18HP NSF-18b Wont Start

Turbosl2

Cadet
Joined
Jun 23, 2017
Messages
28
Engine is a 2002, Does not start without starting fluid. Bought from my father in law and it seems it was like this since new. Its been used a few times and stored in my shed for many years with the carb drained. Last night tried to work on it.
Seems to be a fuel problem, even after it starts the engine is starving for fuel.
Pulled carb completely apart and cleaned, all ports seems to be free and clear. Fuel pump has flow when you pull it over. Enrichment circuit solonioid seems to work too...the only thing i see wrong is the rubber seal on the plunger is all torn and punky. Would this cause it to not start
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
If the solenoid and plunger works fine should not be an issue working with a faulty rubber seal. Just in case push plunger with finger till stops, release finger and check that plunger doesn't get stuck inside solenoid. If does so, clean plunger and solenoid interior.

Happy Boating
 

Turbosl2

Cadet
Joined
Jun 23, 2017
Messages
28
No issue with the solenoid. The plunger seal i am referring to is part 25 on the carb breakdown. It is the plunger that works off the throttle. Seems to drip fuel around that plunger when you go from idle to WOT. Wasnt sure if this is what is causing the no start issue. I checked the carb twice and nothing jumps out at me as plugged. There are many ports and passages that all seem clear. Any ideas?
 
Last edited:

km1125

Chief Petty Officer
Joined
Aug 10, 2016
Messages
515
This is the passage in the bottom of the float bowl. Mine had the same issue. This passage feeds the well that provides fuel to the choke enrichment and also to the idle fuel circuits. You need to remove the bowl and find the passage and work a wire through there to get it clean.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,559
No issue with the solenoid. The plunger seal i am referring to is part 25 on the carb breakdown. It is the plunger that works off the throttle. Seems to drip fuel around that plunger when you go from idle to WOT. Wasnt sure if this is what is causing the no start issue. I checked the carb twice and nothing jumps out at me as plugged. There are many ports and passages that all seem clear. Any ideas?

If you are referring to the boot on the accelerator pump rod, that should be replaced. More likely is the passage in the bottom of the bowl.
 

Turbosl2

Cadet
Joined
Jun 23, 2017
Messages
28
If you are referring to the boot on the accelerator pump rod, that should be replaced. More likely is the passage in the bottom of the bowl.

Yup that did it. Cleaned that out AGAIN with a wire as best i could and she started on first pull. Didnt run perfect but who knows it was sitting around for 7yrs, after warmed up it was smooth. Will check again at another cold start. Thanks for the help!
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,559
The boot for the accelerator pump is available. I have them in stock.
3R3033111MRUBBER BOOT
$5.67 plus postage.
It is complicated to change it; You have to pull most of the linkages apart.
 
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