[Admin edit: thread was (accidentally?) closed for no apparent reason, now merged with new posts. Carry on ]
How strange, I do admit I was quite confused. Thanks for sorting that out!
Please explain how EFI will eliminate the ignition system and/or how a more complex electronic controls system will be less problematic or easier to diagnose/adjust/maintain.......???
Most (all?) aftermarket EFI systems include ignition control (megasquirt, microsquirt, various arduino projects, all standalone EMS's). An EFI system is dead simple compared to a CV carb and 1980's CDI...the whole system contains around 3 moving parts, and a simple microcontroller with some I/O circuitry to run it. There's really nothing at all to go wrong over time, or go wrong at all really...and when something does go wrong, the system will generally tell you what it is or at least indicate which system has a fault. A closed loop fuel map is very easy to tune, and one would simply mimic the OEM advance "map" for ignition (for starters, anyways). Really I don't see how it
wouldn't be easier to diagnose/adjust/maintain than 40 year old carbs and mystery CDI's, especially since my experience with every old carb has been terrible, while my FI engines run perfectly all the time, regardless of weather or age.
After all, what's easier: hooking up a laptop and changing a few table cells, or spending an hour pulling the carbs to change jets, needles or set float height?
Thinking out load after reading this, and most of your original post…
Pilot/mixture screws are good?
Are you getting fuel?
Certain there’s no vacuum leak?
Certain the air cut & accel pump diaphragms are good - cracks in mine were very hard to see.
All carb gaskets are in place and seated?
Air filter is clean?
You said all ignition tests were good.
Don’t remember what you said about your compression test?
I don’t have an extra set of carbs to swap, sorry.
There’s no FI system I know of unless you build your own.
There are strobe apps which pulse the flashlight on your phone you may be able to use to check your timing?
I feel for you, there is a magic answer, you/we just haven’t found it yet. Stay on, you’ll get it.
Tom - 1982 CM450E
Thanks for the reply! I'll try to go line by line:
Pilot screws are new, along with o-rings, etc
I'm 95% sure there are no vacuum leaks, and least none I can detect with starting fluid or a little gasoline. The ONLY exception here is the throttle shaft, I do get some idle increase when I spray fluid at it...but that goes for both sides, not just the problem side.
Air cut and accel diaphragms are brand new, though I did just swap to the old air cuts with no change.
All carb gaskets (all one of them) are new and in place.
Air filter is brand new.
Compression does test low on my gauge, but I have no idea how accurate it is and both cylinders are exactly the same reading. Piston rings are brand new, cylinder was honed with a ball hone.
The app idea is interesting, might have to try one of them. Not sure how they sync up with the spark though, interesting...
I keep hoping for an aha! moment, where I find I made a dumb mistake or missed something, or something is obviously damaged somehow....but so far it is not forthcoming
I'm also looking into other, non-CV pumper carbs that I can potentially find new...something like a Keihin FCR or a Mikuni flat-slide pumper (I believe it's called a TM33?). I'm positive there must be another carb out there that works, just a question of figuring out what it came on. I know that a non-CV carb will not perform as well, but right now I'll settle for running at all!
Also, if anyone fancies themselves a carb rebuilding guru, I'd be happy to send the carbs out and pay someone to get them working! I'm happy to admit defeat here and break out the wallet, I only ask that you tell me what the issue is so I don't lay awake in bed wondering...