1978 500 50 fuel pump

[willy01]

I have a 1978 merc 500 50 hp. I ordered a rebuild kit fot the carb and had more pcs than my existing carb. the fuel pump from the carb body out it had a gasket a rubber Piece with 2 small flaps on the bottom. but when I got the kit it had a yellow fiber piece too that my original cab didn't have. is this yellow piece supposed to be there. the motor runs good on muffs but in the water I can't get any rpms out of it, I though maybe the yellow piece was restricting the pump.

 

[racerone]

Doubt it.-----Post your compression values here.-----Does spark jump a gap of 3/8" on all leads ?-----Replaced the water pump impeller about every 5 years?----Inspect exhaust under powerhead for blockage.

 

[willy01]

compression looks to be around 125 on the top 3 cylinders, can't get my tester on the bottom one but put my finger on it and it feels like good compression I'll have to see if I can borrow a angled one. I pulled yellow fiber piece out and broke the damn coupler reinstalling the carbs... a little epoxy and I'll check spark tomorrow. my biggest concern was that yellow piece in the fuel pump. I see it in some kits but not others. I see on exploded diagrams that it not there so I took mine out and will fire it up tomorrow. new impeller last fall, peeing good.