It's made of thin rubber and won't be surprised if it's a very old stock, dried and brittle. Yup, I've seen others replaced them like every two weeks for 3 times. Ultimately got a real good one.
One little backfire or cough can hurt the diaphragm.
Buying at the dealer you can get something that's been on the shelf for years??
Was doing routine maint. on a customers boat.
Pulled the pump and was going to change the diaphragm.
Much to my surprise!!! it came apart and had 2 diaphragms in there.
There wasn't a problem.
It was working great.
Possible. Remember, the primer bulb doesn't have to get "hard" (highly subjective) instead it just needs to become firm to indicate you have filled up the bowls. And "firm" is relative to when you first squeeze it.
I pulled the other fuel pump off this morning because my new parts are to arrive today and it also had a torn diaphragm! So I guess the back fire sounds right on. They are really thin. I have never touched the timing adjustment on this engine but I am thinking maybe I better make something up to ground all the spark plug leads so I can verify timing is right. If it was a back fire condition that caused them to tear I don't want it to happen to new diaphragms! Thanks for all the help! I'm learning a lot from reading all the post on this forum.
Back fire can happen to any of these motors.
Too much fuel in the system(torn diaphragm)
Get them from someone who sells the OEM products.
The dealers stock could be there for a while?
But that's where I'd look first.
Call and see if they have them in stock? if they don't?? ask them to order you 2.
I bought these Im putting in on this iboat forum . Hope they are good one. Put them in today and once I got the cylinders cleaned it started and sounded best it has in a long while! Now I just have to wait to get it out on the water with a tow boat following me just in case! LOL
Went to go out today and cranking was slow and would not start. Battery is new and fully charged so I put a 110volt charger with a car starting setting on it and engine cranked like new and started right up. Cables got warm from trying to start it in the beginning. Once it ran for 5 minutes or so I turned it off and restarted it with just the battery and it started immediately! SO now I have tried two batteries in parallel and it cranks Great! Think I a starter going bad. I tried jumper cables with the one battery but same results as the beginning very slow cranking and I guess high draw on battery! Well at least the engine sounds great now!
I bought a boat with a 88/85hp and found 2 batteries hooked together.
Turns out the lower unit bearings were trashed.
Took 2 batteries and starting fluid for the PO to get it started.
I changed the lower and the problem was solved.
Good information to know thanks! Funny part is once the motor starts I can turn it off and it starts with one battery within a second. I'm thinking it the starter because I can move the flywheel by hand. Probably all the cranking between two sets of bad fuel pump diaphragms was not great for the starter. Its the original starter. Thanks for the help!
