[May70]

I set the dwell to 31 degrees.

Timing is at 12 degrees of advance.

The oil does not smell like gas.

See pics of spark plugs. I just put these maybe 1.5 weeks ago and havent really driven it more than around the yard while Ive been working on it, starting it up, letting it idle etc. First two looked wet and pretty bad, the rest blackened but lessened as you can see in the pics toward the back cylinder.

When I first started it cold the rpm wass between 830-900 for the first ~ minute. After it warmed up it went up to 1050-1100 ish just at idle. This was with the fast idle cam on the fast idle notch and the mix screw 1.5 out. I couldn't get the rpm to change with adjusting the mix screw, so I adjusted the fast idle to get the rpms down to 700ish with the engine warm. I just came inside and read my pdf manual and it has a altered approach here:

L6 Engines • 20 and 30 Series
Manual Transmission
Disconnect and plug distributor vacuum line.
Turn mixture screws in until lightly contacting
seats, then back screws out four times.
Adjust Carburetor idle speed screw to obtain 600
rpm with manual transmission in neutral.
Adjust mixture screw in to obtain 550 rpm with
manual transmission in neutral.
Reconnect distributor vacuum line.


I figured I would try this...
I took that as put the mix screw out 4 rotations from seated. And adjust the fast idle screw again to get the 600 rpm. Im a little confused though because I only have two screws and hope I am getting this right. One mixture screw on the front and fast idle screw on the back side, as ive seen them called out. I then adjusted the mix screw in to get roughly 550 rpm and here is what happened:

Mix Screw Adjustment (Rotations out from seated), RPM, VAC (in Hg), Notes

4, 600, 20
3.5, 600, 20
3, 600, 20
2.5, 600, 20
2, 650, 21
1.5, 680, 21.5
1, 600, 20
.85 (estimated), 580, 20 ** Returned to this adjustment**
.75, 550, 18, Rough idle & vac dropped off jumping around 17-18


I checked the distributor vac canister. I dont have any hand pumps but I put a long vacuum line and a syringe on it with absolutely no change when putting a vacuum on it that way. I then took the syringe off because I wasn't sure if that was creating enough vacuum so I sucked on it as hard as i could and there was no change at all. I could blow into it and hear a little air whistling down at that canister. I also pinched the vac line and gave it a rev and nothing changed again. Dwell sat at 31 deg.

I sprayed carb cleaner on the back of the carb and it does ever so slightly increase the rpm. But I have to spray a lot to get it to do that so im having a real hard time narrowing down the location.

As geezer has mentioned my float might be sinking. It is brand new and I was very careful with it while adjusting the tang exactly how the carb instructions said. I will be pissed if that black float is leaking. I guess when I take the carb apart Ill check it in hot water.