1976 Johson 15 HP fuel pump rebuild

[Seahorse16]

Ok, so I finally got my fuel pump kit in. I carefully removed the inner diagphram etc from my existing one and started to replace parts. I wasn't confident it was done right, so I found an image online (picture attached) of the steps to rebuild this fuel pump. Here's the problem, my existing one did not contain several of the numbers in the diagram!!! I did recieve these parts in my kit, so I put them in. Was that a mistake?

My current pump did not have #2, it did not have the spring that pushes the button on #3 (but it had the button), it did not contain gasket #5 either.

So I put #2 on, I put the spring under the loose cap in #3, and I put in #5. Did I do this right? Or are these extra gaskets for different pumps? I was just following this diagram. Could that fact that I did not have a spring be the cause of my fuel pump issues? Lastly, there was a tiny spring and a tiny cap that I could not find a home for...ideas?

Thanks,
Trevor

 

[OptsyEagle]

Re: 1976 Johson 15 HP fuel pump rebuild

I can't answer all the questions except I know there is a spring in there so if yours didn't have one, putting one in should not hurt.

One of the best tests for a fuel pump is the blow test. Put your lips on the intake nipple and when you blow air should flow freely and when you blow into the output nipple the air flow should be fully restricted. This doesn't guarantee the pump will work but if it fails this test it definitely will not.

 

[racerone]

Re: 1976 Johson 15 HP fuel pump rebuild

The factory repair kit comes with complete instructions.--Including where the outlet of the pump should be and which pocket has the wee spring.--This pump can only be mounted in a specific way.

 

[Seahorse16]

Re: 1976 Johson 15 HP fuel pump rebuild

Thanks. I will try that test. My repair kit came with 0 instructions.

 

[OptsyEagle]

Re: 1976 Johson 15 HP fuel pump rebuild

Rebuilding the OMC Fuel Pump

 

[Crosbyman]

Re: 1976 Johson 15 HP fuel pump rebuild

I like to just touch the little mushrooms (domes) with crazy glue to secure them on the springs and then glue the springs on their respective base nipples before trying to position the diaphragms in place.

The glue prevents the springs from tipping over and boost your self esteem because of fat fingers.

BTW... read the instructions 3 times.... that helps to

 

[OptsyEagle]

Re: 1976 Johson 15 HP fuel pump rebuild

so do small fingers.

 

[Seahorse16]

Re: 1976 Johson 15 HP fuel pump rebuild

Nanny called in sick today, so that means I get an unscheduled day off. I only had a 40 minute napping window to get this done, but I think I pulled it off. To start, my pump did NOT pass the blow test so I knew I had issues. Amazingly, the pump I had did not have EITHER spring! Makes sense it wasn't working right.

There is no way in Hades I would have ever properly got this set up without OptsyEagle's link. Thanks! Also, the glueing the domes to the springs was also a serious necessity. All in all, everything lined up the way it should, and I passed the blow test this time. If I can get the kitchen pass tonight, I will try and run it in a barrel to see if this solved my problems.

Thanks again!