1967 33hp Skitwin carb adjustment

[Boat461]

Had the motor in water last weekend and ran good. Tried today and it wouldn't rev up under load. Would rev up in neutral but in gear fwd or rev would not. It would idle. Pulled the plugs and they we're soaked. Running fule about 20 or 32 to 1 ran extra oil cause I didn't know and didn't want her to blow. Was running to fuel rich, but high idle adjuster didn't make a difference. Where should throttle set screw on link be set that adjusts spark. Have new plugs and haven't checked points. Please help.

 

[Joe Reeves]

Use a good quality 50/1 oil....... mixture should be 50/1, 1 pint of 50/1 oil to 6 gallons of gas. You're using way too much oil!

 

[Boat461]

I was using synthetic marine 2 stroke oil. Whatever name brand Walmart carried. Is there any reason to use synthetic vs standard?

 

[Boat461]

Any idea about the throttle linkage positions?

 

[F_R]

If you are talking about the rod that runs along the port side of the powerhead, don't mess with it. OK, so it probably is the most messed-with part on the motor and somebody might have already gotten to it.

1. Motor in forward gear
2. Advance throttle till the magneto plate bangs up against the stop on top of cylinder block. Don't force beyond.
3. Vertical throttle lever should now just touch the setscrew barrel. If not, adjust it so it does.
4. Now continue to move throttle (cams over and pushes on the rod/setscrew) Carb should go wide open.

 

[Boat461]

Thank you F_R, that is the linkage I was talking about.anytjimg elso I should look to readjust? This was previously run by someone that was not a "mechanic" type. I am a car guy, out boards are not my thing.

 

[jimmbo]

Initial settings for the Mixture screws are; 1 1/2 turns out from LIGHTLY seated for the Idle mixture needle, 1 turn out from LIGHTLY seated for the High Speed Needle. Warm engine up and at WOT adjust High Speed needle for best speed, then slow to idle and adjust low speed needle for smoothest running at idle, recheck high speed adjustment

 

[F_R]

If it was running good, then not good, that stuff didn't just get out of whack by magic. Best you do a spark test. It's probably running on one cylinder.

 

[Boat461]

I was thinking the float may have gotten stuck or something. I had adjusted the set screw barrel the day it ran good so that it would go to wot, it worked after that, but that may have messed it up then. Going to pull the carb off and check it all out. When I pumped the prim ball gas came out the front of the carb. That would suggest incorrect float height or bad needle seat, right?