Carb rebuild

I have a 97 Heritage Softail Classic. Did anyone rebuild their Keihnin carb lately. Most rebuild kits seem to come with two float bowl gaskets. Is one extra for a different year or type? Are the other provided parts necessary or should I just change out the float bowl housing O ring? My bike burps and backfires once in awhile. My guess is that the O ring should be replaced but I'd like to do a thorough job if it is necessary. I changed out the Manifold seals on the intake and where the carb connects and rejetted. I sealed the muffler and pipes. The carb seems to flood when it's started, shut off, and then restarted again when she's not totally warmed up.

That's exactly the case. If I started the bike and then pulled into the garage and shut her down. If I start her she will backfire. I have the same thing on short trips and sometimes longer trips. Any thoughts on how to stop it?

Re: Carb rebuild - Float Setting

After replacing a leaking slide diaphragm, I'm in the process of fine tuning my carb. Having experienced some weird problems with mixture screw response I've determined that the float level is off - too high. I understand that this will effect everything else, and must really be addressed before any other changes. Fortunately I've got the entire process of removing the carb and replacing a needle or jet and re-installing down to under 5 minutes now as I've done it so many times.

My dilemma is the float adjustment. I've read through the shop manual part on this several times. Does anybody know exactly what we are attempting to accomplish with the 'tilt 15-20 degrees, adjust space between flange and bottom of float to 0.413 - 0.453 ? Sure would have been nice if they included something a bit more technical - like the target fuel height in the bowl. Does anybody have this number, or is it classified. Is it 'at the same level as the flange, 1 or 2 mm below the flange, or what?

I know I'm set too high as when I very carefully hold the carb upright, remove the 4 bowl screws, and carefully drop the bowl straight down, I always spill gas - indicating the fuel level is ABOVE the O-ring flange seal.

Is there an alternative procedure than that in the HD manual for adjust this? I've seen where people use clear tubing attached to the drain and curled around facing up to view the level, but this is a later carb with no drain. This also requires knowledge of the target fuel level which it seems Harley doesn't think is important to provide. I would think the target fuel level would be constant for all CV40 carbs regardless of what bike they are on.

Performance is fine, no missing, backfires, or roughness, but it seems to be running rich - carbon in the exhaust and heads by the pipes, and fuel economy is poor. I expect I inadvertently 'adjusted' it when I was cleaning and replacing jets.

I want to get the float adjustment right on before spending any more time on tuning the jets and mixture.

There's gotta be a few other hold-outs out there who are still running carbs and have figured out what Harley's float level 'instructions' are trying to accomplish...

Waiting to hear from Ken - I know he's a busy guy. In the meantime I braved the cold yesterday and pulled the carb again and adjusted the float level (lowered it). I still say the HD procedure in the manual is terrible. Took a 50 mile test run (brrrr) and this definitely had an effect. It took a long time to warm up, and sputtered some even after warmed up (it hasn't sputtered since I owned it). Full throttle performance was fine and no hesitation so I'm assuming the float level is not too low. Sluggish just off idle, and didn't return to idle immediately after stopping - hunted a bit. Quick / not too accurate MPG check 43 mpg - last check was 35 - I have gotten as high as 48 in the past. I'm convinced I bumped the float and accidentally 'adjusted' the float level when I replaced the slide diaphragm. Replaced the 44 slow jet with a 45 to fatten up a bit and re-adjusted idle - it's much happier with the 45. Will run a tank through today to see how she behaves. Presently 190 main, 45 slow, factory needle. Have a CV Performance needle to try once everything else is stable. Carbs are fun .

Might want to check for intake leaks too.

Haven't sprayed with anything, but the boot looks new. I did put a thin coat of vaseline on the carb boot to make it easier to slide the carb in and did the rear of the boot too. Good idea - should spray with WD40 to make sure.

Doesn't hurt to double check stuff...did you check the inlet valve too??...float could be at the right level but if the valve is worn it will let fuel seep past it...

Float was definitely too high. I did check the valve by blowing on the gas line lightly and it seemed to seal real well. Seems to me that blowing on the gas line might be a pretty good way to see exactly where the valve closes. That's how I verified the (for me somewhat obscure) HD procedure for setting the height. Float was exactly parallel to the sealing flange when it closed. Maybe I should write a new procedure? No funky angles, no vernier caliper needed...

As many times a I've had the carb off in the past week, and I've read about this plastic fitting, I never checked. Took a look after reading this and sure enough it has a brass fitting. Whoever drilled out the mixture plug originally must have done it. Thanks for the heads up.

It is kinda a pain setting the float level,I used my drill press and set the bed to 15-20 degree angle, I just made sure it was on a level surface...was alot easier then...I do recommend the V-Ductor...I put it on my bike and noticed a improvement right away...good luck..I won't be ridding til spring since we got snow on the ground and it has been in the single digits here...you might say dam cold!!!!!!

Tilting the carb to the 15-20 degrees gets the float to touch the float valve without compressing the spring loaded pin in the float valve. More than 20 degrees and the pin gets pushed in, less than 15 degrees and the float don't touch the pin. Either one and the level will be set wrong.
The carb on my 03 had a brass fitting from the factory.