Fuel pump issues

jslu

Seaman
Joined
Jul 31, 2010
Messages
74
1987 35 HP MERC SERIAL NO. 0B111943

The serial no. posted above would indicate model year 1987. However the power head exhibits a configuration used in 1986. Either a power head swap or early 1987 model with leftover 1986 parts from Merc. This serial no. is early in the model year by 1000+ units ????

That being said, here is my problem and questions. I have another of these 1987 Mercs and it has the "square" type fuel pump, no problems. The above mentioned fuel pump from 0B111943 has the "triangle" fuel pump of which there are 2 versions, see photos.

First question. Notice the gasket in place on the pump, obviously different config. I was assured by my local Merc dealer that this gasket superceeded the older version and would work on this pump. I am not convinced after understanding the mechanics of the pump sequence. Anyone have experience with this gasket replacement for this pump????

Second question. The spent cooling water from the engine block is routed from the lower left rear of the engine block (viewed from the rear) through the pump then out to the "pee" hole. Anyone know why? Anti vapor lock? Pre heating fuel?IMG_3413.JPGIMG_3414_1.JPG
 
Last edited:

Laddies

Banned
Joined
Sep 10, 2004
Messages
12,218
Re: Fuel pump issues

Thats definitely the wrong kit, that is the kit for the 3 cyl 50-60-65-70 engine merc #55278A4 or sierra # 18-7809, you need merc #55278A5 or sierra #18-7808 your pump is water cooled and the other is not that gasket would let the cooling water in your crankcase.
 
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