1999 75 horse merc/force

[mdbasser]

i bought a used 1999 bass tracker with a 75 hp merc/force on it and i have never been able to get it to run right. i changed the lower unit oil, changed the fuel filter and the plugs. it is running better then it was but it is still having problems. at idle it will die out, and at full throttle it sounds as if it is missing. and sometimes it becoming more often then not, it will not turn start right away. it is tring to turn over but it isnt happening. the last time this happened i grapped the fuel ball and it was soft. arent these supposed to be hard the whole time? im thinking that it may be the fuel pump going. and i have heard bad things about the reliability of merc/force motors. if anyone can help out i would be very thankful for the insight.......Rob

 

[roscoe]

Re: 1999 75 horse merc/force

Replace the fuel line starting at the tank, including the bulb.<br />Rebuild the fuel pump ( $10).<br />Empty out the gas tank, could have water, sludge, or debris.<br />Do a thorough decarb of the engine. <br />Then check the compression.<br /><br />Decarb Process:<br />Your intent is REMOVE the existing carbon buildup from the cylinders, heads, and rings, a spray decarb solvent product, such as SeaFoam Deep Creep, is needed to do the decarb process. Some people use one can per cylinder.<br /><br />Run engine at fast idle, with engine running, slowly spray liberal amount into each carb, its gonna smoke up the place,<br />spray for a couple minutes, now spray a larger amount into carbs until engine chokes out and stops.<br /><br />Remove spark plugs and spray decarb liberally into each cylinder, install the spark plugs, let it soak for 1 to 6 hours. <br /><br />Start the engine and run at medium throttle, or if at the lake, run it at full throttle. It won't hurt to spray some more through the carbs. Run it for atleast 10 minutes to flush the crud out of your engine. Now remove and clean, or replace the spark plugs. <br /><br />It works well to do the spraying, the night before you go to the lake. This way you can let it soak overnight, and really flush it out at the lake.<br /><br />Don't do this in front of the garage door or the house, unless you want it coated with greasy crud.<br /><br />If this doesn't help, then rebuild the carb.

 

[mdbasser]

Re: 1999 75 horse merc/force

thanks for the info...sounds like you have done or told people to do that alot....are new plugs ok to use right from the box or do they have to be gapped? i didnt gapped the last ones and i threw the ones that were in the engine out when i changed them without thinking to look at them.

 

[roscoe]

Re: 1999 75 horse merc/force

I always check the gap. You never know if they may have been hit against something or a mistake was made at the factory.<br /><br />I decarb my engines more than I should, because i can't afford to have one seize up.<br /><br />I am convinced that if everyone would decarb, like the owners manual suggests, that many of their engine problems would never happen.