I’m learning how to tune the carbs (via SOC, John Muir, YouTube, and some neighborly adult supervision from @Sacto Mitch).
This is the "before" video. I think I’m hearing a limp instead of a steady beat.
How does it sound to you?
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A limp would be a good description. Can hear it in the 750, and 2000.
Where do you think you hear the limp, Ryan? I think it sounds pretty smooth. Idle sounds good (for kadrons)- they'll make that little characteristic ba-bump, ba-bump rhythm, which is the 2 cylinders on 1 side firing sequentially and then the other 2 doing the same thing. This idle is typical of all dual 1 barrel carb sets- I've been told that if you take the manifolds and grind out the inner wall separating the 2 barrels (from the top) to about 1" above the head surface so each cylinder has the bigger plenum to draw from in succession the engine will idle as smooth as dual 2 barrels (which when adjusted and tuned correctly "purr").
2000 rpm- I think I can hear some light backfiring, but still very smooth.Check the linkage to make sure the carbs are synced together when the engine is thoroughly warmed up. If you're confident that the carbs are adjusted properly you could try a 1/2 step (eg- 50 to 52 1/2 instead of to 55- you may have to find someone with carb jet drills) richer idle jet to see if they smooth out more at 2,000 rpm.
Overall, they sound pretty good! Hope this helps. Al
Sounds pretty good, but just a tad off - which could be many things.
It could be the engine isn't warmed up all the way - was this just idling in the driveway without being driven?
It seems to be on the verge of popping a bit at 2000, but not at 3000, which could be slightly lean idle mixture.
Or it could be in the distributor. Mine had a slight 'miss' between idle and about 2200 that I couldn't get rid of with carb tuning. The timing also jumped around in that rev range, too.
A Magnaspark dizzy cured that for me, but your dizzy might be just fine. The best way to check is to put a timing light on it and watch what it does as you increase the revs.
With my old dizzy, the timing mark was all over the place until about 2500 rpm. With the new dizzy, it moves steadily from idle advance to full advance as the revs increase.
Sounds pretty good to me.
After. Thanks for all the help. As much as I studied the material, it was clear I needed an expert. Thanks to all that offered their expertise - @Sacto Mitch, @Rick99GSX, @kart45, @ALB, and @Todd M!
I took it to Bugformance to get some help. They replaced some exhaust gaskets and tuned the carbs to perfection. No more backfires and it drives very well.
Here’s a quick video of the result, at idle, 1k, 2k, 3k and 4K RPMs. What do you guys think? I didn't label the video, but I stuck around at each step for about 10s.
BTW, they also checked up on the welded fork arms and confirmed they are still in rock solid shape. It drives accordingly! Can't wait to put more miles on her.
It looks to me like the belt is a bit loose. I'll throw another shim or 4 into it and see if I can resurrect before replacing.
Nice!
Good for you, Ryan!
Idle is now at about 9500. It was 7500 as long as I can remember. Excited for more miles of smiles.
Good deal, Ryan! It now has that nice 'balanced' sound at idle and up through the rev range.
Getting the two sides in synch can be a struggle, but the difference is obvious once you're there.
Were you able to watch as they tuned it? Did they adjust the linkage at all?
I wish. I wasn't able to watch. I dropped it off and Ubered to work like the luddite I am.
I LOVE the new ride, though. I put this off for too long. I didn't realize how bad the power gaps were. I just picked the kids up from school (hi @Gary P!) and the boys commented about it as well.
It's going to be a great year of driving.
... For the past couple months I was lulled into the modern era with my big 2018 car with every luxury. Now I'm ready to go back in time again.
So glad to hear it all worked out and you're back in love with your ride! Sounds like time for...ROAD TRIP!!
Ryan in NorCal posted:Idle is now at about 9500. It was 7500 as long as I can remember. Excited for more miles of smiles.
9500 seems high for the idle. 
I thought only Pat D hit those numbers with his drag car!! As long as your tins are in place you should be good though.
Ryan in NorCal posted:I wish. I wasn't able to watch. I dropped it off and Ubered to work like the luddite I am.
I LOVE the new ride, though. I put this off for too long. I didn't realize how bad the power gaps were. I just picked the kids up from school (hi @Gary P!) and the boys commented about it as well.
It's an amazing experience to get it tuned RIGHT. I've done a few cars for people and they had no idea that their car could run that well.
Remember, ice-cold valve adjustment, plugs, points, timing, fuel pressure, float adjustment first. Then get the engine good and warm, like really warm, not just a few minutes. More like 20-30 minute hard run.
Then, and only then work on mixture, synch, and idle speed.
Cheers.
DannyP posted:Ryan in NorCal posted:I wish. I wasn't able to watch. I dropped it off and Ubered to work like the luddite I am.
I LOVE the new ride, though. I put this off for too long. I didn't realize how bad the power gaps were. I just picked the kids up from school (hi @Gary P!) and the boys commented about it as well.
It's an amazing experience to get it tuned RIGHT. I've done a few cars for people and they had no idea that their car could run that well.
Remember, ice-cold valve adjustment, plugs, points, timing, fuel pressure, float adjustment first. Then get the engine good and warm, like really warm, not just a few minutes. More like 20-30 minute hard run.
Then, and only then work on mixture, synch, and idle speed.
Cheers.
You coming through Charlotte anytime soon Danny?
Probably not. But if you bring her to Carlisle, I'll take a look.
