1985 Johnson 20hp with a bigger Secret part 1

Folks follow along as I try to get this old outboard running like it should. Maybe way too much detail but I don't want you to miss out on a thing.
Follow the links below for part and tools I used to make this happen:
AMSOIL FULL SYNTHETIC Gear Oil 75W-90 1 Quart amzn.to/3xyjq3d
Heavy Duty Push Button Momentary Start Switch amzn.to/3cUjYso
Petrol Engine Cylinder Compression Tester Kit amzn.to/3iVme6C
marine grade wiring amzn.to/3qfOWAK
Super Clean 101723 1gal. Super Clean Degreaser amzn.to/3iSZp38
Electric starter
amzn.to/3qx0PlJ
CRANK N CHARGE Starter Solenoid Replacement For Johnson, OMC, Evinrude Outboard Motor
amzn.to/3dhgr7o
wiring connector kit: amzn.to/2Um5N91
Lucas Marine Grease amzn.to/3yiKncn
Carb kits:
amzn.to/3f06H33
Impeller:
amzn.to/2S2IXls
Johnson/Evinrude/OMC New OEM GASKET fuel pump
amzn.to/33PdzK0
Aluminum 3 Blade Propeller - RH, 10.5" Diameter x 11" Pitch x 14-Spline
amzn.to/3wjFkH3
Aluminum 3-Blade Propeller - RH, 10.1" Diameter x 13" Pitch x 14-Spline:
amzn.to/3x18avX
Aluminum 3-Blade Propeller - RH, 10" Diameter x 15" Pitch x 14-Spline:
amzn.to/3clMEtM
Video equipment used
Canon EOS M50 Mirrorless Vlogging Camera Kit with EF-M 15-45mm Lens, Black
amzn.to/3tcSCTE
Comica BoomX-D D2 2.4G Wireless Lavalier Microphone System Digital 1-Trigger-2 Wireless Microphone Transmitter & Receiver SLR Clip-on Micro phone,Lav Mic for Smartphone Camera Podcast Interview
amzn.to/3edmYB4
email me at
[e-mail]
mail me at
RMD Creations
PO Box 387
Wellman, IA 52356

[@genesloan3175]

I'm not complaining for long vids, details about what your doing to fix a problem, or short cuts are all appreciated!

[@Michaelsbackyardmarina]

Mr Sloan you are a scholar and a gentleman. thanks for watching and commenting.

[@johnmccarthy7931]

Nice job with the camera shots and the narrative. Your videos are getting better. Thank you for making and posting the video. Enjoyed it.

[@Michaelsbackyardmarina]

Much appreciated! I keep trying. Nice when someone notices. Thanks for watching and commenting.

[@stevanrose7439]

Yahoo. Hay Michael a big shout out to you. Thanks for your video advice and encouragement. I got my buddy’s boat cleaned up and the motor going haven’t been on the water yet but that’s coming soon. Once again thank you.

[@Michaelsbackyardmarina]

That is awesome!

[@terryterry7715]

Thank you for the very detailed video! Nice job. Greetings from Greece. 😉

[@richardelinskas6663]

Dude. You are awesome 😎! Thank you for sharing all this knowledge

[@Michaelsbackyardmarina]

I appreciate that!

[@rickwilson2848]

Your going to give it away to one of your viewers. Which would put you over the top as the TOP REPAIR GUY

[@Michaelsbackyardmarina]

If I had 100,000 subs then I could give away stuff like that.

[@rickwilson2848]

@@Michaelsbackyardmarina when your trying to guess - you ALWAYS look for the MOST possible out of the extraordinary possibility. That was what I was doing. Of course - if you did - then I think that you would get more subscribers and then possibly get sponsors. JUST A THOUGHT. I really do like watching your videos. Much better than “This Old Outboard”. The reason :::: you actually show UP CLOSE showing us what you are looking & doing so that we can learn. You also don’t sound stoned or drunk. Would like so see you do some painting on the motors to make them really look appealing and spruce them up. One think I would like for you to do on EVERY MOTOR for us to learn and that is show us the motor/serial numbers and explain how to read them on each motor before you start

[@joshwhitfordfishing2304]

Great Video!

[@Michaelsbackyardmarina]

Glad you enjoyed it, thanks for watching

[@joshwhitfordfishing2304]

Hope you have a follow-up video coming soon. Ready to see it run!

[@Michaelsbackyardmarina]

I have gear box issues that I was not expecting so I 'm in search of a donor motor, thanks for watching

[@broncodude2828]

My guess on the secret is upgrading the intake and carb to 35 horse pieces 👍 And that powerhead is a runner!

[@Michaelsbackyardmarina]

heck yeah. Great guess

[@helicopterjohns]

I agree with your guess.

[@havocsquad1]

The ports on the cylinder walls for the intake and exhaust act as valves. One can't expect performance increase without solving the issue of what and how much change can be done on ports safely. Not as simple as just throwing on a bigger carb, very common wrong assumption.

[@want2bsailing804]

I am looking forward to the 20 hp converted to a 35 hp . i am trying to convert my 25 hp to a 35 hp at the moment .

[@timothyclingerman5430]

@@havocsquad1 Actually, yes it is. Other than the intake and the carb swap, you will need to go from 1/8" fuel lines to 5/16". Choke and timing will also be augmented, otherwise this does work. thanks all!

[@HookTrucking1976]

this is really cool , I have a 1970 20 horse Johnson Seahorse , I live just north of Watertown SD and i can not get any of the boat shops around to look at it , it is a pull start had it running , conked out on the water havnt had the time to look at since , have a boat stand coming , so i can work on it myself

[@frankweathersbee2553]

I have the same, new coils, points, upper crank seal was dry & soft like leather causing a lean condition on the upper cylinder, runs great now.

[@joemartin6439]

I enjoy your videos

[@Michaelsbackyardmarina]

Appreciate it, thanks for watching

[@ralphbarker7791]

Another great video

[@Michaelsbackyardmarina]

I appreciate that. Thank you for watching

[@64samsky]

Looking forward to when you get it ready and convert it to a 35 HP. I'll be watching!

[@Michaelsbackyardmarina]

I'm excited about that too. Got to get the gearbox sorted out first. I'm focused on this one. It's going to be fun and fast.

[@haroldpowell6860]

U be right.... been there done that.;)

[@kayakangler7683]

Absolutely loving your videos and detailed explanations! What do you recommend for cleaning the old, rotten foam and adhesive on the inside of the cowling?

[@haroldfisher2256]

Would love to see you doing some work on a 50 HP outboard Mercury from the 70's and 80's

[@Michaelsbackyardmarina]

That would be cool! but I don't have any of those.

[@mikedurhan9941]

And the "secret" is........... a 35hp carb and intake! (Or, even a 30hp carb and intake). FYI: 1984 and newer gearcases will swap. They have triple dog gears and clutch dog, they take the same drive shaft, they have the stronger long-shank pinion gear (more bearing support), and they have the same gear ratios. 1983 and older will not swap; two dog gears, short shank pinion gear (less bearing support) and different length drive shaft, but faster gear ratio. Also, 1985 and newer had a different inner exhaust housing, which took a different length water pump pick-up tube than '84 and earlier. GREAT VIDEO. Thanks for sharing.

[@Michaelsbackyardmarina]

Yep, it should be fun.

[@jackchandler2146]

Looking to seeing part 2

[@Michaelsbackyardmarina]

I'm a working on it.

[@johnbohler3229]

That looks like a restricter plate on the manifold intake for the carb

[@k6outdoors]

Looks like that shop dogs were getting a little nosey. Nice running unit!

[@Michaelsbackyardmarina]

Yes, thanks

[@williamweirjr9749]

Have you and or will you explain how to identify the pitch of a prop ?

[@dwayneivie3350]

thought you change out the intake manifold and 35 hp carb on the 20 that what the race boy do., injoy your videos

[@Michaelsbackyardmarina]

should make it a bit faster.

[@russellbailey4443]

I'm looking for a used 20-25 hp tiller with electric start. any suggestions. I just finished rebuilding a 1975 smoker craft lancer. love your channel. defiantly helped me with my 73 Johnson 9.5

[@Michaelsbackyardmarina]

keep your eyes on face book market place

[@mitchz.6234]

Learning lots from your vids Mike.....question, did you ever make final vid on that 1988 Johnson 9.9...and what caused it to die? Can't find that one....thanks a lot.....

[@Michaelsbackyardmarina]

I have not. I am getting back to that within the next month. Been focusing on some larger motors at the moment.

[@mitchz.6234]

@@Michaelsbackyardmarina Can't wait...love the vids!!!

[@darrylmcleman6456]

"Get A Johnson! Make Waves!!!"

[@Michaelsbackyardmarina]

Heck yeah brother.

[@joemartin6439]

To putting an electric starter on a 15hp would be a great video

[@Michaelsbackyardmarina]

If I run across one I will do it.

[@cptnbillyjohnstone510]

Great videos. I'm trying, but the weather is going to put me out of business soon. I have a 20 hp Evinrude, looks near identical. Compression is 70 in both cylinders. Will that work? Suggestions? Thanks

[@Michaelsbackyardmarina]

70psi is a bit low but it will run. Thanks for watching

[@GROCHUZX9R]

What diameter in mm of these throats front and rear in this 35 hp evinrude carburetor

[@Fishpig65]

I have a 84 40hp Johnson on my boat. It's clean. But I don't know if I trust it. Should I get a new 40 at 10 k installed or could I have faith in the 84?

[@thomassmith9305]

I have a 85 Johnson 25hp long shaft and when i took the leg off, it had a plastic spacer. I notice that yours didn't. Do you think it's necessary? There's not a lot of info on them out there.

[@Michaelsbackyardmarina]

Check out the diagrams on MarineEngine.com that's where the truth is. Thanks for watching

[@davidholmes2665]

Hi mike did you ever do a video of the Frankenstein motor out on the water i cant find it

[@Michaelsbackyardmarina]

I'm working on the boat that can handle Frankenstein, then it will see the water.

[@jeremyfallin2882]

Swap out bigger carb and intake for more horse power. All interchangeable like the Johnson/Evinrude 9.9hp and 15hp through certain years.

[@Michaelsbackyardmarina]

you betcha.

[@gennarodimartino5777]

Make sure the shift rod is adjusted all the way it's supposed to be screwed all the way down

[@Michaelsbackyardmarina]

will do.

[@_.R.F.X.L._]

Hello, nice video! how much weight a engine like this have?

[@Michaelsbackyardmarina]

around 60-70 pounds I would guess

[@paulfennell01]

I was really surprised to see the foot of the 35 wouldn’t fit on this motor, it was an 82 foot you tried to put on an 85 power head? Really surprised to see they weren’t congruent.

[@Michaelsbackyardmarina]

me too. thanks for watching

[@danielhaglund244]

Excellent video and great work! One small comment. That never-seize has copper in it right? Copper and aluminium don't mix well. It will corrode the aluminium over time. I would use a non-metallic grease just to be safe.

[@Michaelsbackyardmarina]

Great point!

[@timothyclingerman5430]

@@Michaelsbackyardmarina Yup, better yet you can use the Zinc based anti-seize.

[@boatbeard7767]

Tefgel is great. Or the silver based antiseize specifically for use with aluminium.

[@edwardzbrown]

I have a 72 18hp fastwin with electric start. Can you tell me what battery I should use? I can't make sense of the specs the manual gives me. Thanks!

[@Michaelsbackyardmarina]

honestly you could use a lawn mower battery up to a car battery as long as they have at least 550 cold cranking amps

[@edwardzbrown]

@@Michaelsbackyardmarina That is honestly what I thought, but I spoke to a kid at the store who didn't really sound confident but he got me worried I could go too big and burn things up. I'm totally new to outboard motors. I purchased a boat for $600 on a whim and I'm already hundreds more into it and I've never taken it out of my driveway 😂😭

[@mxtony7]

I have the same motor and I just can't figure out what's wrong with it, it dies without choke, and if I get it going full throttle is very slow, I've cleaned the carb twice and replaced the fuel pump, also replaced the fuel hose coming from the tank as it was the grey one with the liner. Just checked compression both cylinders are at 100 psi, replaced spark plugs still no change.

[@frankweathersbee2553]

Check your spark plugs if top cylinder plug looks lean & lower is rich upper crank seal is junk.

[@jonirish323]

Michael, do you sell any of the motors that you rebuild?

[@Michaelsbackyardmarina]

I do. I put them on market place for sale when I make sure they are as good as they can be.

[@jonirish323]

@@Michaelsbackyardmarina Michael, do you have an email address that I could contact you at?

[@richardcranium5839]

i remember working on an old wisconsin 10 hp wasnt running but if ya gave it a sort of the good stuff it would fire. went to pull the carb there was no governor linkage. hmm. got carb off and seen a restrictor plate. i was thinki wait this aint nascar and this motor predates the pettys. big ole bright lightbulb moment there! lol. limit the air/fuel you limit the output. the more i see outboards the more i see this principal in use.

[@Michaelsbackyardmarina]

restrictor plate boating is what we have going on here for sure.

[@evinrudej]

Ever think of changing your user name to miaches backyard Mariana ? Great channel

[@Michaelsbackyardmarina]

Thanks for watching and commenting.

[@thediycarmedic4822]

Float should be level and 1/16th above gasket surface.

[@Michaelsbackyardmarina]

That's is the first thing I'm going to check, I'm sure I set it a little too rich.

[@davekimbler2308]

Are you going to tomahawk in August ? If so stop by and see me down towards the end on the left next to Neptune Ned !

[@Michaelsbackyardmarina]

Probably not but it looks like a good time.

[@davekimbler2308]

@@Michaelsbackyardmarina sure is and lots of parts and outboards for sale cheap ! I bought 4 motors the year before last and made $2,000 profit and a bunch of Martin parts and even a free 12 ft. Boat ( aluminum ) and a few collectibles ( flags , t-shirts , hats and oil cans )

[@joeevens1368]

Well. Mike Durham threw out some excellent info that should be archived There are a bunch of other details that will likely come to light on this thread that will help folks get more power out of these 31.5 cu. in. jonnyrudes for those who pay attention. It's all good, it seems, because, done right, the motors seem to run better with all the best parts and tweaks. No doubt that my input is incomplete and a bit dated, so I" welcome any other info out there. The racers run the hell out of these motors, reliably, mostly. I'm talking fishing motors......Here is a start.....There are some variables, but in general, you want the 30 hp carb and the later model intake manifold. The later intake manifolds flow better, and have more volume. The older manifolds come close in power, though if matched to the carb throat. The 35 hp carbs have the choke obstructing flow, so the primer carbs flow better.. There are small changes in venturi size thru the years that make a difference, as well. I'm currently running a later model 70 hp carb with the black plastic top that has a slightly larger venturi, but with the jets from an old 35 hp. Later model 30 hp gearboxes are lower geared and will swing a bigger prop, good for many fishing/bigger boat motors. There are differences in the exhaust tuners thru the years and hp of the motors that should be considered . The early power heads make more compression/power. 1979 and 1980 motors, at least the four that I have, run 145+ compression. After about 1980, factory new compression was reduced.....In 1985' 35 hp became 30 hp, with the change from rating power from crankshaft to prop shaft, so there are no 35'hp motors., though I think that a combination of all the best parts mentioned probably push 35 actual, tractable, real world hp. Cheers.

[@Michaelsbackyardmarina]

Tons of great info. Thanks for watching and commenting.

[@timothyclingerman5430]

@@Michaelsbackyardmarina Hi All, great Info, but as the host mentions all the time, Fuel Lines! when doing the Mod change fuel lines to that of the output of the pump, you should find that it will match the input lines of a 35HP. combine that with the upgrades mentioned and it should boost at least 10HP. Pay close attentoin to the flow of water cooling system however, the higher fuel content after the boost, will cause more internal engine heat and if cooling system is not in good working order......well, you know.

[@phillipedwards5562]

Try McMaster Carr Supply for fuel line, might be cheaper.

[@Michaelsbackyardmarina]

I will check it out.

[@plantomm12]

hello what is the best measure of oil and gasoline for a jonhson 15 hp from 1985

[@Michaelsbackyardmarina]

50:1

[@markrobertson8816]

What would make it super hard to pull over

[@Michaelsbackyardmarina]

could be a number of things. Without being there hard to say

[@gennarodimartino5777]

The float adjustment is an inch and 1/8

[@Michaelsbackyardmarina]

Thanks for the tip. Thanks for watching.

[@jtautoflowerguy1576]

Thats an incorrect measurement 1 inch and a 1/8 is way to big of gap just trying to.make sure you guys have correct information

[@oscarvalmart]

I have a 1988 15 hp johnson and it is pull start. Is there a kit to make it electric start?

[@Michaelsbackyardmarina]

I have seen them with electric start. I have not seen a kit you can purchase. Best bet is to buy used parts or a parts motor with electric and rob the parts off of it.

[@oscarvalmart]

@@Michaelsbackyardmarina OK. Thank you for the advise. I am from Mexico so it would be difficult to find them. Do you recommend trying to find them maybe on ebay?

[@gmansmith1907]

Opening the hole on the plate between the car and the motor and swapping out the carburetor with a different one

[@Michaelsbackyardmarina]

pretty close, thanks for watching

[@reelnraideroutdoors2932]

I have a 1983 Johnson 25 just wanted to know if I can do the same and make it a 35

[@Michaelsbackyardmarina]

Not sure. You would have to do the research

[@masterful7574]

Remove the restrictor plate, put on a 35 hp carb...presto chango a 35. Unless it needs a different tuned exhaust pipe like the conversion from 9.9 to 15 needs.

[@Michaelsbackyardmarina]

you got it dude.

[@wish2fish37]

So. What makes this one start so easy?My 20hp 1985 starts fairly easy but not like that one.

[@Michaelsbackyardmarina]

Timing is everything I'm finding out.

[@wish2fish37]

@@Michaelsbackyardmarina I thought timing on these didn’t really affect anything until full throttle advance?

[@joepostada8317]

Would like to no if I can get My Johnson 25 two stroke up it to a 35 Hp is that possible

[@Michaelsbackyardmarina]

I do believe you can. I am planning on doing one myself

[@joepostada8317]

Let me no as soon as you do that I’m trying to find someone to do my motor and will it hurt the motor by pumping the horsepower up ?

[@rickwilson2848]

Where do you live at?

[@Michaelsbackyardmarina]

Well I'm not sharing that with anyone, thanks for watching

[@harveynewman4333]

they use 3/16 fuel line up to 70hp on OMCs

[@Michaelsbackyardmarina]

interesting

[@harveynewman4333]

@@Michaelsbackyardmarina they have used that size of fuel line on 70hp and under since i started repairing them in the mid 70s. still work on them now.

[@virgilmuirhead346]

When are you gonna make another video on this engine

[@Michaelsbackyardmarina]

I'm working on the video to fix the gear box so I can work on the motor again. Thanks for watching

[@virgilmuirhead346]

@@Michaelsbackyardmarina awesome I love the videos I'll watch them all day! I've got 6 Johnson's. 2 8hp, 2 25hp and 2 35hp that's all I run is omc Johnson or evinrude. Your awesome man keep at it

[@garyrichard2177]

I have a 40 hp 1985 and need a air box

[@haneysgarage2631]

I think your going to bore out the intake to match your Carburetor to make it a 25HP

[@Michaelsbackyardmarina]

That's a pretty good guess

[@haneysgarage2631]

Thanks you can get it to a 35hp but you need the 35hp carburetor and the tuned exhaust and I believe different reeds.

[@BrandonsGarage]

I need to find a bigger secret.

[@Michaelsbackyardmarina]

Heck yes you do. LOL. Thanks for watching

[@user-uc9dy5is2g]

I need a 10 hp out board. I have a 15 hp gear won’t go out of neutral was running but stopped when I put it in reverse now it won’t start. Live in Ohio, Charlie

[@Michaelsbackyardmarina]

You should be able to source one locally, thanks for watching.

[@user-uc9dy5is2g]

@@Michaelsbackyardmarina Thanks

[@gillgetter3004]

The starter is more than ten more like sixty for it

[@Michaelsbackyardmarina]

yes it is.

[@chriseisele9969]

Michael the 20 can be a 35 with the 35 carb thanks Chris

[@Michaelsbackyardmarina]

You bet

[@davemartin1534]

Long story short so I've been told that you can up the HP by a carb change.

[@Michaelsbackyardmarina]

Along with a couple other items.

[@jtautoflowerguy1576]

3 1/16ths gap from float to carb housing

[@Michaelsbackyardmarina]

Thanks for the tip. Thanks for watching

[@davekimbler2308]

Change carb to make it a 25 hp would be my guess !

[@Michaelsbackyardmarina]

that's a good guess but I'm going bigger.

[@davekimbler2308]

@@Michaelsbackyardmarina those 22 c.I. Blocks might only go to 25 to 28 hp not 35 but I could be mistaken ! Lol. Ya could put one on top of the other and make a tower of power OMC , all you’d need is a 4 lobe cam ! Lol

[@timothyclingerman5430]

@@davekimbler2308 It's the 521cc motors that work really well for upgrade mod.

[@davekimbler2308]

@@timothyclingerman5430 the 22c.I. Blocks can only make up to 30hp unless you do some serious modifications and that wouldn’t make sense because of costs !!

[@toddstevens8704]

QA11

[@Michaelsbackyardmarina]

?

[@joemartin6439]

Very noisy with your microphone right close to the engine

[@Michaelsbackyardmarina]

for sure it is. I love motor noise, what can I say.