sputtering

[butch63255]

hello all,have a 1977 70hp evinrude just rebuilt the carbs took it out and first half of the day it ran like a race car,then started to sputter on and off like someone was pinching the gas line and letting go every other second.seemed to be ok at low rpm cruising but at fuel throttle it sputtered like it was starving for fuel......any ideas what might cause this? thank you for your help

 

[Daviet]

Re: sputtering

Sounds like something got into a high speed jet. Easy to remove and check. Are the fuel lines orginal? If so you need to replace them.

 

[butch63255]

Re: sputtering

fuel lines are brand new....took extra car when cleaning carbs to not get them dirty(of course not positive that didnt happen)someone mentioned maybe fuel filter?pump might be dirty or clogged? just got this boat a few weeks back and have no idea when that was last changed and it was sitting for several years could this affect something?

 

[kenmyfam]

Re: sputtering

Check fuel system for cleanliness and while you are at it check the fuel output of your pump.

 

[jonesg]

Re: sputtering

When you changed the lines did you flush the tank?
its leaning out due to blocked fuel flow when it does that.
Kinda like pinching the fuel line, also check the tank pickup.

New to you, sitting for some time, go through everything.
Get the factory manual if you don't have it, seloc doesn't cut it.
www.outboardbooks.com

 

[butch63255]

Re: sputtering

thanks for all the advice i will dig into it and see if i cant get her fixed up

 

[jonesg]

Re: sputtering

Top to bottom,
change the gear oil , new seals on the drain screws after filling it.
Remove prop, check prop shaft for fishing line, it will cut the seal if left.
Regrease the prop shaft and use new stainless cotter pin.
If you don't know the history change the water pump, every 2 yrs anyway.

And thats just to catch up.