Fuel pump kit cross-over

The motor is an 85EL77, 1977 Johnson 85HP.

See the previous thread regarding fuel system problems I had today. (http://forums.iboats.com/showthread.php?t=434536)

Thinking about changing the fuel pump since it hasn't been done since I inherited the boat just as preventative maintenance.

Trouble is, fuel pumps are $$$, so I wanted to just get a rebuild kit.

No rebuild kits are specified for this year/model of engine that I can see, and the factory service manual says the fuel pump is serviced as a unit.

However, according to the shop.evinrude.com site, the pump for the 1978 85HP is a 0385784

Take a look at the 75HP model for say, a 1980 motor: same pump number. 0385784.

Take another look at the 75HP model for 1975: same pump number, 0385784.

Now the strange thing is, you can find carb kits for the 75hp model for those years, both 1975 and 1980, and they are the same.

Does it stand to reason then, that if the entire pump is the same part number for the 1977 85HP as well as the 1975 75HP and the 1980 75HP, then the pump rebuild kit for those 75HP motors should work on my 1977 85?

It looks like it's some sort of oversight in the parts application book, but I can't be sure.

--Geoff

Re: Fuel pump kit cross-over

personally, as the owner of a Johnson/evinrude service company, i do not rebuild fuel pumps of my personal or customers motors. there are too many "if's" when this is done.

it sounds as if your motor does a lot of sitting, rather than running.

1/ fuel hose connected with arrow on bulb, pointing toward the motor.

2/ is fuel new, or old as the last carb job?

3/ built in or portable fuel tank?

4/ have you check spark and compression, with testers?



lots of good stuff here? http://forums.iboats.com/showthread.php?t=299680

Re: Fuel pump kit cross-over

Yes, the motor sits more than it runs by far.

The fuel tank was refilled from empty yesterday before going out on the lake. It is built-in.

The primer bulb's arrow points in the proper direction. As noted in the other post, however, it never gets firm, and a test yesterday when the engine was stalled revealed no fuel coming out of the hose when squeezed.

Have not checked spark nor compression. I guess it is worthwhile to do so, but I doubt I'll find anything wrong there. I will do so before throwing parts at this though.

Thanks for the reply and the link to the FAQ; I did read them before posting.

By the way, it just so happens that I have those exact testers your pics show. 7/16" gap on the spark tester right?

Re: Fuel pump kit cross-over

Okay, it took me a few days to get the time, but today I gave things a good going over.

Compression seems fine: 112, 118, 112, 106 (that low number is still close enough, isn't it?)

Spark is strong. Each coil produced an arc over a 7/16" gap.

Fuel pressure is fine. I teed into the output from the fuel pump and connected a fuel pressure gauge. Pressure is between 2 and 2.5 PSI at idle and at higher RPM (2-3K).

The fuel tank is built in on this boat; there is a through-hull fitting in the motor well I removed and blew through with compressed air. No blockage. No blockage in the tank vent either.

I only found one strange thing. When I was done blowing through the lines, I picked up the length of hose with the primer bulb in it. When I rolled the primer bulb around in my fingers, I could feel something rolling around inside, moving the full length of the bulb. So I disassembled the primer bulb and found a circular piece of plastic with a hole through the center of it --an orifice about 1/4"--that had come loose from the output side check valve. Try as I might, I couldn't come up with a way that it could have blocked flow through the bulb, but it definitely wasn't right.

Reassembled the primer bulb, oriented it properly with the arrow pointing toward the motor, gave it a few dozen squeezes. Still would not get firm. Opened up the gas cap and put my ear to the filler as I squeezed the bulb...heard what sounded like bubbles blowing in the tank when I squeezed the bulb.

Is it possible that this primer bulb could be cutting off the fuel and starving the engine at higher RPM? At this point, having found something loose inside, and now with it not actually priming, I'm going to replace it, but I'm wondering if there is something else that could be the problem?

Help please?

--Geoff