Nissan/Tohatsu 4-stroke 18 hp o/b vibration

[saturna]

I'm replacing a 15hp Evinrude 2 stroke on my 15 aluminum boat. Bought a new Nissan 18 hp 4 stroke and find it vibrates badly from about 1000 rpm on up. Still in first two hours of break-in. Anybody else have this problem? How about with other similar 4 strokes? Dealer says engine is operating as per standard; problem may be combination of this type of boat and motor.

 

[SeaSnapper]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

I have the same motor on my boat. Can't say that I've noticed any vibration. Has the dealer or mechanic gone out on the water with it? Running it at the shop, if thats what they did, doesn't always tell the true story.

 

[portercat100]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Did you fix the problem? Did it go away with further break in? Just curious, since I'm thinking of buying the same motor. It seems to be the best deal for a new 4-stroke on the internet.

 

[SeaDawg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

I reviving an old post, because of sticker shock from a 20 HP Honda. Does anyone have this 18 HP 4-stroke Nissan on their boat, and do they like it?<br /><br />Thanks in advance.<br /><br />Ron

 

[cobra 3.0]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

I have the 15 hp Evinrude two stroke. It's a terrific engine and is very smooth. I'm surprised to hear that a four stroke is rougher. Why buy a four stroke except for quieter and smoother operation? I know they polute a lot less and save on gas. Something doesn't sound right with that motor.

 

[SeaDawg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Yea, I'm looking at getting a 2004 18 HP Nissan 4-stroke, That's why I wanted to see what others that had them thought about them. I figured "reviving" this old post would keep all 18 HP Nissan comment together.<br /><br />Hopefully some 15 - 18 HP Nissan 4-stroke owners will respond.<br /><br />Ron

 

[cobra 3.0]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

One thing is sure. You won't hear about vibration off a Honda motor! I think they cost more for a reason. What's the difference in cost? (You only pay it once.)

 

[SeaDawg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

From the prices I have gotten, it's around $5,000 for a 2004 Honda 20 HP, compared to about $2,500 for a 2004 Nissan/Tohatsu 18 HP 4-stroke. The Honda weighs about 10 lbs less and has a couple more HP, but that appears to be the only significant difference. I'm comparing a 20" shaft, electric start, tiller version of the motors. $2,500 is talking to me............<br /><br />On a side note, I've owned 2 Honda motors in the past (a 1995 15 HP and a 1996 25 HP, both purchased new) and absolutely loved both of them. But I also have owned a 1997 Mariner 50 HP 4-stroke(bought used), and liked it just as well as the Honda.<br /><br />The dealers that sell different brands of 4-strokes really don't have anything bad to say about the Nissans, except that they cannot compete with pricing of Cabelas and the internet on the motors, and they only get the service work sometimes. But, they do admit, even service work is better than no work, and it is fast making these engines become more popular, because of the drastic price difference from the other small 4-stroke outboard manufacturers.

 

[cobra 3.0]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

WOW! Two motors for one! I can see why you are looking at the Nissans! <br /><br />The Merc 50 was a Yamaha venture. Yamis are great motors too.

 

[jackrg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

I bought a 18 hp Nissan from Cabella's in 2001.<br />I couln't find a better deal out there.<br /> As far as the vibration is concerned, it is there. I have it mounted on a 2000 Lund adventure<br />series 16 ft. It pushes the boat @~24mph/gps.<br />It's great on gas. The vibration is in the trolling range, It's alittle anoying but, managable.You can adjust it out with the throttle.

 

[SeaDawg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Thanks Cobra and jackrg. Yea, the "motor hunt" is narrowing down for me. I got the J1250 and a trailer at the recent Baltimore boat show, and the Honda dealers came down to $3,150 for a 2003 BF20 with electric start and long shaft (still too much for my wallet). And the best Yammy 2003 15 HP motor price was $2,200. Surprisingly, the Suzuki/Johnson dealers were in the $2,600 price range for their 15 HP motors, and they would not budge on price.<br /><br />But Cabelas still appears to have the best deal for the HP, around an $800 savings for 18 hp, compared to the 20 HP Honda (long shaft and electric start). Nissan dealers have already told me that they will put me "on the end of the list" for repair issues though (no big deal for me, because I repair my own motors anyway).<br /><br />I also called the Nissan factory directly (at 4:00 p.m.)yesterday, and they were very honest and open over the phone about their motors. Their website was acting up, and they have already fixed their website problem too.<br /><br />I e-mailed the factory about the vibration problem, because I would use the motor for slow trolling for flounder and stripers, and I don't want vibration at trolling speeds.<br /><br />I'll see what they say before getting the Nissan.........<br /><br />Ron

 

[jackrg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Sea dawg, If you get a response from Nissan, it would be interesting to hear what they say.<br /> As far as repairs go. The only problem I've had was the kill switch started acting up, the engine wouldn't shut off. After looking under the hood i found that the black ground lug that grounded the switch to the engine block had worked it's way loose(the wire was crimped to tight to the lug at the factory) Wire broke. After fixing that I've had no problems. I've got ~ 50 hours on this engine, it doesn't get much use. The wife and kids like to go out in the bigger boat.<br /> Good luck.

 

[SeaDawg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Nissan responded promptly, and here is a copy of the e-mail reply they sent me:<br /><br />"The 18 HP is a 2 cylinder. We bring both cylinders up at the same time<br />every revolution to elongate the power curve (standard design for 2 cylinder<br />four strokes, otherwise the power curve is flat). So there is going to be a<br />certain amount of vibration of the engine. To combat this issue we<br />incorporate special dampeners on the bracket. Not only do we have front and<br />back dampening, but also side to side. The handle and bracket stay fairly<br />stable, but the engine does have a certain amount of vibration. Whether it<br />to much vibration seems to a matter of perception. I have customers who say<br />it is the smoothest engine they have ever run, others who complain of<br />vibration???? Please contact me if you have any further questions. "<br /> <br /><br />I did not edit anything from the e-mail, and I agree with their rationale, and it does not scare me from buying this particular engine. <br /><br />I now know to possibly expect a little low end vibration, which I realistically would expect from any two cylinder engine.<br /><br />The 25 HP Honda I had was a 3 cylinder, it ran very smooth at all speeds, but it weighed 50 lbs more too.

 

[Salmon Tub]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

It is the way it is. I don't own any of the Nissan/Tohatsu 4 strokes, I have a bunch of their 2 strokes, but I have friends with their 4 strokes, and have ridden in boats with them. The key is to understand the concept correctly. I have noticed that on average, all of the 2 strokes seem to vibrate. This is because they use softer motor mounts and dampners. Turn the steering wheel all the way to one side, or even grab the engine to hold it, and most of the visible vibration is gone, you still will feel it though. Most auto manufacturers incorporate things like balance/silent shafts, larger flywheels, smaller displacements centered on intake and exhaust for performance and such to smooth out their engines, Nissan/Tohatsu has a much more straight forward approach. You really don't need the extra moving parts, so why bother. The vibration has little impact on the longevity of the engine, and smoothes out at higher RPM. Look at it this way, why does Catapillar not use corinthian leather in their tractors? Same kind of mentality. Otherwise, they are bulletproof. I often wondered if you replaced the stock mounts with stiffer rubber, what would happen, it may transfer more of the vibration to the transom. For the most part Yamahas are smoother running, but packed in very tight under the cowel. By smoother I mean less vibration, not variance in RPM's. I must say though, it does get annoying from time to time, when trolling for long periods, unless the bite is wide open, but in that case, who's got time to notice such things, fish on!

 

[DJ]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Interesting how they fire both cylinders at once, not unlike some two cylinder motorcycles of yesteryear.<br /><br />By the way, the Mercury "Classic 25" two stroke does the same thing.

 

[SeaDawg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Well, I could not justify the $800 - $900 difference in price of the 20 HP Honda to the 18 HP Nissan, so I ordered the Nissan last night.<br /><br />When I get it, I'll post how it performs, and I will compare it to the 1993 15 HP Honda, the 1995 25 HP Honda, and the 1996 50 HP Mariner (all 4-strokes) that I have owned in the past, and post the results.

 

[SeaDawg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

It came in - I got my new 2004, 18 HP 4-stroke Nissan, and it started on the first "one hand" rope pull, in 35 degree weather - unbelievable!<br /><br />It purred like a kitten, and I ran for 20 minutes or so (I put .3 of an hour on the self powered hour meter I installed on it).<br /><br />I then thought about this post, and I restarted it, and felt the engine and engine stand for "vibration". <br /><br />I was running it on an engine stand, and I did not feel that it vibrated "abnormally". It is a 2-cylinder engine, so it has "some" vibration, but I would not have even thought about it, if it had not been for this post.<br /><br />Sooooooo, I'll give another update in a month or so, once I get it on a boat and take it out perch fishing.<br /><br />Bottom line, (so far, after 20 minutes of playing with it), I really like it. Easy to pull start, excellent electric start, good idle, very quiet - these are my initial observations for now.

 

[james082273]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Hey DJ, I don't think they fire at the same time. It's kind of like a small block chevy, #1 and #6 are at top dead center at the same time but since we're talking four strokes they take turns firing on each revelution .

 

[SeaDawg]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

Been a while since I posted, and since I have been keeping this one alive, here's some more.<br /><br />I've put 6.6 running hours on the 2004 18 HP 4-stroke Nissan (I have it on a small Carolina Skiff), and it runs well, starts well, and vibration is not an issue. I got the electric start option, but because the fishing trips have been "spur of the moment", I've left the battery at home and rope started the motor. It starts the first pull, sips fuel (I've use 1.5 gallons so far), and I would buy another one.<br /><br />The only issue I've had is the motor is 2" too low for the transom of the CS - the motor is a "long shaft", and the skiff transom is 20". <br /><br />I'm making a polycarbonate "jackplate" that will raise the motor (basically a 1 1/2" thick block of "tougher than lexan" material) that will let me raise the motor, and I'll post on how it works.

 

[lewkster]

Re: Nissan/Tohatsu 4-stroke 18 hp o/b vibration

a freind of mine bought the 30 4 stroke and loves it. I bought a 40 2 stroke and am also happy with it. not same size motor, but they do seem like good units. specially for the dollar value!