Association Forum - Issues with Nissan/Tohatsu 9.8

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

General Sailing Forum

Issues with Nissan/Tohatsu 9.8

New Topic

Topic Locked

Printer Friendly

Author

Topic

Ben
Master Marine Consultant

Member Avatar

USA
1234 Posts

Initially Posted - 06/28/2010 : 05:47:11

Hi all,

After the last Wednesday Night race, the engine started to run very rough on the way back to the dock. It would sound like it was choking, and trying to stall out every few moments. I increased the throttle a bit to avoid stalling, and we subsequently did NOT stall out, but a couple times it seemed like we almost did.

About five minutes after the symptoms began, the engine started running smoothly again. I kept the engined throttled up a small bit until we were at the dock because I was afraid of stalling if I put the throttle back to idle.

Could this have been water in the gas tank? I took the gas tank home, emptied it and refilled it with fresh gas.

Then Saturday I took it back to the boat and ran the engine for a while. It started fine, and ran fine at a throttle setting just slightly above idle-speed; but when I decreased the throttle to idle speed the engine would slowly sputter and stall if I didn't increase the throttle again.

When the engine WOULD stall, or when I manually stopped the engine, it would be more difficult to get re-started. I would have to have the choke out a bit and massage the choke while holding the Start button, and only after the engine really got going could I put the choke back in.

I've never had difficulty in starting the engine, and I've never had problems with the engine at all in fact. it is a 2006 model, and has always run excellently.

Any ideas?

Ben
Beneteau 361
Viking Kitty
Columbus, Ohio

Edited by - on

John Russell
Master Marine Consultant

Members Avatar

USA
3444 Posts

Response Posted - 06/28/2010 : 06:01:53

Sure sounds like a fuel issue. Maybe a new fuel filter? A blast of carburetor cleaner down the throat of the carburetor? Does it improve if you pull out the choke a bit at low throttle? Need new spark plugs?

Edited by - on

Don B
Captain

Members Avatar

USA
317 Posts

Response Posted - 06/28/2010 : 08:13:35

Possibly air getting into the fuel line?? Many fuel lines are made cheaply..from the bulb to the clamps. Try a new fuel line..even if that's not the problem, it's always good to have a back up.

Edited by - on

jbkayaker
Captain

Members Avatar

USA
299 Posts

Response Posted - 06/28/2010 : 08:24:18

Sure sounds like a fuel contamination problem to me. If you are using fuel that contains ethanol it may have absorbed water. First try replacing the fuel with fresh ethanol free gas. If you can't find a local source for gas not contaminated by ethanol try adding the prescribed amount of Sta-Bil red label to fresh fuel from a high volume gas station.

Edited by - on

Dave5041
Former Mainsheet Editor

Members Avatar

USA
3758 Posts

Response Posted - 06/28/2010 : 10:17:26

You have clean fuel, so I would add a little carb cleaner to the fuel and spray carb/choke cleaner down the intake with the engine running and probably change plugs. These are cheap approaches that may solve your problem. If that doesn't do it, then I would move on to more involved processes. It could be idle speed or idle air settings, or dirty jet. Air in the fuel line or a dirty fuel filter usually gets worse as the load increases, and water usually will commonly cause rough running or stalling throughout the rpm range. If the carb bowl is accessible, it is easily removed and cleaned and allows you to blow out the jets if you have compressed air..

Edited by - on

Ben
Master Marine Consultant

Members Avatar

USA
1234 Posts

Response Posted - 06/28/2010 : 17:21:59

Thanks for all the tips, folks! :-)

Edited by - on

OLarryR
Master Marine Consultant

Members Avatar

USA
3475 Posts

Response Posted - 06/29/2010 : 03:54:40

I have had issues with the fuel connector from the fuel line to the outboard...and not just once...a few times. I suspect this happens more frequently to me because I go on many short sails throughout the year, probably more than most and that adds up to more frequent connecting and disconnecting of the connector from the outboard.

The first time I had a problem with the connector, it was stealthy - No real symptoms other than hard starting or cutting out of the outboard. It turned out to be a microscopic hairline crack on the face of the connector adjacent to the small o-ring. Replacing the connector resolved the issue. The second time, the issue was more obvious. Squeezing the bulb, I could smell gas and see the gas tint in the water. Replaced the connector and issue resolved. The last time...well this is a design issue and beef I have with some of the replacement connectors available. The original OEM HOnda connector had a little spring lever for connecting/disconnecting the connector. The Mueller replacement connector does not use a spring lever. They use a metal channel that bends when you press on top of it and that simulates the spring action. The edges of the slot in the metal channel is what latches the connector to the outboard but after subsequent frequent connector use, the channel flex either relaxes or gets bent a bit and sometimes the edges of the slot do not hold the connector firmly to the outboard connection. I have had at least 2-3 instances of the connector disengaging from the outboard while the outboard was running. Twice this has happened right inside the marina. I had to quickly grab the dangling fuel line, bend the metal channel amnd reconnect the fuel line to the outboard. Sounds worse than it was to do - Took perhaps 10-15 seconds to accomplish and then outboard restarted immediately. But after looking for a replacement connector and thought from the catalog I was getting one with the spring lever, turned out I bought two morw with the same channel type spring mechanism.

Anyway, if your problem is a hairline crack in the fuel connector, then problem resolve is easy enough. But likely one of the other suggestions mentioned by the others will help resolve your issue.

Edited by - OLarryR on 06/29/2010 03:58:42

britinusa
Web Editor

Members Avatar

USA
5404 Posts

Response Posted - 06/29/2010 : 04:51:45

We had an issue with water in the fuel line a while back. When I depressed the disconnected fuel connector with pressure in the pump bulb, dirty muddy fuel squirted out. The tank was clean and unpolluted, but the line had been left with fuel in it during a few storms, so I'm guessing that the ethanol sucked up some of the atmospheric water. I was able to quickly strip down the carb and clean it out with a can of starter (high octane) fluid that I had on hand. No more problems since then.

I now routinely flush the engine after every trip and disconnect the fuel line at the tank and leave the engine running until it empties the line, then I stow the line in the garage.

Let us know how things work out.

Paul

Edited by - on

DaveR
Master Marine Consultant

Members Avatar

USA
2015 Posts

Response Posted - 06/29/2010 : 05:31:52

Don B originally wrote; <blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> Possibly air getting into the fuel line?? <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Might be an air leak, I had a fuel line ball crack and suck air the other week.

Edited by - DaveR on 06/29/2010 05:33:50

crispi
Deckhand

Members Avatar

6 Posts

Response Posted - 06/29/2010 : 07:50:52

Ben,

I have 2005 Nissan 9.8 and experienced similar symptoms. It would run fine at high speed, but not at idle or slow speed. I took the carburetor apart and noticed corrosion in the bowl and pieces of corroded material floating around. Since the motor wouldn't run at slow speed I assumed that the slow speed jet was clogged. Turns out that I guessed right. I pulled a wire out of a wire brush and cleared all of the tiny holes, put it back in and it's been fine ever since. Around the same time I noticed that fuel line was deteriorating, so I replace that too.

Since then I've been using Stabil in the fuel to fight the effects of ethanol and water in the gas, which seems to have made the difference.

Hope this helps,
Bob

Edited by - on

bigelowp
Master Marine Consultant

Members Avatar

USA
1788 Posts

Response Posted - 06/29/2010 : 19:46:38

I have an 07 Tohatsu 9.8. I had some similar issues late this past season. Over the winter the engine was serviced by a Mercury dealer) and I was told that these engines are very sensitive to fuel contamination and that at the end of the season the entire fuel system needs to be cleaned and if their is any gas stored in the tank add stabiline liberally. My situation is a bit tougher as the boat is in salt water and is in a mooring all season, so the gas tank and fuel lines have greater opportunity for contamination.

I think the culprit is all the stuff they put in gasoline today combined with the "fine tuning" that newer engines have designed in so to meet environmental regulations. However I now am far more careful with my outboards, including the Honda on my center console as well as the Tohatsu.

Edited by - on

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.