At my wits end! Still running lean

One more question. My VM26's have 1.5 slides and the VM28's have 2.0 slides. Would putting the 1.5 slides in my VM28's help? Is swapping slides between carbs even a good idea?

The O-6 is 2.63MM and the O-4 is 2.62mm

Larry if you are talking about 17.5 pilot jets, I have those. Wouldn't that make it even leaner since I'm running 20 pilots now?

otakar wrote:

The O-6 is 2.63MM and the O-4 is 2.62mm

Otakar,

Wow that's a small difference! So, do you think that having one 0-4 mixed in with 0-6 jets would be ok? I know that I got away with it before, but I never had a chance to ride it with all the same size jets.

I guess that big question is what is in my VM28's now. If they are 0-1's then I could where changing them would help. If they are 0-4 I can't see how it would make much difference.

Jeez, I thought rebuilding the motor would be the tough part of this build! It was a piece of cake compared to pulling the carbs for the millionth time! LOL

An O-1 is 2.605mm. The difference between O-4 and O-6 is .04mm/2 that is actually quite a size difference when it comes to flow. That is a 5% difference in area of flow.

fordtruck wrote:

Larry if you are talking about 17.5 pilot jets, I have those. Wouldn't that make it even leaner since I'm running 20 pilots now?

Hmmmm....those carbs should have the long pilots. I've never seen a #20 long pilot. But yes, that would be richer. Generally they had #15 pilots.

I don't know if the slides will swap. Maybe, you'd just have to see if they fit from 26 - 28. The must fit correctly..can't have them sucking air around the sides. Kaw always ran 1.5 slides up until that year. That would richen things up in that area where you're surging....

Otto...have you ever tried that swap from 26 - 28?

Never did, but I believe that the 26s were able to be bored out to 29s so the slides might be the same. I believe they were both 30mm slides. But the slides were not all the same they had different cutaways.

I looked today but I don't have any D taper needles or OEM style needle jets.

Your idle & cruise jetting is already richer than what I would expect. Best to check the fuel levels. I'd do that before I swapped the slides out.

Let us know how you make out

I think that the biggest mistake being done here is that way too many variables are being changed at the same time.

How do you figure?

He only changed the needles and it helped a bunch. BUT the clip position he requires is much richer than I've ever seen one need.

Since he has no leaking manifolds, that leads me to believe the fuel levels might be low. That's the first place to investigate when the jetting is out of the normal range for needle operation...

His needles with O-4 needle jet should work fine.

The #20 pilots are a bit odd in those carbs....another thing that would lead me to check fuel level...

Slides would be the last thing I'd swap. It shouldn't need them but for a fine tuning effort....it's cool.

Larry,

I will check the fuel levels again. I checked it with the clear tube method before I ever put the carbs on and they were all about 1/8" below the carb body. Maybe something changed one of the many times that I've had them apart!

I've also done the ride test in first gear. I could feel absolutely no surging in first gear. It only happens in higher gears on the highway. I figured that it was caused by the wind on the air pods.

Otakar, please explain. I was only talking about changing the slides and needle jets. The only thing that I changed yesterday was the needles. I really value everyone's opinion on here. I know I sure have learned alot about my bike in the last couple of years just by reading this forum.

I checked the fuel levels this morning using the clear tube method. My manual says the level should be 4mm below the carb body. Three of the carbs were ok, but one was 6mm below the body. I corrected it. Is 2mm too low enough to cause problem? I didn't have time for a test ride.