115 merc 4 stroke

[backdraft]

Went fishing today and followed a guy with a new 115 merc 4 stroke. He had to limp back to the dock with me following as he had fouled plugs again. The question I couldn't answer , can you adjust the mixture on a fuel injected engine with out changin the injectors or reprogramming the computer? We are operating at 5000 to 6000 feet in altitude. The owner says it runs well below 3000 feet altitude. He's supposed to give me a call . This is out of my area of expertise. nevjb

 

[rickdb1boat]

Re: 115 merc 4 stroke

A fuel injected engine should compensate for altitude. Like a car, you don't do anything when you go from lower to higher elevations. It may run a bit better at lower elevations, but you should not have to change anything. There is no adjustment. Computer controlled!

 

[The Marine Doctor]

Re: 115 merc 4 stroke

Change his T-stat out and have him try it again.<br /><br />TMD

 

[backdraft]

Re: 115 merc 4 stroke

Thanks guys. The computer should compensate but apparently is not or cannot. The thermostat is a definite possibility. The dealer told him no to hotter plugs. I think that could be a cause as well. Appreciate your input. If he calls back, I'll give him your astute words of wisdom. nevjb