Confused

And don't forget to bench synch the carbs, as this gets them closer for final synching and pilot mixture adjustments after installation.

Gah.... So I cleaned up the second one, and decided to throw the carbs back on just to see what happens. Second cylinder firing, couldn't be any more excited. I sprayed the other exhaust pipes just to be sure, and now the 4th isn't firing... Got em off and I'm cleaning them all now. Any idea how that could have happened...? Weird.
-Ed

Is a fresh in-line fuel filter being used?

Check the garage for gremlins... Saw one run off with my 10mm socket.. :whistle:

Patton wrote:

CptEDIV wrote:

Yeah, Vacuum from petcock goes to the second carb. I got em capped off, then I tried running it and checking the plug... It was dry and brand new lookin still. So I found another post about a similar problem, where someone had just moved the carb over to the left so that the 3rd carb goes to the second cylinder. I tried that, and ran it, sprayed the exhaust and sure enough, it was firing. So that means it would have to be the second carb? I got the carbs off and am working on cleaning 'em now. Should I have it put all the way together and ride able before trying pods and new jets? I have a real hard time with my airbox and air ducts... I was hoping clean them, rejet then put it all together with the pods to avoid having to take the carbs off and apart again, not to mention my airbox looks and functions like crap. What do you think? Thanks a ton, this site has been incredibly helpful. -Ed

Thanks for the report indicating problem in #2 carb.
If reasonably sure about best jet sizes for pods and 4/1 exhaust, grin and go for it! :woohoo:


Special attention to #2 carb --

Assure float-needle-seat is not clogged and preventing fuel from entering float bowl.

On my Mikuni BS38, the main jet is at the very bottom and feeds all the other carb systems, including the pilot. I wonder if your main jet system is just blocked with crud somewhere.

CptEDIV wrote:

Gah.... So I cleaned up the second one, and decided to throw the carbs back on just to see what happens. Second cylinder firing, couldn't be any more excited. I sprayed the other exhaust pipes just to be sure, and now the 4th isn't firing... Got em off and I'm cleaning them all now. Any idea how that could have happened...? Weird.
-Ed

maybe floats sticky and binding in the UP position and cutting off gas?

What causes floats to stick? They seemed free when I had the carbs off. I put the carbs on after a pretty thorough cleaning and it actually had all four firing. Then I started to put everything back together, but decided to try it again, and Im having the same problem with the second cylinder again. I tried tapping on it and running it wide open then putting my hand over the air side of the carb to see if it would suck gas through, and half the time it'll fire on the second cylinder when I do that. I'm stumped, I'm taking them off again and pulling up a diagram and going through the second carb again...

Try to make sure floats are not hitting/rubbing on anything such as the inside of the bowl. Are you using new needle and seats or old ones?

Patton wrote:

Is a fresh in-line fuel filter being used?

Hello? ... Hello? ... [tap] [tap] [tap] ... Is this thing on?

Just kidding! :laugh:

Many a perfect carb cleaning job has been instantly screwed by an onslaught of new crud. :ohmy:

Keep the Faith!

Haha... Sorry. Yeah I gotta fresh fuel filter on it now.. I didn't before though. Using the old needle and seats. I've found that I can get the second cylinder to fire by revving it up, then putting my hand over the intake for a second and letting it go at a high RPM. But even after I do that just idling and revving it won't get it to fire. Actually the last time I cleaned it the second cylinder did fire the first couple times I tested it, so it seems like maybe more crap just got into the carb again, but I'm not sure. Thanks for the advice.
Ed

Curious: The second time I cleaned the carbs, I took apart the accelerator pump and found some brown mushy sedamenty looking stuff. I didn't find much of it anywhere else in the carbs, mostly just the pump. Could the accelerator pump circuit being blocked up cause the second cylinder to not fire...? The second cylinder is the one with the accelerator pump.
Thanks,
Ed

CptEDIV wrote:

Curious: The second time I cleaned the carbs, I took apart the accelerator pump and found some brown mushy sedamenty looking stuff. I didn't find much of it anywhere else in the carbs, mostly just the pump. Could the accelerator pump circuit being blocked up cause the second cylinder to not fire...? The second cylinder is the one with the accelerator pump.
Thanks,
Ed

That brown mushy stuff is rust coming from the fuel tank.
Do you have good inline fuel filters?

I suppose it could be blocking the flow into that carb's pilot sytem if that's where it feeds from.