Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

[scjakester]

Hello folks,

I just bought a used (2002) Carolina Skiff J16 with a small 25hp 2002 Nissan (Tiller/Carbureted/electric start). The model number is NSF25A. It looks like new, but the previous owner said it was a "very cold natured" motor. I didn't find that in any of the reviews I looked at researching the motor so I am kinda wondering if something may not be quite right with it. It took me a while (60+ seconds of turning it over) to get it to even hit and sputter this afternoon. He said after you get it running for a few minutes it does great, but its crabby when you first get going with it. He mentioned the Ethenol fuel content in his area gums up the carbs pretty bad and he had to clean them fairly often, which he just did last week. I can get fuel here with no Ethenol added, so that problem should go away, assuming it really was an Ethenol problem.

Is this really just a "cold natured" motor or should I take it to the Tohatsu dealer near my house and get it diagnosed?

Thanks in advance for any responses.

Jake
South Carolina

 

[sgrem]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

I had a carburated Nissan 70 hp 1998 model. I squeezed the primer bulb.....neutral throttle up just a bit......choke and hit the key. every time it sputters choke again...thats what worked for mine.

 

[pvanv]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

60 seconds of cranking is not normal. The 25A should start on 1 or 2 pulls of the recoil. That's about 5 seconds of electric cranking.

Ethanol does not gum up carbs. Leaving gas in the carbs to evaporate... and leave a residue... is what does that. You must idle the carbs out at the end of each and every day to prevent that.

Sounds like the carbs are delivering a too-lean mixture. Could be inadequate choke, poor fuel delivery from the pump, leaky intake manifold gasket, or... more likely that you need a proper carb cleaning -- disassembly, 4-hour bath in carb dip, blow out with generic carb spray, and careful reassembly. Then the carbs need to be synchronized, using a multi-carb manometer.

I would suggest a visit to the local dealer. Or you could learn to do that task yourself, if you have average mechanical skills, attention to detail, and can borrow a manometer and nipples to attach it to the intake manifold.

 

[Sea Rider]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

I would agree on cold motor behaviours, when hot starts at 5 cm rope pull, when cooled down after a long stop, must move throttle a bit, if doesn't start at 2 pulls max, pull choke and when starting close choke inmediately. That formula works for me. There's a temp start procedure, will depend on your exterior working temperature, it's applied to 2 strokes 25/30 models, don't know if could be applied to 4 strokes versions ?

Happy Boating

 

[TOHATSU GURU]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

Hello folks,

I just bought a used (2002) Carolina Skiff J16 with a small 25hp 2002 Nissan (Tiller/Carbureted/electric start). The model number is NSF25A. It looks like new, but the previous owner said it was a "very cold natured" motor. I didn't find that in any of the reviews I looked at researching the motor so I am kinda wondering if something may not be quite right with it. It took me a while (60+ seconds of turning it over) to get it to even hit and sputter this afternoon. He said after you get it running for a few minutes it does great, but its crabby when you first get going with it. He mentioned the Ethenol fuel content in his area gums up the carbs pretty bad and he had to clean them fairly often, which he just did last week. I can get fuel here with no Ethenol added, so that problem should go away, assuming it really was an Ethenol problem.

Is this really just a "cold natured" motor or should I take it to the Tohatsu dealer near my house and get it diagnosed?

Thanks in advance for any responses.

Jake
South Carolina

There is something wrong with it or something wrong with the technique being used to start it. They are not "cold natured" and should start within a few seconds as Paul said earlier.

 

[SaabFAN]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

I had a 2004 Tohatsu 5hp 2-Stroke, which had problems with cold start too: Starting it in really cold weather, i had to pull the choke completely out (it had 3 positions: Open, 1/2 choked, fully choked) and pull one or two times to get an ignition. After the first ignition, i had to push in the choke to the 1/2 choked-position, or it would die immediately.
In normal weather (air-temp 16?C or higher), it didn't start with the choke completely pulled. Maybe this is your problem too: It is choked too much, so that the mixture is way too rich to allow combustion.
If your engine has only full Choke or no Choke, it might be worth the try to do one or two pulls with Full Choke and then push it in before giving it the third pull.

If this isn't helping, maybe a carb-clean does the trick.

 

[scjakester]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

Thanks for all the replies.

I have no experience with this engine. My last 2 boats (with their 5 different motors!) were a series of gradually worsening horror stories and I am really gun-shy on boats now. After 2 years of solid memory suppressive therapy, I gave in and bought another boat. This one is everything my last 2 boats were not, it's small enough for one man to handle, its a tiller handle motor so it has fewer movable (ie, breakable) parts, it is a 4 stroke, it has a good reputation, it's more modern, etc....

When I bought it last week it was running on muffs and sounded really smooth. I bought it and towed it home and just parked it behind the house. I've been so busy with work I haven't really had time to even try to start it back up. I think (hope/pray) it's going to be a good motor for me, I just want to make sure I won't get stuck out there on the lake (yet again) if I can at all avoid it!

I think it might have had something to do with the kill switch not being completely engaged. When I pulled it out and reset it, it hit and sputtered and I shut it back off because it was out of the water. We'll try it again tomorrow either way. A friend of mine is a professional mechanic (Toyota Dealership) and he's coming over tomorrow morning to help me with the simple stuff. We're going to replace the plugs, all the fluids, the water pump, double check all the electrical connections, etc. He said he really wasn't comfortable synchronizing the carbs, so if the plugs and a good old fashioned cleaning doesn't do the trick, I'm going to drop it off at the Nissan-Tohatsu dealer here in Lexington, SC on Monday and get them to take look at it one day next week.

 

[scjakester]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

I just heard back from the Nissan-Tohatsu Service Center. He said the compression and spark are perfect, but my carbs are monkeyed-up. The spark plugs show that only 1 cylinder is burning any fuel mixture. I can get my brain around simple stuff (fluids, plugs, etc) but I am not a mechanic. Does this sound reasonable to you guys? The technician said only one cylinder is seeing even a nominal amount of combustible fuel, the other two remain dry.

The tech said if he sprays some kind of mixture into the carbs (one-at-a-time) the motor will run on that cylinder, then stop when he stops. He thinks the carbs are starving the engine and keeping it from running. His recommendation is to remove them, clean them in some kind of sonic bath gadget and check to see if any of them need carb kits.

He said 99/100 you don't need to rekit the carbs in those motors, just use the sonic thing. They are charging me 3.5 hours of labor @$85.00 per hour (plus parts if they need to rekit). The plan is to remove, disassemble, bath, and possibly rekit them. The labor charge also includes resynchronizing them and taking the boat for a test run.

Don't get me wrong, I'm not balking at this, I just wanted to see if it sounds like a reasonable diagnosis/rate to you guys?

-Jake
South Carolina

 

[WHITENOISE]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

I'm here in Florence and unfortunately that sounds about right. Labor is high but its cheaper than the chiropractor after paddling back home. The sonic thing really does a good job cleaning the gunk. Sounds to me like a pretty fair deal considering it includes resynchronizing.

 

[sschefer]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

Heck of a deal Jake. I'd be on it in a flash. My guess is that the prior owner didn't want to pay to have it done right so he did it himself and, well, you know the rest of the story..

 

[TOHATSU GURU]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

It does sound reasonable on all accounts.

 

[scjakester]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

Man... that's some funny stuff!

...labor is high but its cheaper than the chiropractor after paddling back home.

Ok, thanks a lot folks, that makes me feel better about it. I think they are pretty smart on those things. He (Weed's Nissan-Tohatsu Marine) has been in business for a pretty good while and they have all kinds of Nissan-Tohatsu & Mercury training certificates hanging up so it looks like they keep up with that product line pretty well -- it will done by Friday.

Who knows, if everything goes right I might be paddling back home by Saturday. Ha!

Thanks again.

-Jake
South Carolina

 

[pvanv]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

Yes, that sounds reasonable. Should have you motoring soon. Then, in the future, keep in mind that you need to operate the motor correctly. That means proper shutdown, which means running the carbs out at the end of the day (unless you know for 100% certain that you will be using the motor the next day). That way, you won't get the varnish accumulation caused by leftover fuel evaporating out of the carbs.

 

[scjakester]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

Hey folks, I got my boat back Friday but didn't get time to put it in the water until tonight. It started like a new boat! That sonic bath thing in amazing, the outside of the carbs look like they just came out off the assembly line, no amount of Napa carb cleaner could have done that.

Started like a new one, 2nd pull, my nephew ran it out in the cove for a few minutes, it seemed nice and strong. Brought it back to the dock to adjust the motor down a little. Ran it again in the cove for maybe 2 minutes and it stalled out on him. Pulled the cover off and there was fuel pouring out from the bottom of the carbs. It was getting dark so I couldn't tell where it was coming from. Called the Nissan-Tohatsu dealer and he said to drop it off on the way to work and it will be the first thing on tomorrow agenda.

Question: I've never owned a boat with external fuel tank before, and while loading it onto the trailer I noticed a breather screw molded into the fuel tank's lid. I twisted it open and there was a vacuum in there. I could hear it sucking in a lot of air and the sides of the tank let out just a little bit. Might be a really dumb question, but would that breather screw not being open have anything to do with the fuel dripping out of the carbs?

-Jake
South Carolina

 

[levi_tsk]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

not likely but it DOES need to be open though (could be a hose clamp loose or something that wasnt put back on in the reasembly process ) i will add also that my tohatsu wasnt cold natured UNLESS the battery wasnt topped completely off so id keep it trickle charging when its not in use

 

[pvanv]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

The fuel should not be running out like that. Best to have the shop review their work, as levi said. Also a good idea to read and understand the owner's manual, available at http://www.nissanmarine.com/tech_talk/pdf_files/Nis25_30_4str.pdf You do need the tank vent open in order to get gas out of it to run the motor.

 

[WHITENOISE]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

It is possible that the engine stalled from a lack of fuel because of the venting issue. And as the motor stalled it sneezed or blewback a little fuel out the front of the carbs. I believe that would be a very small amount of fuel.

 

[SaabFAN]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

Almost every Outboard i have owned so far leaked a little bit of fuel out of the Carb. Especially when i tilted them up, or put them on the ground for storage.
The dark color indicates, that the leaking fuel contains high quantities of oil (maybe with combustion-byproducts), so its possible, that the vaccum in the tank (and in the Carb as well) sucked Oil out of the engines Crankcase.
Worst case: You damaged the diaphragm in the fuel-pump, which is easy to replace, or sucked a gasket out of place. Both no drama and easy to repair.

 

[scjakester]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

The mechanic took it for a 30 minute ride and then put it on the muffs for a while. Called and said "there is nothing wrong with it" hopefully it was just the vent not being open, or maybe a Higher Power just doesn't want me to ever be comfortable on a boat... I thought smaller, 4 stroke, more modern, etc would stop the craziness. I've ran the boat 6 minutes in the 5 weeks I've owned it. One of those 5 weeks it sat on the ramp inoperable, then 4 weeks at the shop, 2 trips to the mechanic, and after the 6 minute run, I watched my nephew paddle it back to the dock. I love to fish, but I gotta tell you, I really hate boat motors. I just don't get it.

 

[pvanv]

Re: Carburated Nissan-Tohatsu Outboards "Cold Natured" motors?

The modern 4-strokes of all brands are quieter, cleaner, more efficient, and more reliable than some of the motors of 40 years ago. But they are a completely different animal, and if you've never owned or operated one before, it is important to become familiar with your motor. Definitely RTFM, available for download from the Tohatsu and Nissan Marine websites (as I mentioned a couple of posts ago). You could also ask your dealer for any tips specific to your motor, as well as general 4-stroke OB operation techniques.

Run fresh gas, never more than 30 days old.
Run a water-separating fuel filter on any motor that has an external fuel tank.
Always run the carbs dry at the end of the day.
Open the tank vent to run, close when storing overnight or longer.
Run non-synthetic 10w30 oil, NMMA rated FC-W.
Fill 1/2 to 3/4 on the dipstick. Never overfill, not even a drop.
Avoid extensive idling.

Enjoy your fishing!