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Author Topic:   Johnson 120 and 90: Same Size, Weight
bwmenemsha posted 02-26-2004 10:02 AM ET (US)   Profile for bwmenemsha  
I am considering re-powering my Boston Whaler Menensha from a 1986 Johnson 90-HP to a Johnson 120-HP. They appear identical. Are they the same block/ weight? Will my current propeller fit? Will l have to change the propeller because of the change in horsepower?
Peter posted 02-26-2004 03:07 PM ET (US)     Profile for Peter  Send Email to Peter     
The answer is no. A Johnson 120 is built on a 2.0 liter loop charged block and weighs approximately 365 lbs. A Johnson 90 is built on a 1.6 liter cross-flow block and weighs something in the neighborhood of 330 lbs. I believe the Johnson 120 may use a V6 gearcase, and if so I think that the existing propeller will not transfer. I doubt that the existing propeller will have enough pitch for the 120.
bwmenemsha posted 02-26-2004 06:28 PM ET (US)     Profile for bwmenemsha    

That's what l was afraid of. Thank you

whalerron posted 02-26-2004 11:01 PM ET (US)     Profile for whalerron  Send Email to whalerron     
Correct me if I am wrong but the Johnson 90 and the Johnson 115 are the same weight. The 115 is not a 120 but it's still a heck of a motor for that boat.

- Ron

bwmenemsha posted 02-27-2004 05:18 AM ET (US)     Profile for bwmenemsha    
Thanks whalerron...thats what l was thinking....l realize that was pretty much the outer limits for the SHA
Bigshot posted 02-27-2004 02:02 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Actually not a bad choice. Your 90 is about 310lbs but Menems are a tad bow heavy:) The 120 has the V4 gearcase but Peter may be right about pitch depending on gear ratio. The 140 has the V6 case. That 120 is a hell of an engine, literally 1/2 the V8.

The cons are that is an old hull, do you really want to stress it to the max?

bwmenemsha posted 02-29-2004 10:14 AM ET (US)     Profile for bwmenemsha    
Bigshot and others thank you for your replies...l geuss you all told me what l already considered or knew except for the weight....l knew the 115 was same frame as 90 wasn't sure if it extended to the 120 tho.
Let me if l may take another bite out of this apple and give you what drives the question....( I may have to re-post this but i'll try here).....Under the guise of what would you do??? Limited budget...nice classic boat...86 johny 90 that runs like sewing machine and does what l want and need in performance. Problem:Tilt and trim FUBAR: Options...find a used t n t of unknown quality w/o gaurentee for several hundred and spend 3-4 hours of changing it out @ $65-$85 per, or buy brand new in box at $650 with same 3-4 hrs,or buy another used motor of similar size (90-120) where everything works and mounts right back up, gives me a good spare motor and time to find a reasonably priced t n t and let me try and repair in spare time in garage. (hence the question of the 120 l may have a good line on) orrrrrrrrrr get a hydraulic jack plate (pt-130) FOR $450ish and that l can install myself. So l toss this question to the experts whose judgement and experience l have gleaned multitudes of knowledge....Thank you
tully_mars posted 03-01-2004 12:26 AM ET (US)     Profile for tully_mars  Send Email to tully_mars     

Coincidentally, a friend of mine just purchased a 1979 Newport powered with a 1993 120 Evinrude. The motor is mounted with a jackplate and runs really well. The top speed we measured last weekend with a 13x19 prop was 46mph. I did not get what the max rpm was.

If you remember seeing my restored montauk, I have the Ficht 75 V-4 which weighs around 365lbs. This has not been a problem on my boat and the weight of the larger 120 doesn't seem to be a problem on this Newport either. Though, in both cases the fuel, batteries etc... are moved under the consoles to help compensate for the extra weight.


bwmenemsha posted 03-01-2004 04:34 AM ET (US)     Profile for bwmenemsha    
Hi Tully...what a pleasent suprise....thought you fell off the radar screen....thanks for that great info...can you comment on the static trim of his boat? My best to your family...will we see them and the newport at BW2 :)
greyg8r posted 03-01-2004 12:31 PM ET (US)     Profile for greyg8r    

How mechanically inclined are you?

I just bought a used tilt/trim unit on Ebay for $150, including shipping, and replaced the TNT in less than 1/2 hour. Paying for 3 - 4 hours is outrageous.

If you are the least bit mechanically, it is a simple process.

Just my dos centavos.


brisboats posted 03-01-2004 01:09 PM ET (US)     Profile for brisboats  Send Email to brisboats     
Because the devil you know (your 86 Johnny)is always better than the devil you don't (used engine). I would recommend staying with your motor and either getting the jack plate or a good used tnt unit. You can still use it the way it is for now.


Bigshot posted 03-01-2004 02:40 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Ditto....keep the johnson and get the CMC or a used TnT unit. I know of a real nice used one that is like new....e-mail me for more info. It is even white. I would think between $2-300 for it.

Hardest part is removing engine which you will need to do with the CMC as well. I have no qualms with the CMC but it is more of a tilt than a TnT from people who have them.

bwmenemsha posted 03-01-2004 04:22 PM ET (US)     Profile for bwmenemsha    
greyg8tr....l am somewhat adept with mechanics and tools but l have been told by several people mech and not....that it is not something you don't want to do unless you really have it together.If push came to shove l would try it...thanks for your "dos centavos" :) Sage advice brisboats...thank you. have my undivided attention sir.
masbama posted 03-01-2004 06:43 PM ET (US)     Profile for masbama  Send Email to masbama     

Was that Newport your buddy bought the one on Hwy 98?

It was for sale for a while.

Bigshot posted 03-02-2004 11:03 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
You have mail....item for sale is a whole FACTORY OMC trim/tilt unit to replace yours new, etc.
bwmenemsha posted 03-03-2004 04:39 PM ET (US)     Profile for bwmenemsha    
greyg8r. too thinking about your post so in conjuction with a possible transplant from bigshot l went ahead and removed the tnt unit just to get the feel of it.You were right....not so tricky on the extraction so l will try and install new one....thanks :)
jimh posted 03-04-2004 08:05 AM ET (US)     Profile for jimh  Send Email to jimh     
[Administrative post]
Bigshot posted 03-04-2004 11:00 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
I love it when a plan comes together! Everyone is happy which makes me happy that I could help. Gonna owe me a beer next time I am up in the panhandle.
bwmenemsha posted 03-04-2004 12:35 PM ET (US)     Profile for bwmenemsha that your way of saying "we have a go"....Come up to Pirates Cove...all the beer you
Bigshot posted 03-04-2004 12:42 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
you will get my e-mail when you get home but......

"Houston...we have a go!"

bwmenemsha posted 03-04-2004 01:03 PM ET (US)     Profile for bwmenemsha    
Can you call me or put an address on here if you want so l can start the process from # here is 850-595-4062...if l aint here leave me on voice mail your address for snail mail
bwmenemsha posted 03-08-2004 02:07 PM ET (US)     Profile for bwmenemsha    
Bigz....Just mailed out the money order for the amount stipulated....thanks....Bob
Bigshot posted 03-08-2004 02:43 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Sorry was real busy on Friday with rendezvous and all. I will see if he will release it to me w/o payment so I can get it to you by weekend.
bwmenemsha posted 03-08-2004 03:45 PM ET (US)     Profile for bwmenemsha    
l sorta figured you would be busy this of these days l would love to make one of your bashes.In ref to t n t....if he will that's fine,if not thats ok too....appreciate your help in this matter.
tully_mars posted 03-12-2004 09:18 PM ET (US)     Profile for tully_mars  Send Email to tully_mars     
Masbama and bwmenemsha,

Yes, the Newport was the one on Hwy 98, and boy did that boat really clean up nice!! 1979 Newport basically in perfect shape. We are getting a new windshield for it now.

Sorry for the long delay in updates, but I have been working way too much.

Since my last post on this thread, he has sold the 120 Evinrude and went in to buy a Suzuki 70 4-stroke. Though, he bought a 115 4-stroke Suzuki 03 model since it was only $500 more. I am curious to see how it will do. Going down tonight to help him rig it up.

BW, I very much hope to see you all this spring. We should start talking soon about another O Beach get together.

Family is doing well, and the Newport should be their too as new members. They are currently lurkers on this site. :)

My best to all of you.


tully_mars posted 03-12-2004 09:19 PM ET (US)     Profile for tully_mars  Send Email to tully_mars     
Oh, and the trim and ride of the Newport was fine. He had the motor on a jackplate and it would run 46 mph on my GPS. (2 adults onboard). Seemed it would trim fine in the entire range.

BW, I think the motor would work well on your boat with the extra weight up front.


bwmenemsha posted 03-14-2004 08:31 AM ET (US)     Profile for bwmenemsha    
Bigz....l have not ridden it yet but the horse is in the barn lol....thanks

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