Nissan 55 (1988 Vintage)

[Harritwo]

Paul,

I am headed back to work on this engine again, I have a skip at idle. It sounds like an old one lung engine from days gone by. Is it possible to look at the reed valves and see if they are sticking or burnt or similar, are these parts available and are the gaskets available from you or Elvin?

Do you or Elvin have any other advice for where to look? I have cleaned the carbs, rebuilt the fuel system, fix as many vacuum leaks as i can find, and the nipples that are cracked/broke you told me were NLA. I would like to get what i can accomplished on this trip.

Thanks,

George

 

[pvanv]

Re: Nissan 55 (1988 Vintage)

George,

The reeds are visible when the carb is off; Tohatsu reeds are pretty durable though, and seldom fail. I can check on gasket availability when I get to the office in a couple of hours.

In any case of poor idle, you still need to verify fuel, electrical, and mechanical systems (in that order). Assuming good fuel delivery and mix, correct ohm meter readings of the electrical parts, good plug condition, and proper synchronization... then you need to dig deeper.

 

[Harritwo]

Re: Nissan 55 (1988 Vintage)

George,

The reeds are visible when the carb is off; Tohatsu reeds are pretty durable though, and seldom fail. I can check on gasket availability when I get to the office in a couple of hours.

In any case of poor idle, you still need to verify fuel, electrical, and mechanical systems (in that order). Assuming good fuel delivery and mix, correct ohm meter readings of the electrical parts, good plug condition, and proper synchronization... then you need to dig deeper.

Paul,

I rebuilt the entire fuel assembly including new tank, lines, filter, and fixed numerous vacuum leaks. The plugs are new, the ignition checks out fine using the test procedure you provided and an analog ohm meter. The carbs have been cleaned and set, the carbs and shift were synchronized per the manual. it runs great other than the skip at idle. The water pump impellar was changed and have great flow.

Where would you recommend I look next? I am leaving here on Sunday headed home then. Thanks

 

[Harritwo]

Re: Nissan 55 (1988 Vintage)

Paul,

I rebuilt the entire fuel assembly including new tank, lines, filter, and fixed numerous vacuum leaks. The plugs are new, the ignition checks out fine using the test procedure you provided and an analog ohm meter. The carbs have been cleaned and set, the carbs and shift were synchronized per the manual. it runs great other than the skip at idle. The water pump impellar was changed and have great flow.

Where would you recommend I look next? I am leaving here on Sunday headed home then. Thanks

I am in need of a "Nissan Terminal Eye" the part that hooks the shift linkage from the throttle cable cam to the shift dog. Is this part still available and does anyone know where i can purchase it?

 

[Harritwo]

Re: Nissan 55 (1988 Vintage)

Can anyone tell me what WOT is supposed to be on this engine if it is propped right? Currently I am turning 4500 WOT on the prop for 34 MPH by GPS. Am I in the ballpark with this engine as far as WOT and speed?

George

 

[pvanv]

Re: Nissan 55 (1988 Vintage)

I am in need of a "Nissan Terminal Eye" the part that hooks the shift linkage from the throttle cable cam to the shift dog. Is this part still available and does anyone know where i can purchase it?

Can you describe the part a little more? Maybe a part number, or a location on a diagram?

 

[pvanv]

Re: Nissan 55 (1988 Vintage)

Can anyone tell me what WOT is supposed to be on this engine if it is propped right? Currently I am turning 4500 WOT on the prop for 34 MPH by GPS. Am I in the ballpark with this engine as far as WOT and speed?
George

Not too bad. Should max out WOT before 5250. If you have a prop with about 2" less pitch, that might give you a little better hole shot, but probably won't change your top speed much.

You can DL your owner's manual (with specs) at http://www.tohatsu.com/tech_info/own_man_pdfs/Toh55B_70A.pdf

 

[Harritwo]

Re: Nissan 55 (1988 Vintage)

Can you describe the part a little more? Maybe a part number, or a location on a diagram?

Paul,

The terminal eye is the name listed in the manual that I bought from you, It does not list a number. It is the plastic piece that is threaded on to a rod, the threads are 5mm. On the other end is an eye that slides over the pin on the throttle cam and the shift dog. It is black in color, there are two on this particular shaft. The shaft with ends on it is approximately 4-5 inches long.

I tried to call you yesterday, they told me you were not available. The local Nissan dealer doesnt have a clue about anything on this engine and he told me he would research it and then he could possibly order it but he has nothing Nissan in stock for anything older than 93 or so.

 

[pvanv]

Re: Nissan 55 (1988 Vintage)

I was working in the field most of Friday. I will also be doing field work Tuesday afternoon and all Wednesday this coming week. You can always leave a message, so I can get back to you. That sounds like a pretty common bit on the older 2-strokes. I'll see if I can figure out the part number/availability on Monday. What page of the manual does it appear on? As an alternative, can you post a picture so I know exactly which part you're talking about? Thanks...

 

[Harritwo]

Re: Nissan 55 (1988 Vintage)

Paul,

They are shown on Page 42 of the manual in the lower right corner of the page. There are numerous places on the linkage(s) that use this piece.

 

[pvanv]

Re: Nissan 55 (1988 Vintage)

On pages 40 and 41, I see the diagrams for the P type (with remote box) and F type (tiller steered). Are you referring to one of the couplings that use an R-pin to connect to a clevis, and are 5mm female thread at the other, or the coupling that snaps over a ball, and then is 5mm female threaded? Can you post to the forum, or fax or email the page from the manual with the part circled?

 

[Harritwo]

Re: Nissan 55 (1988 Vintage)

Paul, It is the one that is 5 mm thread and slides over a pin on the cam for where the throttle cables are. This is a control box design, not a tiller steer.

 

[pvanv]

Re: Nissan 55 (1988 Vintage)

I think I know the part you need. I can send you a diagraqm, and if you circle the part, I should be able to match it up, as long as it's still available. Drop me a PM with your email address or just email me directly: paul@obersheimersails.com

 

[Harritwo]

Re: Nissan 55 (1988 Vintage)

I think I know the part you need. I can send you a diagraqm, and if you circle the part, I should be able to match it up, as long as it's still available. Drop me a PM with your email address or just email me directly: paul@obersheimersails.comView attachment 208016View attachment 208017

Just wanted to give an update: The eyes were received, installed, and everything is working like it should. Paul, Since the plastic nipples that go behind the carbs were NLA, i sealed the vacuum leaks with RTV. The skip is gone, the engine starts easy, idles perfect in and out of gear, comes up in the power band and planes out easily.

I wanted to thank Iboats members, especially Paul for all the help in troubleshooting and locating parts for this obsolete engine. If i can maintain it, the water pump impeller is now being manufactured by Nissan once more, I should be able to get a few more years (20) out of it.

Again, Thanks to Paul and the rest of the IBoats members for all the help with this engine as well as my I/O over the years.

George