motor problems!

[LPfishnTIM]

I got a 25 mercury 96 model, It will start up fine if you prime it and give it some gas with the choke pulled, it will run on choke with high idle and will even run on medium idle but will not run without giving it a little gas and with the choke pushed in (like it should be after being started). I took the carb off and checked the jets all are clean as a whistle but I sprayed carb cleaner on them anyway. I installed the carb back on still same crap! any help will be appreciated. also I checked the fuel filter its good. could it be the fuel diaphram.

[Ray]

If it was the diaphram, it will run if you keep pumping the bulb.
You said you checked the jets, but it sounds like it is plugged or partially plugged.
Try pulling the jet and using a tip cleaner.
If she runs at high speeds or choked/partially choked, it sounds like the jet.

[LPfishnTIM]

it won't run faster than 10mph because it won't run w/o being choked

[B-Stealth]

I have the exact same engine and its in the shop having the fuel diaghram replaced; my engine would not fire.

[Gerald]

I would take the fuel pump apart to check the diaphram.......sounds like it could have a crack in it.

If fuel pump is ok.....

Like Ray said---- I would take the carburetor off and spray some carburetor cleaner through each hole in the carbretor to be sure you get good flow. Some of the holes maybe hard to get to.....but keep trying. Be sure every pathway is clean.

Let us know what you find. My money says it is a bad fuel pump diaphram.

[Kenner18]

Never use a tip cleaner to clean out jets in a carb. Tip cleaners are like a file and will increase the size of a jet if not extremely careful .I generally use small wire since it has no abrasive properties. Also berryman chemtool carb dip is very effective to remove gunk from carbs . Most parts houses have it .
I've had similar problems and it was the diaphram in the fuel pump ,but its not always the case.

[Hebert]

pump the bulb when it starts dieing...if that keeps it running then its your diaphram....if not..take apart your carbs and clean them and put a rebuild kit on them...best way to clean your jets is blow high pressure air through them...anything else and you risk scoring them up...

[LPfishnTIM]

Originally Posted by Gerald

I would take the fuel pump apart to check the diaphram.......sounds like it could have a crack in it.

If fuel pump is ok.....

Like Ray said---- I would take the carburetor off and spray some carburetor cleaner through each hole in the carbretor to be sure you get good flow. Some of the holes maybe hard to get to.....but keep trying. Be sure every pathway is clean.

Let us know what you find. My money says it is a bad fuel pump diaphram.

My diaphram has a crack in it, ordered one today should be here in two days!