Greetings everyone,
I'm trying to get my carbs tuned just right on my '77 550F, 069A carbs. Rebuild was done on them about 50 miles ago. All the jets are stock, 38 pilots(idle) and 98 mains. I have yet to sync them with any type of guage, but it is pretty close as I can get it to idle pretty well at about 14-1600 RPM. Making things more difficult, the temperature here in Texas dropped today and it's probably going to stay that way for a while. Floats were set at around 22mm.
I recently adjusted the valves and cam chain slack, checked the points' gap, timing (dynamic and static), changed the oil, recent plugs w/ correct gap.
I'm running a Uni filter, oiled well, and the stock 4-1 albeit with the baffle removed. The header gaskets are new. Carb boots are verified tight. Also, when I had the carbs off to rebuild I smoothed out the intake runners a bit, careful to remove a minimum of material (new gaskets on these).
What exactly is the correct number of turns out on the Idle Mixture Screws for these? I thought it was 1 or 1 1/8. I initially set it at this, but there was a little of popping out the exhaust at idle. After adjusting to about 3 the popping has went away from the rev range. This tells me turning these screws out enrichens the mixture correct? When I did my initial IMS setting it was about 80-85F.
Until today, currently about 55 degrees F outside. In first gear there seems to be a bit more hesitation/bogging right off idle under load low in the RPM range. Note: before adjusting my timing (which was WAY advanced), this bog right off idle wasn't there. And I'm not sure, but I think it may be popping a bit when rolling off the throttle quickly at speed. Kinda hard to tell w/ the helmet is on.
After my ride today, I put the kickstand down at took my helmet off to listen, and I can hear no popping, though it might be there, barely perceptible. Maybe just the carb sync?
And it's so recent after my rebuild that it hasn't had the chance to blue or yellow the pipes at all.
Since I do have an idea what's going on and I think it's real close, I haven't done any plug chops.
Also, choke at idle will kill it. I have yet to observe any fuel mileage.
I'm thinking I need to go up a size or two on the idle jets.
I want to take the easiest observations first. I'm thinking:
1. Do the with and w/o filter test.
What next? Input please.