low hour mercury 40hp 2 cyl with starting problems

[d_glover25]

First off, the motor has 20 hrs. and has been sitting for a year. When I started the motor it ran for 10-20 seconds and died, over and over. I changed the fuel tank and and hose and found dirty fuel and leaking hose. still it wont start for long. I checked the fuel filter and after that, it wont start at all. I have no idea what is wrong. the fuel filter was good, very clean, by the way. I tried carb cleaner and found that I could keep it running for as long as I kept spraying in the carb and then it would die as usual. I decided it would be a good idea to check compression again since I found the good tester that had been lost. compression was same in both cylinders, but the bottom plug was clean. I thought it was the carb cleaner. I decided to rebuild the carb with new gaskets and found gum and varnish around th jets. soaked the carb in cleaner and tried to restart. It started at an extremely high idle with the first try. Maybe three more times it started at very high throttle. So I do the linkage adjustment and make sure everything is straight. Now its back to not starting at all. The battery is good and it turns over very strong, but no start. I've read the manual and found nothing like my symptoms. I have found that the fuel pump with a busted diaphram could cause fouling of the plugs(wich are new). but is fouling the same thing as cleaned or wet? I'm really at a loss. the engine is like new. The tank, line, and carb are all good, the only thing left is the pump. is there anyone who knows something about mercs and could lend a hand? I'm really stumped. Please help.
Thanks in advance!

 

[WillyBWright]

Re: low hour mercury 40hp 2 cyl with starting problems

It sounds to me like the carb still has a blockage. Sometimes a blockage leaves an air pocket when soaking and the fluid never reaches all of the varnish. After soaking, spray carb cleaner through each and every hole and orifice you can find and make sure it comes out someplace else. Also make sure there is no water in the bottom of the fuel tank. Prop it so that the fill hole is low, then syphon from the low corner of the tank until you have clean gas.

A spotlessly clean sparkplug usually means it's not getting spark.

Instead of using carb spray to start, use a spray bottle with premix fuel. Carb spray washes the oil off the moving parts which can cause serious damage.

Rebuild the fuel pump. Old diaphragms dry out and get stiff and brittle. Kits are cheap and the task is simple.

 

[d_glover25]

Re: low hour mercury 40hp 2 cyl with starting problems

Thanks Willie,
My motor runs now and I'm about to start with timing and syncronization. I have the manual. I need to get some tools and guages. Any suggestions or tips with the process? Things I should look out for?