Kadron Carb Idle (Pilot) Jet Size - what are you running?

I know this is an old post, but I am running the same jetting, and also considering reducing my idle jet.  Mine seems a bit rich looking at the plugs and tailpipe.   Just wondering if you dropped to 50 idles, and/or made any changes to mains, and what the results were?

It's not unusual to have to mess with carb jetting to get an engine running optimally, even when someone else with a similar engine is running the same jets. Since you think it's rich, do 1 thing at a time, starting with the idle circuit- drop 1 size- and evaluate. DO NOT TOUCH THE MAINS UNTIL YOU'VE GOT THE IDLE CIRCUIT SORTED! 

Wow, that IS an old post, but "I'm not dead yet".  I did change out both my idle and main jets back in 2016.  Did idles first, no change, then did mains with complete carb re-build at the same time and that did not solve my running RICH"$$$$$" problem.  My engine runs fine cold, seems not so good when warm and I have a flat spot on acceleration at about 2000RPM that I don't think is related to carb jetting.  I'll have to dig through my parts boxes today to see what jet sizes I have in right now.  I think I went down one size on each.  I'll get back to you when I see what's left.  I bought two smaller sizes, still have the ones I did not use.

craig "Drive carefully My Friend"

PS, thanks for the reminder ALB.  You are correct as always.

craig posted:

Wow, that IS an old post, but "I'm not dead yet".  I did change out both my idle and main jets back in 2016.  Did idles first, no change, then did mains with complete carb re-build at the same time and that did not solve my running RICH"$$$$$" problem.  My engine runs fine cold, seems not so good when warm and I have a flat spot on acceleration at about 2000RPM that I don't think is related to carb jetting.  I'll have to dig through my parts boxes today to see what jet sizes I have in right now.  I think I went down one size on each.  I'll get back to you when I see what's left.  I bought two smaller sizes, still have the ones I did not use.

craig "Drive carefully My Friend"

5 bucks says your needle and seat are leaking. These are notorious for being junk in Kadrons.

You'll run pig-rich no matter what if that's the case.

If I were trying to get this right, I'd get a set of Dellortos, or try a set of the EMPI "D" Dellorto Copies. Under 2l, I'd get 36s; up to 2110, 40s; 2276 or 2332, 45s.

Stan brings up a very good point; if smaller jets don't make any difference, remember that the fuel has to be coming from somewhere. Leaking needle/seat assemblies are the next place to look, and it's not unusual for them to fail. Even fresh out of the rebuild kit they can leak- quality control being what it is these days (it's what we get for being the cheap assed people we've become, basing everything on price and not performance). Al

@craig- I'm not always right- just ask my better half!

My car runs great.  No miss, no hesitation. no smoke like other kadron owners have noticed.  No leaky accelerator pumps, honestly I think my carbs are in good shape.  I do have an SVDA with electronic ignition, properly timed.  New plug wires, new plugs.  I do not think the needle and seats are leaking.  But the plugs are always black when I pull or replace them, so I was just wondering what the experience was like with the 50 idles.  I have also read that with the SVDA you can run it a bit leaner, so I just looking for someone who had experience with the smaller jets.  I have a set of 50 idles right in front of me as I type this, so I may swap them out anyway and see what I get.  But if Craig came back and said it ran like garbage, I would probably skip it and find another way to waste the day.

I will sit back and await the numerous responses saying "if it ain't broke don't fix it."

If you have the smaller idles, put them in and see what happens (don't forget to re-adjust the carbs afterwards).

Seag8r posted:

My car runs great.  No miss, no hesitation. no smoke like other kadron owners have noticed.  No leaky accelerator pumps, honestly I think my carbs are in good shape.  I do have an SVDA with electronic ignition, properly timed.  New plug wires, new plugs.  I do not think the needle and seats are leaking.  But the plugs are always black when I pull or replace them, so I was just wondering what the experience was like with the 50 idles.  I have also read that with the SVDA you can run it a bit leaner, so I just looking for someone who had experience with the smaller jets.  I have a set of 50 idles right in front of me as I type this, so I may swap them out anyway and see what I get.  But if Craig came back and said it ran like garbage, I would probably skip it and find another way to waste the day.

I will sit back and await the numerous responses saying "if it ain't broke don't fix it."

 

Your motor may like them or not regardless of Craig's experience. No to motors are the same, even if built to be.

I put them in and started out on a drive to warm it up so I could get her up to temp and adjust everything, and it started raining.  So fine tuning will have to wait. 

However, in my short lived test run (3 miles) it idled decently and accelerated crisply with no lean pops.  The only thing I noticed was a tiny bit of a backfire on deceleration, which I am sure will improve with proper idle mixture adjustment.  So I am going to stick with them at least for the next week or two and see what happens with my plugs and running temp.

OK, my system has failed me.  I labeled the spare NEW jets and put them with the OLD jets I took out and now I cannot find them.  Which sucks because I was going to try the other new jets of smaller size to see if it would help.  I'm not done looking though.  I will start again in the morning after coffee and see if they show up.  If I go back through other threads on this note I may find the one I wrote about what size jets I had in when this started.  Will let you know.

Found this info on old thread:

I had 55's in for my idle jets.  Couldn't figure out why my car didn't run worth a crap.  I bought two sets of idle jets, 51's and 53's.  I put in the 51's knowing this was not correct for sea level, but I seldom believe what I hear.  Might have been right.  Car ran better but not good.  So I put in the 53's and have been running that way for over a month.  Runs OK.  Not perfect.

Glad I read this cause I was ready to put in the 51's.  I didn't remember that I had done that.  Sucks getting old.  My main jets are 130's.  I'm going to take the advice of Stan Galat and check out new Dels.  This is what I bought my Speedster for, cause I no longer have a boat to waste money on....

I have a boat also, so I am sticking with the Kads.   Looking toward to some dry weather to get warmed up and see how it runs, and what my plugs look like after a few miles with the 50s.

Craig---if you need it, I can loan you my carb jet gauges.  I'm pretty well dialed in now and they were pretty handy a few years back. Lemme know.

Jack, Tell me more.  What do I do with them?

K-dogs can be easy or a pain in the a....  you may go lower on the idle circuit.  But let's go back to the basics. Both carbs opening at the same time?

accelerator pump adjusted properly. Are you getting a good stream or is it dribbling out of the discharge tube. Adjust it so the is a good stream. 

Start with the idle mixture at 1-1/4 turns out.

start it up and let it warm up. If you a large flat stop the first thing I do is add a turn inward. 

If still having a flat spot or rough transition go another turn on the idle mixture screw

Make sure your distributor advance is working properly and timing set correctly

also be sure fuel pressure is at 1.5 psi

good luck

They are gauges that you stick into the opening of the jets to see what size they really are.   You can Google Carb jet gauges.  Sometimes jets have been reamed out to a larger size but still are marked with the original size.   Over the years I have seen some large variances from what the jets were marked.  Weird--right?   

Craig I don't know if your carb issue is jet size but if you want to know for certain what your jet sizes are,you are welcome to borrow these gauges.