I have a 1997 Fountain with twin 500hp carb motors all stock. Where is the best place to connect a vacuum gauge. There is a rubber line that comes from the front of the base plate on the carb and goes to the left side under the electric choke. Can I tee off of that line or is there a better place. I cannot find any ports on the manifold or any other places on the carb.

Theres two types of vacuum, ported and manifold. You need manifold. At idle pull off vacuum hose and check for vacuum. If it has vacuum at idle its manifold, tee off and use it.

How about a tee in the line that goes to the pcv valve ?

I cannot start the engines until spring. They have been winterized. The gauges are already in the boat but they are not hooked up. I just want to hook the gauges up so everything works.

At the very top of the intake manifold in the front there is a plug , pull it out and screw in the proper size nipple . If you use the one on the carb make sure it is located below the throttle plates . Why do you want to measure vacuum ?

The PCV hose is braided stainless. I could use that line but I would have to find the right fitting to adapt without screwing anything up. That line is very ridgid. I guess I am looking for a easy fix,,,,,yea right !!

Then i'd use the port that ''the deep'' mentioned. Remove plug, insert proper fitting

I bought the boat last fall. At one time in its life it had blower motors and it had fuel pressure and vacuum/boost gauges that were left in the console but are not hooked up. I want to hook these gauges up so everything works.

I may have some fuel psi electric senders available, might go mechanical on my fuel psi.

I didn't see that port. Not saying that it is not there. I will check it out. Sounds like the easy fix that I am looking for.

thanks. I will post what I find.