1988 Nissan 55 HP Help

[Harritwo]

I bought a 1988 Bass Tracker w/ a 55 HP Nissan Outboard with electric tilt. The boat had been sitting for 3-4 years after the original owner had passed away. When i bought it, i put a new water pump impeller in. The engine has a miss at idle, and under full throttle it will only turn up to 3000 rpm and is struggling. If you will continue to run it, it will clear and come up to 4000 rpm. I have changed plugs and tore the carbs down. Everything looks good.

Does anyone have any suggestions on what to check next?

Also can anyone tell me what engine i actually have. THere are no numbers on the motor, the title has a state assigned ID. THe cowling says 55 and Nissan. See pics and any help is greatly appreciated.

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

UPDATE:

After lots of research, I have matched the casting number from the block to a NS50C model engine which translates to a 50 HP engine. I assume that somewhere along the line, someone replaced the cowling or decals or something. So now that we know it is definitely a 50 HP engine. Does anyone have the troubleshooting tips to make it run without the miss?

 

[pvanv]

Re: 1988 Nissan 55 HP Help

Verify your model/serial. Check the serial number tag (visible in your photos on the starboard side). The 50C is a 2-carb, 2-cylinder, 2-stroke. Regardless, both the 50C and the 55 are quite obsolete.

What did you use for an impeller? The factory impellers have been NLA for some time.

Are the plugs fouling a bit (as they would if the mixture is too rich, temperature too low, or the ignition poor)?

Have you de-carboned the motor?

What method did you use to clean the carbs? If your procedure did not include a 4-hour soak in real carb dip, you will want to do that.

Have you verified/adjusted link and sync? Grab you trusty Factory service manual (available from any dealer, including me) and make sure the ignition is properly synchronized to the throttle.

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

Paul,

I used an impeller from a 70 HP outboard that a Nissan Dealer here locally told me would work. THe water flow is fantastic. The tag that is visible in the photo is a State of Texas issued ID so it could be registered. There is a number on the block 2WT81A that crosses to a NS50C in the manual that i have. The Carbs are crystal clean, I took them apart, cleaned them, blew them out with air checked the float setting and put it back together. THe Plugs are new, The Local Nissan Dealer sold me a "Tuneup in a can" That you bring the engine up to 1200 rpm and spray this in both carbs until you have used 2/3 of the can, then bring it up to 1600 rpm and stall the engine with the rest. Then change the plugs and run it hard. It was supposed to help decarbon the engine. You had to use this while the boat was waterborne and not on the mouse ears which is what i did. Yesterday, i put the boat in the water, ran it for about an hour. THe engine will run up to 3000 rpm and sounds like it is starving for fuel. If you choke it, it will die. If you hold it at WOT after about a minute, it will turn up to 4000 rpm under a load. I had myself and my father (A total of 550 lbs) plus a full tank of fresh fuel mixed at 40:1. THis morning i intend to pull the fuel filter, Possibly the pump and check them. THe hose appears good, no signs of deterioration/dry rot/leaks but i will probably replace it. On a side note, THe warm up lever does not work either. Any more suggestions or tips?

 

[pvanv]

Re: 1988 Nissan 55 HP Help

Sounds like you lucked-out and got an obsolete impeller that happened to be on the shelf. Cool. Now that you have it run-in for a while, switch to 50:1 premix. Less smoke, less fouling, etc. The de-carbon treatment was a good idea, but we usually let the motor "soak" (after stalling) for an hour or so. Clearly you are not starving for fuel if choking (richening) makes it worse. If the mixture is wrong (we don't know that yet), it's more than likely too rich. The warm-up lever on the RC box merely pulls the throttle a little. For it to work properly, the cables must be adjusted correctly. You can DL an owner's manual from http://www.nissanmarine.com/tech_talk/owners_manuals.html and that can help you verify correct setup. Also see if you have a super-steep prop pitch. You want WOT of about 5,000 RPM.

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

Paul,

I intend to run a compression test soon, (Hopefully today), What should i expect to see in it in relation to pressure/balance. I.e. (I am an auto mech) should i see around 110-120 with no more than 10% difference or is an outboard have different specs? Also, do you think it might be spark related. Coil Pack, or timing advance? Like in my previous post, it will turn up to 3000 rpm and is struggling then it seems like it willclear its throat and turn up to 4000 rpm. The book that you linked to i alread have and it states that 4500-5500 rpm for WOT. What should i expect realistically? Also, If you look on Page 1 of the book you lonked me to, that is how i discovered that it is a 50 HP vice a 55 HP like the cowling states.

This boat is one my father bought. He is a first time boat owner, i have owned boats since 1979. My first was a 74 Arrowglass with a 85 HP Johnson. Currently i have a 94 Sea Ray 170 W/ a 3.0 Mercruiser I/O with an Alpha i Gen II outdrive (210 hours total time). THis is my first shot an a foriegn engine so i am going by experience with my other boats and my knowledge as an auto mech. Any help you can provide is greatly appreciated and when i determine what i need, i will try and purchase from you.

George

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

I have attempted to test the ignition system and am hoping someone can decipher the numbers and tell me what direction to go to.
When i ohm the wires from the coil Red -Blue i read 1062 ohms, Red to ground is 1059 ohms. No other wires on the cole read and resistance. When i move to the exciter, Red to Blue is read 23 ohms, Blue to Blkack/Ground i read 22 ohms, Red to Black reads open. Is anyone able to interpret these numbers and tell me if either part is good or needs replaceing?

 

[pvanv]

Re: 1988 Nissan 55 HP Help

George,

Every compression gauge will vary from the next one, so exact numbers are not critical (unless they are ridiculously low). The important thing is that they are even. Must be within 10% of each other. 5% is better. 2-strokes typically will have lower compression readings than 4-strokes. Again I feel obligated to remind you that you are working on an obsolete motor. That does not make it bad, but it will limit your options for some service parts.

You must use a good ANALOG meter to do those tests. A digital meter may not provide enough drive to the circuit under test. Also, the meter must use a battery of 3v or less, or you risk destroying the circuitry in the CD.

Grab a Factory service manual (from any dealer, including me) for the techniques and specifications. Skip the aftermarket manuals. There is a whole table of values that you will want to test. Far too many to note here.

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

Can you provide an address for me to order the factory service manual. Locally i have been unable tofind one that covers the1988 year. All that is available is 92 and up. I will gladly purchase from you if you can get it.

 

[pvanv]

Re: 1988 Nissan 55 HP Help

Whoever is marketing Tohatsu/Nissan service manuals based on year of manufacture is quite ignorant. They are serviced by model, and year is irrelevant. You can drop me an email at the office: paul@obersheimersails.com, or give me a call on Monday: 716-877-8221, and I'll be happy to help you.

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

Paul,

I am troubleshooting the fuel system. I have found the fuel filter housing is cracked. THis housing is located on the inlet/suction side of the fuel pump. The fuel pump diaphrams have no pinholes, no dryrot, and no signs of detioration. I am applying JB Weld to the crack in the housing to see if this is my problem.

When i pressure up the fuel line with the line disconnected from the motor, the buld will get hard but will bleed off after about 30 seconds. Is this normal or is my connection on the tank bad? Should it hold pressure or just pressure up and then bleed off like it is doing?

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

I bypassed the fuel filter, the JB Weld did not work, and then i opened the fuel cap on the tank. When i launched the boat, it fired right off, i left the dock and immediatelky turned up by tach to 3500 rpm. As i started to trim up, i could get 3900-4100 RPM by tach. The engine was running smooth at WOT, but at idle it is skipping regularly. I do not trust the tach at this point, but the engine seems to run without struggling now. It sounds like those old popping johhny pump jacks. The plugs look good, but i have ordered a set to replace them with. The local parts dealer did not have them in stock, they will be here tomorrow. I will call your shop and see if you can get me a new filter and housing assy, and various other parts i need. Thanks for your help.

 

[pvanv]

Re: 1988 Nissan 55 HP Help

George, I have a reprint of the Factory service manual available. Also, you can still get the 346022300M FUEL FILTER ASSY, $13.63. We also have the NGK B8HS-10 plugs in stock.

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

Thanks for all your help Paul, I have one more question? Can you provide a starting point for setting the Idle air mix screw? Currently the lower card was turned out 5-1/2 turns, the upper carb 3-1/4 turns. I have run them in and backed them out to 1-1/2 turns, Boat idles good on muffs, haven't had a chance to put in water.

 

[fishingjunky]

Re: 1988 Nissan 55 HP Help

I bought a 1988 Bass Tracker w/ a 55 HP Nissan Outboard with electric tilt. The boat had been sitting for 3-4 years after the original owner had passed away. When i bought it, i put a new water pump impeller in. The engine has a miss at idle, and under full throttle it will only turn up to 3000 rpm and is struggling. If you will continue to run it, it will clear and come up to 4000 rpm. I have changed plugs and tore the carbs down. Everything looks good.

Does anyone have any suggestions on what to check next?

Also can anyone tell me what engine i actually have. THere are no numbers on the motor, the title has a state assigned ID. THe cowling says 55 and Nissan. See pics and any help is greatly appreciated.

I am new to this forum and like the make up of the members. I recently purchased a Nissan 50 hp motor that needed some work and have hunted high and low for a site where I could look up OEM parts through an electronic database. It seems like every site I research only has PDF files which are a pain in the --- to search. A budy of mine sent me a link tonight to a site that has all of the diagrams and parts in an organized easy to search electronic system so I thought I would pass it along. http://www.**********/parts/search/Ni...ard/parts.html

 

[pvanv]

Re: 1988 Nissan 55 HP Help

Thanks for all your help Paul, I have one more question? Can you provide a starting point for setting the Idle air mix screw? Currently the lower card was turned out 5-1/2 turns, the upper carb 3-1/4 turns. I have run them in and backed them out to 1-1/2 turns, Boat idles good on muffs, haven't had a chance to put in water.

You are in the ballpark. Initial setting is about 1-3/4 turns. Adjust after warmed up, in the water (not just on muffs), with a good shop tach, (and good ear) for max RPM. You may have to adjust the throttle stop to stay in range. Once perfect, increase richness about 1/8 turn.

 

[pvanv]

Re: 1988 Nissan 55 HP Help

I am new to this forum and like the make up of the members. I recently purchased a Nissan 50 hp motor that needed some work and have hunted high and low for a site where I could look up OEM parts through an electronic database. It seems like every site I research only has PDF files which are a pain in the --- to search. A budy of mine sent me a link tonight to a site that has all of the diagrams and parts in an organized easy to search electronic system so I thought I would pass it along. http://www.**********/parts/search/Ni...ard/parts.html

There are about 2 dozen websites that sell those parts on the Internet. The real question is customer service, and whether they actually stock anything at all. Some do; many don't.

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

Paul,

Can you tell me if my parts hve shipped yet?

George

 

[pvanv]

Re: 1988 Nissan 55 HP Help

Paul,

Can you tell me if my parts hve shipped yet?

George

Your manual is sitting on my desk; I was waiting for the filter housing. When will you be going back to Texas? I want to make sure your stuff is there in time. Was planning on shipping Monday or Tuesday, once I'm back in the office.

 

[Harritwo]

Re: 1988 Nissan 55 HP Help

Paul,

I am leaving Friday for Texas. Will you ship to have parts by Mon/Tues of next week?

George