Outboard not accelerating

[Per]

I have zilch outboard mech experience but by the sounds of it, that is about to change

I have a 40 HP 2 stroke Suzuki on my dinghy.
Its been running really well, up until yesterday.

Started no problem but when advancing the throttle halfway through the powercurbe it "stalls" - not completely but like its not getting fuel/air in the proper mix.. and kinda flutters a little; retract the handle and she goes back to smooth running.

any ideas?

 

[LaBomba]

Sounds like a fouled plug(s) to me. I have had this happen on several occasions over the years. I always keep a spare set on board.

 

[Adelaide]

I have zilch outboard mech experience but by the sounds of it, that is about to change

I have a 40 HP 2 stroke Suzuki on my dinghy.
Its been running really well, up until yesterday.

Started no problem but when advancing the throttle halfway through the powercurbe it "stalls" - not completely but like its not getting fuel/air in the proper mix.. and kinda flutters a little; retract the handle and she goes back to smooth running.

any ideas?

Are you having to keep the choke open a touch? Have you tried that? Outboard motors have been having problems with ethanol blended fuel. try to find ethanol free gas and your problem may be corrected.

 

[bshillam]

Also if you have an inline fuel filter check that. A clogged fuel filter can also give a much lower throttle response. Replace the fuel filter.

 

[charles]

Check the throttle linkage, while you are at it. Had a nut come loose that advanced the spark so no acceleration. Easy fix, but must find it.

 

[mahal]

As suggested above, replace the spark plugs and fuel filter. If it is still not fixed, have the carbs serviced.

 

[Per]

very good, i highly appreciate everyones responses.
checking the plugs and fuel filter, hoping that is it..

 

[LaBomba]

very good, i highly appreciate everyones responses.
checking the plugs and fuel filter, hoping that is it..

Per, not to be a smart a$$ but change the plugs don't just check them. Lots of times they look just fine but are not firing. Good luck!

 

[bligh]

Im going to take a stab at it and say it is a fuel problem. clogged fuel filter, water in the gas tank, or dirty carburetor (if it is carbed). My experience with newer two strokes is that if the plugs are fouled , it would be difficult to start up.

 

[gwkiwi]

I just had my dingy with a 50hp Honda serviced last week, it was running bad above 1/2 throttle and the shop found a fuel filter full of water they also adjusted the carbs and today I was running at 35mph at 5600rpm.

 

[Searios]

Remove the bowl on the carburator, clean out the gunk at the bottom, blow out every nook and crannie of the bowl and the inside of the carb - you can use carburator cleaner or start help spray - something that contains alcohol and evaporates . That did it on mine this year.

 

[Dougcole]

More than likely a fuel related problem. Ethanol sucks. Period. Our tax dollars at work.

 

[Per]

update:
changed plugs, fuel lines and fuel filter. as a last resort added a fuel treatment..
no improvement.
next is carb cleaning, if still no good then i guess need a tune up.

thanks for all the advise everyone.

 

[RT Firefly]

Greetings,
Mr. P. Don't know much about Suzi outboards but assuming electronic ignition (rules out changing/adjusting points), changing the plugs and fuel filter is about all you have to do. I think the next logical step is, as suggested, carb cleaning. If THAT doesn't do it, could be, if so equipped...relays of some sort or reed valve damage. Maybe one of the coils (under the flywheel) is shorting out. I had a Merc where one of the magnets became detached from the flywheel.
Start with the simplest and cheapest first (carb).

 

[Iceberg]

Bad diaphram in fuel pump would do it.Abnormal gas shine on water from exhaust,easy fix if you have spare diaphram. Just another thought.

 

[David O]

Sounds like a clogged mid range carb jet. Disassemble the carb or at least remove the jets and soak everything in a clean can of carb cleaner (the kind with the basket) for 4 hours. Then spray with regular carb cleaner and reassemble.

You did not mention what happens at WOT. Sure sounds like the results of ethanol fuel sitting in the carb too long. Anything passed two weeks issues begin to develop.