1999 Honda 75hp 4stroke outboard is spitting and spuddering at higher RPMs. How do I fix this? I changed plugs

Question

I am thinking it could be the feul filter. I have changed plugs already and that did nothing. I ran SeaFoam through it and that did nothing. When I hit the throttle. it hesitates. spits and spudders but already goes after a while. It this a common problem?

Answer 1

Well, since this IS an outboard motor, not a car the most likely causes at the moment would be:

1. fuel starvation

2. bad fuel

3. the carburettor

1. To check the fuel filter..if it is a paper element, simply remove it from the plastic housing and run without it, or for the $5, just replace it anyway.

2. If you have not run the engine for 6mo or so it could be bad fule.. but i have never had issues with this...even with o/b fuel sitting for years.

3. Failing 1, 2, above, the problem seems similar to that of trying to rev a cold engine without enrichment from the choke and so points to a mixture problem or a dirty carb.

Though I am not familiar with the honda 75hp, carbs commonly have an idle s***w (presumably ok), then often there is one or two controls for mixture.

If you have one mixture control, try to make it richer (more fuel) if you have two, (one for idle, one for run) find out which is for idle (adjust and engine will become lumpy when rich, die when lean). Now adjust the other one :)... making the run mixture a little richer should help.

IF this fails then your carb jets need a good cleaning

Answer 2

if the car has sat for a while it could be bad gas. wich would also lead to a bad fuel filter and clogged injectors. although it could be clogged injectors or bad fuel filter without bad gas as well. my advice change the filter, and while you have the filter off. pump a little bit of glass into a jar or a glass and take a look at it. if its got particles floating in or a dark yellow its bad gas. also try to run an injector cleaner through it and see if that helps

Answer 3

Had the same problem with mine. changed the fuel filter fixed it.

Answer 4

IT sounds like you could have too much oil in it, or it was laid on its side and oil has gotten in the carb.  Either way:

drain the oil, and the gas, clean the carb and air dry it.  Then precisely measure the amount of oil and refill it.  Fill with gas.  Again check and/or change the plugs (they may be fouled).  That should pretty much fix your described problem.    GOOD LUCK