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Nissan 3.5A 4 stroke won't idle

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sailndoug

New member
Just did a rebuild on the carb and put a new spark plug in but it won't run unless the choke is at half way on. When I take the choke all the way off, it dies right away. Any ideas? Thanks!
 
pvanv said:
Revisit the carb. What method did you use to clean it as part of the rebuild?
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Thanks for the reply. I installed the new parts and put it back together. Nothing more. The old needle was pretty gummed up. It runs OK with some choke which is much better than it was. It didn't start at all before. Did I miss something?
 
You didn't dissolve the varnish deposits from the tiny passages in the carb body.

Pull the carb. Do a complete disassembly, including jet and the emulsion tube nozzle. Do a 4-hour room-temperature soak of all non-rubber bits in real carb dip (available in 1-gal. cans at the auto parts house), followed by a liberal and aggressive blow-out of all passages using generic carb spray. Use a whole can. Then reassemble, paying particular attention to float height. Then you should be OK.

If you pulled the EPA-mandated block-off plug from the idle mixture (pilot) screw (and disturbed that setting), you will end up needing to readjust that setting. That will require a precision shop tach, a good ear, and patience. Figure a good start is about 2 turns out from lightly seated.

In the future, any time the motor will not be run for over a week, be sure to either idle the carb dry, or drain it, to reduce the varnishing that is a result of the poor-quality US fuels typically in use today.
 
pvanv said:
You didn't dissolve the varnish deposits from the tiny passages in the carb body.

Pull the carb. Do a complete disassembly, including jet and the emulsion tube nozzle. Do a 4-hour room-temperature soak of all non-rubber bits in real carb dip (available in 1-gal. cans at the auto parts house), followed by a liberal and aggressive blow-out of all passages using generic carb spray. Use a whole can. Then reassemble, paying particular attention to float height. Then you should be OK.

If you pulled the EPA-mandated block-off plug from the idle mixture (pilot) screw (and disturbed that setting), you will end up needing to readjust that setting. That will require a precision shop tach, a good ear, and patience. Figure a good start is about 2 turns out from lightly seated.

In the future, any time the motor will not be run for over a week, be sure to either idle the carb dry, or drain it, to reduce the varnishing that is a result of the poor-quality US fuels typically in use today.
Click to expand...
Thanks Paul. I will do it as you suggest. You gave more info than the service manual! I did not mess with the pilot screw so I'm hoping that is fine. I'll let you know.
 
sailndoug said:
Thanks Paul. I will do it as you suggest. You gave more info than the service manual! I did not mess with the pilot screw so I'm hoping that is fine. I'll let you know.
Click to expand...
Finally got some time to do the job. That was the ticket. Thank you Paul! I now know not to trust the book, it was a little lean on info like this.
 
When I purchased my 2008 3.5 h.p. the dealer ran it for me using non-alchohol gasoline. He said it would run O.K. with alchohol gas - BUT! I ran it with alchohol gas and it ran rough. Use non-alchohol and it runs much better.
 
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