Ok - having spent my entire Sunday (it's now 9:30 pm my time) fiddling with everything I can think of that might make a difference - I've made zero progress. Let me go back and address suggestions/ideas so far:
- Gas is fresh - less than a week old - purged the tank completely.
- Shot carb cleaner into each carb numerous times - engine runs beautifully for all of about 2-3 seconds then dies.
- Tried with carb box (air filter) on/off, etc - no difference. If I put my hand over 3 of the 4 carb mouths (hand's not big enough for all four), it will run until I pull my hand off. (P.S. - getting the air filter box back on properly is a real bitch - if anyone has some pointers on making it easier, I'm all ears)...
- Carbs are getting plenty of fresh fuel - I pulled the fuel line off where it attaches to the carbs and ran about a quart of fuel through it just to make sure (thanks Tracy) that no old gas from the line/filter were to blame.
- Exhaust is fine (thanks Timbone) - had just replaced the exchange box (took the box from my "parts" Cade for now until I can source a new one from Tracy) - front pipes, rear (down) pipes, exhaust pipes, exchange box - all fittings are tight, pipes are 100%.
- Intake manifolds were inspected when I rebuilt the carbs - all fine there too. Replaced the o-rings (as part of Tracy's rebuild kit), put in the new hex bolts, all good there.
- Main jets are fine (assume that's what you meant, Timbone?). Pilot jets are also in good shape - I replaced two of the four when I rebuilt the carbs - the remaining original two looked to be in good condition.
Other items:
- spark plugs are clean and set to .65mm
- pilot screws were set at 1 1/4 turns upon rebuild
- I have NOT performed a fuel-level inspection as per page 6-25 of the service manual - if you think I should, I'll figure out a way to do so.
Not sure what else to check at this point. Without any other flashes of brilliance, I'll probably remove the carbs again, check tolerances and re-fit.
If this were my first Cade carb rebuilt attempt, I might have given up by now (not really, I'm a persistent SOB), but this is my third Cade rebuild and the first two were a breeze - both fired up as soon as the newly rebuilt carbs were installed. Puzzled and bemused am I.
Are you trying to run it with the choke on?? Are the cables pulling the plungers fully?
Try it with the choke off. If it runs then you didn't do a good job of cleaning the enricher jets. They are integral to the carb body and must be cleaned with a really small wire if plugged (like an individual wire off some throttle cable.
I've tried with choke on full, totally off and every conceivable position in between. Cables seem to be pulling fully on both sides.
I used a wire in every tiny orifice throughout the cleaning process, but who know - perhaps something got clogged somehow?
After I clean them with a wire I also blow brake cleaner through them to make sure it shoots out where it's suppose to.
I am no expert on the cades but it sure sounds to me like your air fuel mixture is off. This is a classic sighn of to much air. Is there a chance that some where in the assembly process of the intake or carb base that it is drawing a vacume leak??? That would be my logical next step. And I say this because you said all is fine untill you remove your hand and the choke is functioning properly.
