Leak Bottom Plate diaphram assembly F15MSHZ Carb.

[captaindarrell]

I am new to this forum. So here is my first post.

I have a F15MSHZ four stroke that constantly needs some TLC. I have cleaned this Carb many times and carry a spare carburetor for the Dinghy motor. I have installed the water separator and store the engine as well as possible. We learned our lesson with Ethanol Fuel. As you can tell- i am a little frustrated with the Engine

This last time I cleaned the Carb. I developed a nasty fuel leak in the bottom of the Carb. This is the plate that holds the Diaphram Assembly. There are no gaskets and all screws are snug. Could there be a problem with the diaphram or a clogged orifice? If i push down manually on the diaphram- even more fuel squirts out. Any help would be appreciated. Thanks
Darrell

[boats.net]

It needs to be taken apart and see if diaphram is bad.

[captaindarrell]

Thanks
What typically makes a diaphragm look faulty. It seams like a part that would
Be Difficult to break.

[99yam40]

The diaphragm can be damaged when the motor lean sneezes (backfires)

[captaindarrell]

Thanks

I will order a new one. Shouldn't be to difficult to swap out.

[captaindarrell]

I changed out diaphragm. And still have the leak. Could I have installed the diaphragm wrong? It Seemed pretty straight forward. Now I have lost power. It still starts and idles just fine. I do seem to be making oil. I changed oil. Lowered the proper level. Very frustrated. Any more thoughts

[captaindarrell]

I changed out diaphragm. And still have the leak. Could I have installed the diaphragm wrong? It Seemed pretty straight forward. Now I have lost power. It still starts and idles just fine. I do seem to be making oil. I changed oil. Lowered the proper level. Very frustrated. Any more thoughts

Sorry I forgot the most important part of the thread.
When I swapped out the carburetor to my spare- I get the same leak at the bottom of the carb and have no power in gear. About ready to throw this one overboard and purchase a new Suzuki 9.9.

[99yam40]

I just looked at a parts break down of that carb and I have no idea what the diaphragm is for or does, but maybe the fuel pump is leaking and that is causing some of the problems

[captaindarrell]

Interesting that two carbs are now leaking in the same spot. There are two small rubber rings. But they look good. I can live with the leaks temporarily.
But the lack of power is not making me happy. Is there a computer chip in this small of an engine? The engine runs forever at slow speeds. checked the plugs.they are ok.

[captaindarrell]

No high rpms 15 hp 2001 four stroke

I recently posted about a diaphragm issue. Hopefully I did not alienate too many users. We are currently in transit and the motor is on our tender. Taking it to a shop is not on our schedule.
The motor does start and idles just fine. I can't get high rpms in or out of gear.

I can purchase more parts when we land in port. Where do I start?

Fuel pump, a computer chip or other module. Or higher octane gas.
I was able to get higher rpms when I ran Valvtect into the fuel line. But that was only momentarily.

I changed out hoses. Should the bulb primer stay hard all the time? Mine might nit be doing that. I don't want to throw too much out there and confuse the issue further. I have changed all the parts in my main carburetor and my backup.

[99yam40]

Take the pump apart and inspect it for problems.
Primer should get hard when priming , but will get soft when fuel pump starts to suck fuel through it

Testing is the best way to find a problem instead of just replacing things, but do what you have to

A motor needs good compression, good spark , and that spark has to happen at the right time(timing), and the right fuel /air ratio to produce the HP.
Test everything you can to eliminate those things and then work on the ones you cannot test

[captaindarrell]

Thank you!