vacuum line on 69 lark 40 hp

[charliedaubitz]

Directly under the carb is a vacuum port with a rubber hose on it that's unconnected my motor. Any idea where it goes? I have a vacuum line on the vac switch and it's connected, do 2 lines go to the switch? I had the carb off and looked over the choke and didn't see a barb for it anywhere. The choke is a hot air choke, what induces the hot air flow?

 

[tx1961whaler]

Re: vacuum line on 69 lark 40 hp

The larger vacuum line goes to the vacuum cut-out switch. The smaller line is an oil recirculation line, which runs from the base of the motor under the carb to the top of the crankcase, starboard side, just under the armature plate.

 

[F_R]

Re: vacuum line on 69 lark 40 hp

As for the hot air, there is an air passage built into the carburetor, goes through a hole in the flange gasket into the intake manifold.

 

[charliedaubitz]

Re: vacuum line on 69 lark 40 hp

Thanks to both of you, this site is just too cool, I think this fix my idle issues. I know it will help. I used the search utility to look for vacuum lines and didn't find any posts, seeing all the idle issues here I would have thought on a older motors this would be a common problem.

I have another question, this is a 40973R motor, I think it's a 69. On this carb, I have had it apart a few times, I made the jet tool to remove the jet behind the bowl drain plug. It was plugged. Is there another removable jet? I have the cork float but for now it and the viton tipped neddle and seat aren't leaking, the bulb pumps up and the fuel pump pumps. On the main well bottom there is what looks like a jet, is that the main jet? Is the jet behind the drain the idle jet?

 

[F_R]

Re: vacuum line on 69 lark 40 hp

The high speed fixed jet is the one deep in the hole behind the drain plug. The slow speed jet is the adjustable needle valve. That's it.

The large brass tube thing running verticle is the main nozzle. It's only requirement is that it be clean.