Suzuki 140DF losing rpms

[islandhopper]

I've read a lot of old post so maybe someone has an answer. Just purchased boat with 140df. Ran fine for a few weeks then I noticed that I couldn't get over 4200 rpms. (Used to do 4600) Days later ---4000 if lucky. Now it tops out at about 3200 and 3000 with a few people on board.
Put new racor so I can see fuel/water, new plugs, new fuel filter, 2 new batteries, new gas ...... same thing.

It would start out --run it to 4200 then it would back down. Won't do that now.

Think it's the fuel pump but really don't want to start guessing.

thanks

 

[JUSTINTIME]

Re: Suzuki 140DF losing rpms

what year?

 

[islandhopper]

Re: Suzuki 140DF losing rpms

Sorry ------2003 Suzuki 140df 4 stroke
I know there is one fuel pump that is easily accessable ---been told that there is another one and that it has a screen/filter that could be the problem.
Just ran it again ---same thing 3400 is all I can get --with a little (very little) sputtering. @ 2600 ist's like nothing is wrong.

 

[JUSTINTIME]

Re: Suzuki 140DF losing rpms

sounds like the vst strainer
drain and see if there is water

 

[islandhopper]

Re: Suzuki 140DF losing rpms

sounds like the vst strainer
drain and see if there is water

I couldn't get to the vst so I checked the plugs agina and noticed that 2 of them didn't have any black on them. So I checked the injectors and the corresponding injectors had some black stuff in there.

Cleaned those and It ran great for about an hour. Cleaned them again and running good.

Have new ones on the way ----hopefully that'll fix it.

 

[reeldutch]

Re: Suzuki 140DF losing rpms

if you have black crud in your injectors its time to replace the high presure fuel filter or your new injectors will get the same crud in it.

there are places you can get the injectors cleaned.

 

[islandhopper]

Re: Suzuki 140DF losing rpms

Yea I was thinking that ---I don't want to ruin the new ones.

Thanks