Can I rule out fuel pump now ? - 1987 90HP

[bang4dabuck]

I have been going through some stuff on the fuel side and for a while was looking at testing my fuel pump (but was avoiding buying that expensive OMC tool needed). Anyways on this project motor, that has been pretty much sitting around for nearly three years, it would start up on muffs. It would take a while to catch and not stall out but I just figured it needs to be fine tuned and so I started concentrating on trim and thermostat issues. So after these seemed to be under control ( a couple weeks later) I went to start her up. She would just stall out and then eventually just crank not even close to starting. I tried the gas lines at the same height and making sure ball stayed hard and after cranking and cranking and priming and back and forth on the throttle linkage I could not smell gas. That led me to believe there was a fuel pump problem.

Today I did the spray premix in the carbs deal and she pretty much started right up an then stayed running. I turned her off and cranked her again but no go. I sprayed again but no go. I squeezed the ball and watched the carbs because I noticed ball wasn't staying hard. Gas was dripping out of the carbs as I squeezed. So is this pretty much a carb issue and not fuel pump ?

 

[wilde1j]

Re: Can I rule out fuel pump now ? - 1987 90HP

You can test the fuel pump with a 0 to 15 psig pressure gauge and appropriate fittings ... nothing fancy.

 

[James R]

Re: Can I rule out fuel pump now ? - 1987 90HP

When were the carbs last cleaned? I would bet that is your problem. The carbs need stripping and soaking in Gunk products carb and parts cleaner and new carb kits fitted.

 

[bang4dabuck]

Re: Can I rule out fuel pump now ? - 1987 90HP

I just got one of those 15 PSI gauges today. I will have to figure out the the layout with fittings and hoses.

Sorry you guys. I pretty much got to face my demons. I got a fuel issue and a overheating issue. I was warned here that two things I should do right away was change water pump and rebuild carbs. I haven't done them. I bought all the kits but feel intimidated especially on the carbs, kind of gray. Seems like there is no set procedures to do it. Anyways I got the manual and the net so got to do it. Overheating - I still think its going to end up being the waterjackets since I just changed out the thermostats but we'll see. If I can get these 2 things done without anymore SELF INFLICTED WOUNDS (just broke a spark plug wire putting cowling on and my engine didn't want to turn off after just putting on new ignition switch ... not good when she's running hot), I think I'll be almost there.

 

[tashasdaddy]

Re: Can I rule out fuel pump now ? - 1987 90HP

top secret file. http://forums.iboats.com/showthread.php?t=299680, changing the impeller, and tstat should solve overheat, problems, but have you checked your compression, if it has a blown head gasket into the cooling system, that will make it run hot. replace the fuel lines, and disable the vro oil side, and premix your fuel.

VRO conversion w/ pump still working

if the fuel side on your Pump is still working it is very simple. unplug the 2 line harness going to the oil tank, unplug the 3 or 4 wire harness, going to the Vro pump. cut and cap the oil line going into the motor. add oil to fuel tank, mix well, then remove fuel line at top carb, catching gas in a container, pump the fuel line bulb until you get premixed gas to the carb. you can tell as it will change color. put line back on carb, and go boating.

 

[bang4dabuck]

Re: Can I rule out fuel pump now ? - 1987 90HP

Did a compression check 2 weeks ago, all 4 were in the 140's. After this last episode I will check them again.

Will rebuild carbs first and then go after VRO if there still is a problem. I did plan on disconnecting oil tank but want to do it as prescribed.

Going to Fairwinds now to pick up Triple guard, adhesive M, OMC nut lock, Locquic, Screw lock, permatex 2.

Here I go.