nissan 50hp tldi power issue

[bazzfisher]

It's a friend of mine's outboard and so forgot the model number but it's like ns50b tldi (i'm certain it's the b) , anyways on his last trip he went to lake, motor was fine,,,, fished several hours and then on restart, it was like he was only running on one cyclinder,,,,couldn't go over like 10mph. I went over and he has fire to all three cylinders,,, removed the spark plugs and had autolite plugs in there. He's gonna pick up three new NGK's tomorrow and will try and I also told him about the battery requirement of 850 mca and told him to take the 24series battery out of there with only about 500mca and he said he would swap to a bigger battery. And also found that he had non synthethic marine two stroke oil in use and told him he needs to swap to synthetic. Any chance that the battery issue or spark plugs were causing his problems???? Says he will remove all the non synthetic oil he can and go back with synthetic. Also the battery set up in his boat is two batteries , which not only powers the motor, but double as powering his 24v trolling motor. And also the motor is a 2004 model. Thanks in advance for advice.

 

[Sea Rider]

Welcome to Iboats,

Tech Data to stick with :

Spark plug : NGK 1ZFR6J gap 0.8-0.9 mm (0.31-0.35 In)

Oil : 2 stroles TCW-3

• Tohatsu Premium Oil
• Nissan Marine Premium Oil
• Pennzoil Complete Marine Synthetic
• Pennzoil Semi-Synthetic Outboard Oil
• Mercury Optimax/DFI Oil
• Yamaha Yamalube 2-M Semi-Synthetic Injector Oil
• Bombardier RAM Ficht Oil

Battery : Dedicated 1000 AH battery, on colder climates 1200 AH battery

Happy Boating

 

[bazzfisher]

Rear Admiral, Thanks for the info and welcome. I will pass along the oil info to him and I had already gave him the NGK spark plug number. I will update if the spark plugs or the battery upgrade helps things out....

 

[Sea Rider]

You are welcome, try higher octane fuel than regular, post results, should make a big difference, fingers crossed.

Happy Boating

 

[bazzfisher]

Replaced to the correct NGK spark plugs and put a bigger battery on, even though I think it is only 720mca 27 series battery and ran great until the large fuel line which is under pressure and is highest on the engine came loose. Put and new clamp on it and ran great again. When u get up around 5k rmps the three tach lights start flashing and below that they stay off. I seen other posters post this flashing light problem. So not sure what that is. But I'm gonna try a reset , trying the procedure tohatsu guru posted on another post. Also I checked the charging that the motor itself puts out and the battery volts without engine running was 12.25 v and with it running at a pretty fast idle it was about 12.9 volts.

 

[pvanv]

In our shop, the first thing we would do would be to reset the TPS initial setting, as you suggested. While in diag mode, see what the motor is telling you for any unusual running conditions or logged problems. That voltage sounds low, but it seems to be charging well. Perhaps the accuracy of your meter is off a bit. I would like to see at least 12.7 vdc from a rested battery, so your reading is about 1/2 volt low.

 

[bazzfisher]

We weren't using a rested battery. We purposely ran the trolling motor (24v) on high for a pretty good distance to pull down the battery somewhat. Then I checked the battery voltage. Keep in mind he is only using two batteries total. The accessories are all on one battery, the motor itself is on a separate one and the trolling motor pulls off both. Question is can you get by with that???? Or is he asking for trouble without a dedicated big battery for the motor by itself??? I told him about the info stating you should have at least 850mca or if it's cold weather 1000mca , and his battery for the engine is a 27series 720mca battery three years old. As I stated after we got that broken clamp off that large fuel line reclamped never had any problems on the running unless he got above 5000rpms then the three lights on the tach went to flashing even though it ran great. Thanks in advance for help.

 

[pvanv]

I would go with a fresh battery for starting. At least to test. Many batteries don't make the magic 4-year lifespan. Also reset the TPS.

You may want to see your dealer to see what the motor is telling you is amiss. Or... you can get a Factory service manual, go into diag modem and see for yourself.