TOPIC: 1960 Merc 400 question

Took her out today and she ran fine up to 5000 rpm about 4/5ths throttle once I went over that the engine slowed down i could pull the throttle back and Rpm would go back up then down. It was like she just laid over. The engine lost its crisp sound it didn't die or miss it just slowed down to about 4600 rpm but was not crisp sounding i thought fuel but normaly it won't pick right back up if it is a fuel issue and ignition normally causes a miss.
Any Ideas.
Also I just about flipped her when I was goin about 28mph and a wake boarder screamed by and I hit its wake. I don't know how fast it was going but it had to be pushing a 4ft wake.
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max spark advance set to high ? should be .235.

Thanks Dave i will check that out.
My motor doesn't have a Magneto stop bracket Per Tim Calmes. It just uses the phillips screw adjuster. Maybe I didn't get the jam nut tight and it vibrated out of adjustment.

I checked the timing and it checked ok. The plugs are wet with fuel but the insulater tip is a nice tan.
Now here is a real stupid question on the old merc cans is the vent open when it is unscrewed or when it is tight against the cap?
I ask this because with the tank full t started to act up with the vent un-screwed all the way so I screwd it in part way and it ran great. Still with a wot issue but not as bad. Full throtkle gave 5200rpm but still pulled over.

The vent is open when all the way open (counter-clockwise)
If the fuel tank is not low on fuel, the prime bulb valves are properly working, and the pick up in the tank isn't plugged with rust, etc,...It sounds to me like the fuel pumps need to be rebuilt.
You may need to replace the valves in the fuel pump, as well as the diaphragm kit.
To test the fuel tank - wedge a small screwdriver into the female connector at the motor so that the steel ball in the fitting is held open a bit.
Then (with the engine end of the prime bulb pointing up & the female connector pointed into a bucket or can of some sort to catch the fuel) squeeze the prime bulb repeatedly until you get a full stream of fuel mix. If you can not get a series of full shots of fuel - you'll need to look deeper into the tank & fuel hose.
If you are getting a strong solid shots of fuel you will probably resolve your problem by R&R'g the fuel pump.
Doc

Hi Tom, Dave, & Thom,
Tom to add to Dave's and Thom's good advice, you might want to check carburetor float levels. As the sealing material of the inlet needle & seat assemblies swell (from fuel exposure), this lowers the fuel level in the float bowls. Although the float adjustment can be reset, I would advise the installation of new inlet needle & seat assemblies as well. Do inspect the floats for cracks or distortion while you are at it.

Regards,
Joe
www.fergusonpoolemarine.com
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I still haven't got to the carbs yet but I took her out today and the change of plugs made a big difference (old plugs looked good). So did removing the cap on the tank.
So a fuel pump kit, new gasket kit for the gas can cap, and carb kits are on order. The gas cap needs new gaskets anyway I made the ones on there out of gasket paper but found a cap rebuild kit on line.
Does anyone know where I can find gaskets for the fuel can pickup assembly I want to remove it and clean out the pickup.