2001 25hp Nissan NS25C3 - Trouble Starting

[NissanOutboard]

Hi Everyone,

I recently got a steal on a boat, trailer, and outboard -- the outboard is a 2001 25hp Nissan NS25C3.

I am having issues starting the motor -- it takes 5 - 20 pulls to get it started. I am using the manual starting instructions. Choke until you hear combustion and then turn the choke off and start the engine.

Once the engine starts, it seems to be running pretty well for a 22 year old motor.

Since getting the outboard I have:
Changed spark plugs - NGK BR7HS - 10
Changed impeller
Changed Fuel and Ran Seafoam Marine through it

This boat set up will be used to Duck hunt next season so I need the starting to be reliable.

I would love to know why you all think it is giving me such a hard time to get started.

I am thinking I need to pull the carb off and clean/rebuild, check the fuel line, and maybe test the compression?

Please let me know your thoughts.

 

[presleymarkw]

Hi Everyone,

I recently got a steal on a boat, trailer, and outboard -- the outboard is a 2001 25hp Nissan NS25C3.

I am having issues starting the motor -- it takes 5 - 20 pulls to get it started. I am using the manual starting instructions. Choke until you hear combustion and then turn the choke off and start the engine.

Once the engine starts, it seems to be running pretty well for a 22 year old motor.

Since getting the outboard I have:
Changed spark plugs - NGK BR7HS - 10
Changed impeller
Changed Fuel and Ran Seafoam Marine through it

This boat set up will be used to Duck hunt next season so I need the starting to be reliable.

I would love to know why you all think it is giving me such a hard time to get started.

I am thinking I need to pull the carb off and clean/rebuild, check the fuel line, and maybe test the compression?

Please let me know your thoughts.

It's always good to test the compression when you get a used engine. If you are at elevation remember to adjust for that or your compression reading could seem low. Just gives you some base confidence. And ya sounds like a carb cleaning. I looked at the carb diagram and I dont see any external jets you can access without taking it apart. On my Honda there is a pilot jet I can unscrew externally when it gives me starting issues like that. I run a piece of wire in the holes and it goes from 5-20 to 2 every time.

I also have to really respect start up steps to get 2 pulls every time, for my Honda I have to pump the bulb and set the throttle to the start position and choke it. So make sure you are catching all the steps.

Another thing to check that helped me allot is to watching the choke linkage and make sure when its choked the choke arm is being moved to its full extension. Mine wasn't quite and would cause more pulls.

 

[dwco5051]

I have pretty much have that same motor. One of the best running ones I have ever owned. The only thing is that carb must be squeaky clean as the passages are small. You should be able to download the basic repair manual from Tohatsu's website to show what all passages the carb has. Magic in a can will not do it, take it apart and clean it like a fine watch. Of course check compression, spark and timing. Those little motors should be two pull cold and one warm starters. Also what we call a needle for the low speed jet the English translation from Japanese in the manual they call a pin. Took me a couple minutes and the diagrams until I figured that out.

 

[NissanOutboard]

Here is an update -- I changed the fuel filter, cleaned the carb, and checked that fuel is flowing well from the tank to the filter. I guess the fuel pump is the next to be replaced.

The motor is still giving me starting issues and seems to be running lean. Any chance it could be an issue with the air/fuel mixture screw? Maybe an issue with the plugs? They are new as of a few days ago.

 

[presleymarkw]

Here is an update -- I changed the fuel filter, cleaned the carb, and checked that fuel is flowing well from the tank to the filter. I guess the fuel pump is the next to be replaced.

The motor is still giving me starting issues and seems to be running lean. Any chance it could be an issue with the air/fuel mixture screw? Maybe an issue with the plugs? They are new as of a few days ago.

I don't think fuel pump is going to be your starting issue. Generally pumping your bulb fills the carb. When you pump your bulb does it get hard? If not your float adjust may be an issue or the needle isn't seating right.

If you spray a little fuel in the throat does it start easier? Don't use starting fluid.

When you cleaned the carb, did you just spray cleaner on it or did you dip it? Use compressed air and or run a wire through every little pin hole in every jet? I use a piece of guitar string.

I have cleaned the carb, only to finally take it to a mechanic, be without my boat for 6 weeks and to find he just cleaned it better for $250.

 

[presleymarkw]

I don't think fuel pump is going to be your starting issue, but they are also not expensive and easy to change. Generally pumping your bulb fills the carb. When you pump your bulb does it get hard? If not your float adjust may be an issue or the needle isn't seating right.

If you spray a little fuel in the throat does it start easier? Don't use starting fluid.

When you cleaned the carb, did you just spray cleaner on it or did you dip it? Use compressed air and or run a wire through every little pin hole in every jet? I use a piece of guitar string. For my snowblower the carb was only $70 I just bought a new one.

I have cleaned the carb, only to finally take it to a mechanic, be without my boat for 6 weeks and to find he just cleaned it better for $250.

 

[NissanOutboard]

I don't think fuel pump is going to be your starting issue. Generally pumping your bulb fills the carb. When you pump your bulb does it get hard? If not your float adjust may be an issue or the needle isn't seating right.

If you spray a little fuel in the throat does it start easier? Don't use starting fluid.

When you cleaned the carb, did you just spray cleaner on it or did you dip it? Use compressed air and or run a wire through every little pin hole in every jet? I use a piece of guitar string.

I have cleaned the carb, only to finally take it to a mechanic, be without my boat for 6 weeks and to find he just cleaned it better for $250.

Yes pumping the bulb does get the bulb hard. The float/adjustment could be the issue. How can I check to make sure I am getting the proper adjustment/seeing if the needle is seating right.

I tore the carb off again and have stripped it down. Cleaned with spray cleaner and now I am letting it soak. I used a guitar string to make sure all jets are clear.

Also I replaced the fuel pump just to make sure that’s not the issue. So now I’m running new plugs, fuel pump, fuel filter, new gas w/ sea foam, and the cleaned carb.

Going to toss the carb back on tomorrow or late today and give it a spin.

 

[NissanOutboard]

Finished cleaning up the carb today -- that thing is squeaky clean. Raining here today I'll put it back on tomorrow and give it a go.

Yesterday I checked the spark plugs that I installed 10 days ago and I noticed they are already fouling.

I have attached some pictures -- any ideas why they are already fouling? This seems to me it could be a weak spark?

 

[dwco5051]

Running rich or wrong gasoline/oil mix.

 

[MattFL]

That "optimal" plug is not representative of an actual "optimal" plug from an old school premix 2-stroke boat motor. That looks like a plug from a 4-stroke, or a 2-stroke that was run extremely hard.

 

[NissanOutboard]

Fuel to Oil mix is 50:1

I’m guessing maybe it’s running rich. Where I get confused is on another thread posted by me the gents think I have a lean sneeze going on.

If anyone can provide a bit of clarity that would help. I hesitate to think I’m running lean especially after checking the plugs.

 

[presleymarkw]

Yes pumping the bulb does get the bulb hard. The float/adjustment could be the issue. How can I check to make sure I am getting the proper adjustment/seeing if the needle is seating right.

If the bulb gets hard after a few pumps it means the needle allowed fuel into the bowl and stopped letting it in when the float leveled out and the needle drops into the seat. So if your bulb doesn't ever get hard it means the float adjust may not be right or some other problem with the needle seating. This could lead to a flooded condition and make it harder to start.

 

[NissanOutboard]

Alright gents - I have an update

I put the carb back on and tried to pull start it again. It will start a tad bit easier -- 5-10 well timed and primed pulls. I also swapped the fuel hose and bulb for a new higher quality set.

That wasn't good enough for me. I noticed the engine had an electric starter that was previously installed. I did some testing and realized that it worked fine. The solenoid wiring was all messed up though and there was no switch previously installed.

I fixed the solenoid wiring and attached battery cables. I installed an ignition button and wired it properly to the solenoid. I bought a new marine cranking battery and hooked it up.

This new set up gets the motor started easily. The smile on my face when it cranked up without a hitch was priceless. Now I just need to fine tune the motor a bit to have it running optimal.

Thanks for the help guys.

 

[dwco5051]

Alright gents - I have an update

I put the carb back on and tried to pull start it again. It will start a tad bit easier -- 5-10 well timed and primed pulls. I also swapped the fuel hose and bulb for a new higher quality set.

That wasn't good enough for me. I noticed the engine had an electric starter that was previously installed. I did some testing and realized that it worked fine. The solenoid wiring was all messed up though and there was no switch previously installed.

I fixed the solenoid wiring and attached battery cables. I installed an ignition button and wired it properly to the solenoid. I bought a new marine cranking battery and hooked it up.

This new set up gets the motor started easily. The smile on my face when it cranked up without a hitch was priceless. Now I just need to fine tune the motor a bit to have it running optimal.

Thanks for the help guys.

Just love a story with a happy ending!!!