Rocketraider, do you happen to have a link to that discussion? It sounds interesting to me for sure. I'd like to have a read.

I know you don't talk to me, so a link would be more than generous.

 

It was a while back so might take a bit to find it.

He's been a top carburetor guy for 60+ years though he's stopped actively repairing them. Still makes kits and is generous with his talent and knowledge.

 

Here's one. As you see our own Joe P is there too, as is Pat McMillan deaddds.

https://forums.aaca.org/topic/388429...omment-2458400

 

Cool, I'll give it a try.

 

Trying a little different approach first. Not done cleaning it up yet. By taking away some of that flange (I'll remove some more), the threads can reach the still-good threads in the carb. Also I can use a slightly squishier gasket. Don't ask me about my "lathe". I picked up at least 3 more full turns into good threads so far.

 

Great info, thanks! This is a good read and I learned a few things that I never heard about before. This balloon thing for the QJet inlet sounds like hot garbage.

 

Done. It threads in nicely. Carb parts are in the ultrasonic washer. Will give it a try later.

EDIT: Did not work. Leaked.

 

Gang,
I’m seeing some highly modified parts.

Helicoil could work and if you use it, I hope it does. But remember the carb sits on the intake and all those metal parts spend their lives expanding & contracting with engine heat.

Thick gaskets will probably help short run, but how will you know when they don’t work anymore? Your signal will be either a gas leak you might smell (if you’re lucky…) or a gas drip onto a hot intake manifold at speed or a carb fire.

I’m no stickler for originality, so, genuinely, pardon me — are you really _that_ committed to using a ‘66 carb body with stripped fuel inlet threads?

I had that fuel leak in a rebuilt ‘66 carb which turned into a carb fire 35 years ago. I’m in the “never again” category on the question of kludging a fuel inlet. I mean, hell, _gasoline_ flows through it - designed to ignite. I’d replace that carb body without a second thought.

Feel free to ignore me, but I’d put the stripped carb on a shelf and use something safer even if it’s not the correct number.

I highly recommend a later 170-series (75 & up) emissions carb for greater CFM, better inlet design and greater tune ability.

Hope I’m not offending anyone here. I just carry a healthy fear of early qjet fuel inlets from my younger days.

Chris

 

Yeah, I'm in the camp of "not worth it" as well, except all is not lost with that Qjet. The repairs done with the helicoil are a solid repair that is definitely a permanent fix......especially with a later generation carb like you have there. My 66' Toro also had an engine fire a few years back that started somewhere around the carb. We're not 100% sure how it happened but the carb leaked while my dad was driving it and it lit up. He had quite the engine fire going when he popped the hood. He pulled into a parking lot and just barely managed to put the fire out with an extinguisher. He reckons another 10 seconds and the car would have been lost. We got very lucky. He suspects it was a loose inlet fitting, but there's no way to know now exactly what happened. I've spent the last year replacing wires, connectors, and various burnt components as a result of that fire.

That fitting that your using on the inlet has a couple things going on. Stripped threads as well as an adapter to a rubber fuel supply hose on the pressure side of the pump. You're obviously a very capable mechanic so get that helicoil installed and make up a nice hard line from your pump to the carb. Replacement inlet fittings are also easy to find. I bent up a replacement hard fuel line and put the flares on it.......worked a treat, looks great, and also gives you peace of mind. That carb fire is always in the back of my mind whenever I'm driving mine.

 

Yeah I know it's pretty half-asssed, but the threads now reach the good threads in the carb body, and I was able to use a normal gasket. If I can not tighten it to original correct spec I'll deem it a failed attempt at 'creativity'. The only sealing surfaces are the underside of this fitting, and the carb body. Both are flat now. Why did they only give this thing 5 threads when there are 18 in the carb? As for the hard line, I guess I've had so many carbs with rubber fuel injection line going to them, that I don't even think about it.

 

Idle mix adjustment screws

Shouldn't these have a dramatic effect on idle mix (to the point of getting it to stall) over their range? Mine don't seem to do anything, although the idle is currently good. Everything is cleaned out been through the sonic washer and a whole can of carb cleaner. I've adjusted a *lot* of carbs idle, and this one just doesn't react like what I'm used to.

 

Definitely not my area of expertise. I would suggest starting a new thread about idle mixture screws. There are folks on here who are awesome with these things. In my brief time working on these things it seems like a bunch of things can cause ineffective idle screws.

 

Ah I just figured it out... It wasn't technically idling. Needed a little more timing to allow closing the butterflies to run the idle circuit.

You all will be relieved to hear that the fitting leaks a tiny bit. (I was able to do tuning). So, I'll be fixing it the right way.

Really runs amazing now, including cold startup!

 

Congrats on figuring it out. It’s a common problem with qjets that the throttle blades are just above the transfer slot and allow just enough gas in to overwhelm the idle function.

Cold start going right is a great sign you’re on track. Chokes can be tricky.

Chris

 

Nice! So what is your base timing at currently? I think the spec is 7 degrees btdc correct?

 

I'm at 14 now, assuming the pulley hasn't moved. Will pay attention on next test drive.