My doggy mercury

[target62]

I have a 1989 90 hp 3 cyl. on a 28 ft. pontoon boat, sometimes when I first start it up and head across the lake it will olny run about 3500 rpm and acts really doggie, then like a snap of your finger it will take off like a rocket and run perfict all day. it dosn't miss when it acts doggie but it just won't build any rpm. I replaced the plugs, but that didn't help. dose anyone have any ideas?? thanks.

 

[outhere99]

Re: My doggy mercury

I'd start looking at the fuel system. How old is you fuel hose/bulb? Maybe it's time to clean out the carburators...etc.

 

[target62]

Re: My doggy mercury

Fuel hose is new, don't know much about cleaning out the carbs, so havent done that. the tac. seems to act like it might have a short in it, it dosent always work. could that cause the problem?

 

[mthieme]

Re: My doggy mercury

I have two suggestions - Fuel Pump kit and float.
The fuel pumps are a weak area on Mercs.
The plastic floats have a seem that fails. The replacement is solid foam.
Both items will exhibit the symptoms you describe.

 

[target62]

Re: My doggy mercury

I have put on a new fuel hose and bulb, also put in a fuel pump kit and drained the carbs. now I have a new problem, it acts like it is running way to rich, and it is hard to start. when I get it running it still acts like it has it's doggy problem as it is very slow to build any r.p.m. when I trim the motor all the way up, should the gas run out of the carbs? mine does

 

[bigred69]

Re: My doggy mercury

Sounds like the carbs are gummed up. When you drained the bowels and refilled them it could have broken some junk loose in the bowel puging off the tiny passages in the carb. Also the carbs should not leak the needle and seats have trash in them. Rebuild the carbs.

 

[target62]

Re: My doggy mercury

not sure what I did, but I got it to run. I took off the carbs and kited them but they looked like they were brand new the olny thing I might have done was I lowered the float level a little as I thought they might of been a little high any way it runs good now. thanks for all your good advice it was sure helpfull

 

[bigred69]

Re: My doggy mercury

Good job man !!!!!!!