Differences between early 90's Nissan 9.9/15 and 18hp???

tohatsu9.9guy

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I have bought a early 1990s Nissan 18hp 2 stroke (blue, silver cover, blue and red stripes). It is missing the lower unit and a few odds and ends. I also have a 1992 Nissan 9.9B2 that is complete and in near mint condition except for one of the spark plug holes is stripped beyond repair. I was wondering if there was any way to make a runner out of the two? What is the difference in the two motors? Is it possible to swap the 18 hp powerhead onto the 9.9? Will the 18hp cyl head fit the 9.9? It'd be cool to have an 18 hp if possible. Used to have one and it would scoot on my 1436 flatbottom.
 

TOHATSU GURU

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

The only difference are the PH and carb, so swapping the 18 PH to the 9.9 frame is a winner:) The idea of swapping the cylinder head is pointless.
 

tohatsu9.9guy

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

The problem is that the 18 doesn't have a carb with it, and i'm sure tracking one down would be near impossible, and if i did find one it would cost an arm and a leg. What parts will be the same between the two, as far as linkages and electrical, etc? I looked at a parts manual and everything but carb looks to be the same parts. Any ideas on tracking down a carb? My only hope would probably finding yet another parts motor...
 

pvanv

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

What model is the M18? If it's a D or an E2, you can still order the carb new: 3G2031004M CARBURETOR ***'Y $217.87. If it's a C, you are out of luck for new, and will need to locate a donor motor.
 

tohatsu9.9guy

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

it is a C2, and i have a donor motor found that I am picking up this weekend. It is very aggravating that no parts are available for these motors anymore, considering they are not actually "old". OMC parts are readily available back to the 1970s. Are these motors perhaps so good and last so long that the only way to kill them is to not provide any replacement parts?
 

bbstacker1

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

tohatsu9.9guy, I sent you a PM.
 

bbstacker1

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

Not trying to hijack 9.9guy's thread as we are trying to figure out what will interchange between our engines. I am going to look up the part numbers to compare but does anyone know, right off hand, if a tiller arm assy and carb linkage parts on the engine side from a 9.9B2or 18C2 interchange with a 9.9C. Thanx
 

TOHATSU GURU

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

it is a C2, and i have a donor motor found that I am picking up this weekend. It is very aggravating that no parts are available for these motors anymore, considering they are not actually "old". OMC parts are readily available back to the 1970s. Are these motors perhaps so good and last so long that the only way to kill them is to not provide any replacement parts?

Actually OMC does not have complete part availability back to the 70's or 80's or 90's or even back 5 years ago:) No one does. The Jap mindset is based on "reasonable life span theory". Which for Asians means ten years. After that outboards, which are tools to be used rather than collectibles, are considered no longer dependable and are supposed to be replaced. I don't agree with that theory 100%, but there is a lot of truth to it.
 

TOHATSU GURU

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

Not trying to hijack 9.9guy's thread as we are trying to figure out what will interchange between our engines. I am going to look up the part numbers to compare but does anyone know, right off hand, if a tiller arm assy and carb linkage parts on the engine side from a 9.9B2or 18C2 interchange with a 9.9C. Thanx

Yes
 

TOHATSU GURU

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

The problem is that the 18 doesn't have a carb with it, and i'm sure tracking one down would be near impossible, and if i did find one it would cost an arm and a leg. What parts will be the same between the two, as far as linkages and electrical, etc? I looked at a parts manual and everything but carb looks to be the same parts. Any ideas on tracking down a carb? My only hope would probably finding yet another parts motor...

See my earlier post where I told you what the only two differences were. Asking the same question twice is pointless.
 

bbstacker1

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

Tohatsu Guru, please don't blame the last question on 9.9guy, the thread starter, that was not him it was me, bbstacker1. I was just trying to make sure of certain parts interchangeability's as we seem to have two different series of the same engine, 9.9B2 versus 9.9C, that is why I was asking for yours or anyone else's knowledge on the subject. I have since checked the part number books and confirmed what you said that the two tiller assy's will interchange, I was also wondering about the CD boxes but it does appear that they are different between the two according to the book. Thanx
 

TOHATSU GURU

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

His mistake...Post 1 and post 3. And the CD is the same
 

tohatsu9.9guy

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

excuse me for double checking before spending a few hundred $ on a donor motor, we aren't all "Guru's" on outboards :D Just messin' with ya, thanks for the good info.
 

bbstacker1

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Re: Differences between early 90's Nissan 9.9/15 and 18hp???

First off I would like to say that any info on here is new stuff to me, I've never had a Tohatsu engine before so I am learning. Second, the CD question is my mistake I should have looked at the numbers a little closer, the parts manual does show that CD's between the two, 9.9B2 and 9.9C will interchange depending on the serial number of the 9.9B2, seems there was a change at some point depending on Serial # (I am looking at a picture of the early and later ones, it looks like the only external difference is the connectors, would this be correct GURU?). Last, again not trying to cut in on your thread 9.9guy, just wanting to make sure what will and wont as far as parts go, also as 9.9guy said above, thank you to the GURU and fellow brains on these engines, I know I am certainly learning from you folks. Thanx, Bob
 
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