72 CL450K5 Scrambler Keihin 14H Carbs Running Rich

[cafescrambler]

I was hoping you all might be able to provide some insight into an issue I am having with my Keihin 14H carbs. I've followed just about every set of instructions out there on how to tune these CV carbs and cannot get them to run lean enough so that fuel isn't slowly dripping out of my left exhaust gasket along with white smoke and moisture coming out of my crankcase breather tube at idle. My plugs are black too, so everything points towards too rich of a fuel/air mixture.

Everything with the carbs are stock except for the Uni sock/foam filters (which have been oiled). I have the original air filters (and plastic covers) but they seem pretty dirty and the paper feels hard/dense, so I don't think they would cleanup well following the instructions in the owner's manual (says to clean them with compressed air.) I've cleaned both carbs and have replaced the gaskets and o-rings. I've measured float height to 20mm. I've also verified that I don't have any air leaks.

I don't have any problems starting the bike. And it stays running and idles nicely around 1200-1300 rpm. It just starts dripping fuel from the aforementioned places within a few minutes.

Everything I've been reading online seems to be with people having issues resulting from aftermarket air filters. It sounds like they're getting too much air and not enough fuel. And run into issues with their bikes stalling or not starting at all. What's interesting about this is that I'm having the exact opposite problem.

I'm also wondering if anyone knows the order of the rubber o-ring, washer, and spring that go on the air mix screw on these Keihin's? I've seen conflicting diagrams and photos between the Honda Service Manual, Clymer Repair Manual, and other online resources.

I appreciate any feedback you all might be able to provide. I just got the bike running (after who knows how long it has been sitting), titled, and registered. I'm itching to ride now that warmer temps are here, but am also worried about ruining my engine given how rich this baby is running.

 

[cxman]

oring first then washer then spring make sure the oring goes into place or you can break the tip off the jet when seating it

i would consider ordering new stock jets from say jetsrus.com i have rebuilt so many of these over the years and some pin

head has drilled out the jets or otherwise opened them up then the numbers read right but they are junk

and can fool you

new jets are cheap and they will give you a base line

clean the stock filters as best you can and get the bike working with then then change to the unis after

one of the ones i have lol i love cls

 

[cafescrambler]

Thanks for the info!

So, from screw head to tip it should be o-ring, washer, spring like image (a) below..

image (a)

and NOT like #6 in the parts fiche in image (b)

image (b)

I also looked into finding replacement jets on JetsRUs.com, to no avail (only had them for CB/CLs 68-71)... But will keep looking.

I gave the stock air filters a good cleaning. Am going to give them a shot. I'm also rechecking valve clearance, cam chain tension, and contact point gaps to make sure that I have everything dialed in with timing.

Thanks again!

 

[cafescrambler]

I also wanted to post some feedback that I received from the fine folks at Dime City Cycles...

Wow, that is a hard one to diagnose, too many scenario’s to advise without having the bike here. I've found there really is no equation for jetting, there's just too many variables ( filtration, exhaust, elevation, timing, valves, etc,) at the end of the day it really just comes down to trial and error for me.

After you've done all your mods, start the bike up with either the stock jets. If drastic jetting is needed you can generally tell right away as she idles and you snap and rev the throttle. Your low, mid and high bands may cough, sputter or become non-existent. If that's the case go up or down as needed with the main jets, but NOT before you try to adjust your air/fuel mixture. Once she's idling and revving at a good constant, I then usually run the bike for about 2-3 miles and read the plugs and decide what she needs from there and just go up or down and start making jetting changes until the plugs have a light chocolate color to them. Ride the bike after every change for at least a mile or so. Don't forget to adjusting the air/fuel mixture after every change.

Although before all of that, be absolutely sure your timing is dead nuts and the carbs are all well sync'd, otherwise you'll forever be chasing your tail and you'll never get her running right.

Hope that helps a little and please read link below.. Good luck!

http://www.dimecitycycles.com/dccfaqs#jetting_basics

 

[cqyqte]

Take the filters off completely and run it for a few minutes and see if you are still rich. Unifoam filters and oil will restrict air flow more than the stock filter if there is too much oil on them. If you run leaner without the filter thats one issue, I agree with the o-ring on the pilot/air screw. Also check your floats the correct way, remove the carbs from the bike, remove the float bowls, with floats hanging down rotate the carb body so that the floats start to fall closed by gravity. Immediately when the float stops closing stop rotating the carb body and use your measuring device, I use the precut credit card template, to measure the distance from the bottom surface of the float to the machined surface of the carb body where the float gasket contacts. The point where the floats stop moving is the point where the float tab makes contact with the float valve and has not yet caused the internal spring to compress.

Floats set too high will cause a rich condition as too much fuel is being allowed to be pulled up the mainjet and pilot circuits. Good luck, we've all been there