92 Nissan 90 not staying running

Stvpkr

Cadet
Joined
Feb 28, 2016
Messages
11
I bought this boat in March and when I met the person they were not home when I arrived. So after about 30 mins he showed up and went to start it for me and it took a couple turns but fired up. It ran a bit rough at first he said was cause it was first start of season. Anyway after a min it started it run fine. He did put it in gear and ran it if I remember correctly and ran the motor for a good 5 mins. So I tow it home and it has sat since March. We decide to go to lake today and no go, so we come home. I take the cover off and check plugs they don't seem to fire that great, so I go get new ones. Still same thing motor will not start. I see what looks like a rod coming from an electric box that I assume is the choke and pull it a bit and it fires up. But will only stay running while holding the rod about half way. It does sputter a bit here and there so I just feather the throttle from the carb to keep it going. I ran it this way for 10 mins or so with no luck of it staying running. My questions are bad gas from sitting and need to run it longer to work it out? And why was the motor not activating the choke since it was a cold start? Or should I be looking at something else? I was going to take the big cover off the carbs but could not get to the bottom 2 bolts without a swivel adapter to the socket which I could not find and there was no way to get a wrench in there.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,579
What method did you use to check the plugs? Did you set the gap on the new plugs? If so, at what gap? You are aware that the NS90A has push-to-choke, right? The choke is not automatic. DL your owners manual from nissanmarine.com or tohatsu.com. Today's US fuel goes bad after about 30 days. Really bad after a winter.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Assume it's a 2 stroke OB, if sitting for long time periods with left over fuel on carbs will need to clean them to a immaculate clean state to work as intended. Fuel evaporates and oil residues begins doing naughty things inside carbs. Plugs must be gapped tight to 1.0 mm.

Happy Boating
 

Stvpkr

Cadet
Joined
Feb 28, 2016
Messages
11
The only thing I seen was the high speed lever didn't notice a choke but il look again tonight. To check plugs I just pulled one and put it on the block wile turning it over.
 
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Stvpkr

Cadet
Joined
Feb 28, 2016
Messages
11
Ok so I read the manual and it says to leave the high speed lever down to start which makes no since to me. Any thing iv had in the past on a cold start you would turn the speed up a bit on a cold start then turn the lever off after it is warmed up. So I guess il give that a try this weekend when I get it back out. So in the mean time is there any kind of additive I could get to add to the fuel to mabey help clear up the carbs? If so should I keep running it at home withe the hose on the motor or get it out on the lake and try to get it started then open it up out there?
 

pvanv

Admiral
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Apr 20, 2008
Messages
6,579
You need to verify that you are looking at the correct manual. NS90A. re-read that section in the manual about starting again. You will want the neutral warm-up lever activated for either a cold or warm start. You will also want to push in on the key to choke when cold. Old bad gas is old bad gas and cannot be revived. Running on the hose is never as good as running in the water. Many water pumps have been destroyed by running on the hose.
 

Stvpkr

Cadet
Joined
Feb 28, 2016
Messages
11
I was reading the wrong one and reason for not knowing about the choke someone mounted my controlles so the key is in the bottom. Thanks for the info.
 

Stvpkr

Cadet
Joined
Feb 28, 2016
Messages
11
Well it will only stay running while the choke is held in. What are my options to fixing this?
 

Stvpkr

Cadet
Joined
Feb 28, 2016
Messages
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I can do that just afraid of them being out of sync when I get done or a screw adjustment not in the right place. Mostly wondering if I should take it to a shop or if it is doable at home with normal tools.
 
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Stvpkr

Cadet
Joined
Feb 28, 2016
Messages
11
Well took carbs off and carbs 1 and 3 the jet in the bowl was gunked over cleaned all the carbs and replaced. Boat is now running pretty good thanks for the help I wasn't afraid to take carbs off and clean them it was getting them out of sync but it wasn't an issue.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
For peace of mind, with the measuring protruding end part of a vernier tool can measure each carb mixture screw height individually and put them back to where they were originally adjusted prior being removed. The only way to adjust properly multicarbs is having a trained ear along knowledge or using an electronic vacuum tester which is the best method possible. Run carb dry after each outing..

Happy Boating
 
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