Weird Kadron issues

[rsb]

I have weird issues that are not covered in the kadron book, Kaddieshack's website, or lowbugget.

First off, the mixture screw is not doing it's thing. When you turn it in (leaner) the motor does not stutter or stall, it speeds up. How do I make it stop?

Second, It runs SO RICH. I can't tune it indoors. Whatever I am wearing while I tune goes straight in the washer. Yeah. That smell doesn't wash out.

Third. It is doing this really cool thing where if you rev it up, the throttle hangs up around 2,000 RPM and takes 20-30 seconds to drop down to idle. (nothing rubbing)

I tried tuning lean, exhaust is barely visible at idle and doesn't burn the eyes. That's about 1.75 turns out from fully seated on the mixture screw. Still have the hanging throttle thing, but it starts popping out of the carbs around 2,800 RPM.

Help?

A bit of backstory: I bought a motor off a guy I raced against a couple years back. Got a sweet deal as it is kind of a mystery motor. he bought it as part of a complete running car. Story is it's a 1776. It came with dual Kads and a 009 Dizzy, Petronix electronic points.

At my last race, the motor started running hot and loosing oil pressure. (loose fan belt, crankcase venting to cooling fan) I started with by adjusting the valves, checking the dwell, setting the timing. I got to adjusting the carburetors and the driver side unit would not adjust. Seeing as the sucked a lot of silt and things were rattling loose I bought a new set.

So new set of Brosso Solex Kads from Kaddieshack. I opted for the jets and venturi they recommend for a 1776 and installed them. Using my newly purchased jet gauge, I discovered that the main jets in my old carbs were a size bigger than the new ones. same idle jets, Old venturi were a size larger as well based on the stamp.

Linkage is EMPI with the solid center link between the 2 carbs with the shorter arm to the accelerator cable part. It's ferrous, magnets stick to it. I have it dialed in pretty good for synchronization.the set nut on the passenger side stripped out the threads on the link so I welded it in place. It's sitting on isolated runner steel intake manifolds. The port work is poo, but I spent 6 hours truing up the mounting flanges. Could have probably used 6-8 more hours, but each face has a level patch now. Intake gaskets are ferrous metal with crushabilty.

Oh yeah. I also installed a fuel pressure regulator (also from Kaddieshack) it's set to 1.5 pounds. Accelerator pumps deliver a squirt when the throttle is depressed, but otherwise aren't weeping.. New plugs.

[slayer61]

Never worked on kaddies, but if I was to guess.. it sounds like your idle jets are way too big. You're choking the fuel down when you screw the mixture screw in, and the engine is liking running leaner. I'd start there... someone who knows better will surely be along shortly!

[rsb]

It's possible the idle jets are too large for my circumstances. The previous carburetors that ran fine on this motor had the same size idle jets... but larger mains and venturis.

I called the company I bought the carbs from and got some advice. The guy I talked to thinks a vacuum leak is probable, but I haven't found it yet. He also suggested that I check out my distributor. I was only able to squeeze 26* out of it last I checked, so I swapped that out for another one I had on a different motor that does 30* advance. That seemed to smooth things out a bit.

Then it was back to fiddling with the carburetor adjustment. I started with the recommended starter setting of 2 turns out from fully closed. I discovered a sweet spot 1/4 to a 1/2 turn in from there where the engine slows down about 70 RPM. (keep going and the motor speeds up noticeably) So I am using that as the sweet spot.

RPMs still want to hang around 2,000 RPM when coming off throttle. Mid range is soggy as are hills with conservative throttle. And it has an intake backfire sometimes around 3,00 RPM if it has a chance to load up on fuel... but it accelerates! (and doesn't stink to bad)