motor using way too much fuel!!!

[Lostmygirltofish]

hey guys,
my motor is using way too much fuel. It is a 1988 johnson 120hp sea horse. Getting some white smoke when i start it up and periodicly when it is running. Just wondering if i should try some sea foam and changing out the spark plugs before getting ripped off by repair shop. Sent it in for the same thing before and they replaced the fuel pump. Any advice would be appriciated
thanks,

 

[tashasdaddy]

Re: motor using way too much fuel!!!

decarb never hurt anything. look for fuel leaks. that motor at wot will burn 12 gallons per hour.

 

[kenmyfam]

Re: motor using way too much fuel!!!

hey guys,
my motor is using way too much fuel. It is a 1988 johnson 120hp sea horse. Getting some white smoke when i start it up and periodicly when it is running. Just wondering if i should try some sea foam and changing out the spark plugs before getting ripped off by repair shop. Sent it in for the same thing before and they replaced the fuel pump. Any advice would be appriciated
thanks,

Are you sure it's not steam ???

 

[reeldutch]

Re: motor using way too much fuel!!!

TD is right these loopers guzzle gas.

how do the plugs look like?

i take my 20' mako on 10 mile trips and burn about 8 gallons.
most efficiant is when you have the timing fully advanced but not yet the trothle valves.

lean these bad boys out and they might blow up.

its not a 4stroke

 

[kenmyfam]

Re: motor using way too much fuel!!!

TD is right these loopers guzzle gas

Ball Park is 10% of the rated HP in GPH at WOT, for me it's around 14 GPH at WOT. (140HP)

 

[Lostmygirltofish]

Re: motor using way too much fuel!!!

I thank you guys for the advice. I'm sure it's not steam. I wish it burned that much in an hour. I put in the sea foam and ran it for a while and the rpm's at idle went down from 2,000 to 1,400 so hopefully this helps.

thanks again for the help.


Longhorns Gonna win it all!!!!!!!!!!!

 

[trendsetter240]

Re: motor using way too much fuel!!!

2000 RPM at idle? Even 1400 RPM at idle seems way high. You want that motor to idle around 650 to 700 rpm in the water. A little higher if you're running it on the water muffs.

Follow the procedure in your manual to set the idle to the recommended RPM.

 

[northernmerc]

Re: motor using way too much fuel!!!

Ball Park is 10% of the rated HP in GPH at WOT, for me it's around 14 GPH at WOT. (140HP)

Thanks for that reminder. Now I remember why we took the 4.3 L stern drive option on the Sea Ray. 14 gallons is good for a couple of days of hard skiing.

 

[kenmyfam]

Re: motor using way too much fuel!!!

Significantly less at cruising speeds though. We ski and tube on a lot less than the 10%

 

[reeldutch]

Re: motor using way too much fuel!!!

may be you have a loose main jet or hung up float.

 

[Lostmygirltofish]

Re: motor using way too much fuel!!!

Thanks for the advice.
Yeah I was running it on muffs. would it still need to be idleing at less rpms. it's a lot smother running after the sea foam.
Could the settings for the idle rpms be making it run at a higher rpm rate when you give some throttle?

Thanks again.

 

[tashasdaddy]

Re: motor using way too much fuel!!!

i would not worry about fuel usage, until you have the timing, idle speed and linc n sinc correct. get it all working correctly at the same time.