you get the Jets?? From what source?? What brand?? Confirm what size since you earlier said 'with same size'?? Same for the Needles since you say they are new too .......

-and- bike is a stock 1978 11E?? If all carb parts 100% new it wouldn't explain #1 & #2 running super hot, but what parts you used might be a good place to start a troubleshooting discussion.

-and- you have tried the WD40 or propane test on the manifold boots to see if rpm changes indicating air leak on the intake?? Sparks Plugs in #1 & 2 white? with #3 and 4 tan?? Finally, will it at least idle smoothly at a consistent rpm?? If so, what rpm?

I might have missed some earlier discussions -but- what problems were you chasing when you decided to change all the Jets and Needles?


Jeff

[Titbit21]

Just a whacky thought??
Where did you get the Jets?? From what source?? What brand?? What size??

-and- bike is a stock 1978 11E?? If all carb parts 100% new it wouldn't explain #1 & #2 running super hot, but what parts you used might be a good place to start a troubleshooting discussion.

-and- you have tried the WD40 or propane test on the manifold boots to see if rpm changes indicating air leak on the intake?? Sparks Plugs in #1 & 2 white? with #3 and 4 tan?? Finally, will it at least idle smoothly at a consistent rpm?? If so, what rpm?

I got the carb kits from george fix K&L if i remember correctly. All the numbers were the same as the old ones. I compared the old with the new when i put them in. The bike is bone stock. I have made an effort to rebuild it that way.

I havent tried the wd40 trick though. I should have but didnt. But everytime i take off the carbs i put some silicone sealant all around them to avoid having leaks. And as far as idleing smoothly, that doesnt happen. When i mess around i get it to idle at 1k. when you pull on the throttle, it revs up but rough and not as fast as what it did last year. I rode it .3 miles and it barley had the power to do that. I just wants to die when you put any resistance on it like taking off from a stop. So i will try checking the boots when i get the carbs on. I hope its as simple as that. But at the same time those are pricey. Any more ideas will be great. I dont want to miss out on summer riding anymore

[Titbit21]

Also forgot to mention yes the 1 & 2 plus are white, and 3&4 are tan.

[JeffH]

First check that your getting fuel to the lean ones. Is a fuel line kinked? Is the petcock on? is the gas tank really low on fuel where one side might not be getting enough?

Now, if you know you have good fuel flow to both sides, and the problem persist, then check the mix screw settings. For a stock setup I tend to start at 2 turns out form lightly seated. After it gets running decent you can start tuning mixtures.

Sorry you are still having trouble getting your bike on the road. There has to be something obvious here that is just playing with you.

OK, you are satisfied you installed the right parts into the carb. Let's go back to what DGXSER said on April 18 regarding fuel flow. Your bike is stock, so Petcocks are Stock and have been rebuilt?? Since you say #1 and #2 run HOT then I'd ask: Is the Petcock working properly?? Is the Vacuum line attached and working properly?? How do you have your Fuel Lines Routed?? Are you using a Fuel Filter?? Have you drained the bowl to see how much gas comes out?? Say drain #1 and #4 into a shallow jar or pan and see if the amount is identical. Might be dumb idea, but sounds like fuel is an issue if Carbs and Adjust screws have all been checked and re-checked.

Assuming Carb Rebuilds AOK with commonly used George Fix jets and needles then let's start at the beginning and map the flows. #1-petrol is in tank #2-petcock opens up and releases fuel down the line into the bowl. Since you say #3 and #4 appear to run OK, then I'd verify the Fuel thing that DGXSER mentioned. It has got to be something really simple that keeps the bike from Idling and Running properly. Got a picture of your fuel line routing into the carbs so we can see it?

Let us know,
Jeff

[petejw]

have u synced the carbs yet?
u havent accidently broken the tips of
the mixture screws?
have u set the float levels correctly?
cpl of things to consider.

[Titbit21]

OK, you are satisfied you installed the right parts into the carb. Let's go back to what DGXSER said on April 18 regarding fuel flow. Your bike is stock, so Petcocks are Stock and have been rebuilt?? Since you say #1 and #2 run HOT then I'd ask: Is the Petcock working properly?? Is the Vacuum line attached and working properly?? How do you have your Fuel Lines Routed?? Are you using a Fuel Filter?? Have you drained the bowl to see how much gas comes out?? Say drain #1 and #4 into a shallow jar or pan and see if the amount is identical. Might be dumb idea, but sounds like fuel is an issue if Carbs and Adjust screws have all been checked and re-checked.

Assuming Carb Rebuilds AOK with commonly used George Fix jets and needles then let's start at the beginning and map the flows. #1-petrol is in tank #2-petcock opens up and releases fuel down the line into the bowl. Since you say #3 and #4 appear to run OK, then I'd verify the Fuel thing that DGXSER mentioned. It has got to be something really simple that keeps the bike from Idling and Running properly. Got a picture of your fuel line routing into the carbs so we can see it?

The petcocks were a issue last year. Over winter i ordered a rebuild its for them to stop the leaks i was having. When i went to do it i noticed the petcocks I had were not original, so the rebuild kits were no good. So i got on ebay, over payed for some petcocks and used my rebuild kits on them. One thing I didn't do was use the diaphram that was provided in the kits. They are K&L's and I read somewhere that the diaphrams they provide were a mm off. So i used one that was good in the new petcock, and the other I took from the old petcocks I had from last year. I think this might be my issue. Thanks for mentioning that. Does anybody have a good diaphram they want to sell? Or can I use the ones provided by the K&L's?

The way the fuel lines run are from the right side of the tank to the left carbs ( vice versa ) I have a inline filters so it was the only way I could route them. I really think the right petcock could be the problem if that is a common symptom with wrong diaphrams. I'll try and put a pic up when i get the carbs put back together and on the bike. If anybody has any knowledge on the K&L diaphrams please let me know. Or if there is a good right petcock for sale I am also interested in that.

[Titbit21]

have u synced the carbs yet?
u havent accidently broken the tips of
the mixture screws?
have u set the float levels correctly?
cpl of things to consider.

Carbs are benched synched right now. I have a synch tool but when i used that thinking it could be the problem, the closer tuned together I got them the worse it ran. Mixture screws are fine. I had that problem last year. Floats were set correctly to my knowledge at the time. I have to do all this again because they are in pieces, but I dont think that is the issue.

[Titbit21]

Also does anyone know what the measurement of the piston on the petcock diaphrams are suppose to be? I'm going to rip into mine again and check the measurements of the ones I am using.