Johnson outboard 9.9 with a big secret part 1

I purchased a Johnson 9.9 and discover something unique about this outboard, watch and find out what it is. Plus it is getting some awesome upgrades
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Merchandise link below
/ @michaelsbackyardmarina

[@alegriarick]

I purchased a 15 HP Johnson in 1982 in Manaus Brazil to use in upper reaches of Amazon tributaries. It was a factory modified motor based on the 10 (9.9)HP motor with the stouter lower unit from the 25hp model. It had a heavy duty low pitch propeller. The advantage was that it was light weight enough to haul it up some of those 50 ft high river banks. We mounted it in a 21ft aluminum boat and travelled 10 days for our first trip to an Indian village. We put on several thousand miles of travel with that boat and motor before it was stolen. But it was a good reliable motor - not fast, but it pushed a load of 1100 kilos easily. We often had to jump over logs, and under logs to get upstream. Thanks for bringing back a fond memory!

[@donparker8246]

A 9.9 to a 15hp. One of Johnson's little secrets to keeping their product line up. My Dad worked at the Waukegan plant for 33 years. He told me this secret years ago.

[@troykitchens9924]

Mike I was a master tech on OMC AND Johnson/ Evinrude outboards back in the 70s thru the late 90s. You are correct on the conversion from 9.9 to 15 hp. I you check the parts manual for your model year you will find that there is a shim that is fitted under the reed plate that will allow the reeds to open a bit further which in turn allows for the extra fuel. Also the difference in carburetors is the size of the venturi.

[@Michaelsbackyardmarina]

Absolutely correct. So many folks want to argue about it, it crazy. Thanks for helping me set the record straight with some folks.

[@rbnhd1976]

Stephen C Foster park near me has a 10 horse limit on boat motors so everybody used to buy 15 horse and order a 9.9 cover to conceal their deception. The Rangers wouldn't look too hard back then if you weren't causing trouble. The first 2 digits of the vin plate is usually either 9.8, 9.9, 10 or 15, and you can change the 15 to 9.8 if you're careful and smudge the whole plate a little. Just a little outlaw fun from back in the day.

[@rbnhd1976]

I should've read more comments lol

[@ExploringCabinsandMines]

Mines the opposite its a 9.9 with a 15 horse cover.

[@nickalasd.1091]

@@ExploringCabinsandMines Well sir That is call getting ripped off lol

[@ExploringCabinsandMines]

@@nickalasd.1091 Well sir I got it for free soooo .....not.

[@kerrypitt9789]

I think if you look around Canada you will find thousands of that year or model in Evinrude and Johnson outboards. They seem to be a bullet proof little motor! I enjoyed your presentation! Hello from Canada! Please stay safe!

[@robertskinner6487]

Your right I,ve owned two the only reason I bought a second one is because someone stole my first one ( I am from ontariariario)

[@geckokid1019]

Our family have bought 10 9.9’s from 1974 and they all still run today

[@SeeMooreVids]

Just so you know, I didn’t think you were “long winded”. You made sure we in the audience understood where you were and where you’re headed. I have a 1990 Johnson 8hp. I o all my own work as well. Thanks. Headed to Part II .

[@Michaelsbackyardmarina]

Cool, thank you for watching.

[@jiefflerenard1228]

Hi. As long as I can remember the 9.9 Hp and the 15 Hp were the same engines with the 15 just boosted (sorry I was early). In my book at first look this 88 is still a beauty .Being that old the main problem will be the rubber parts craking. These were the last years of the best quality engines and Envinrude-Jonhson ruled the water for their no nonesense Chevy style. Good luck

[@lesliekeyser3420]

As a Master mech for Jonson I will say that you do a very good job and your Information is also very good.

[@Michaelsbackyardmarina]

Thank you.

[@timfrederick9992]

Always agree, when you purchase something used, check and change oil, plugs.fluids, filters, etc so you have a starting point of your own for future maintenance.

[@Michaelsbackyardmarina]

Absolutely. Thanks for watching and commenting

[@royormonde3682]

When grewing up one of my neighbors at the cottage had a 9.9 hp, but in fact was a 15 hp with 9.9 badging. They are exactly the same size. He won the 10 hp and under catagory at our local Regata for years and has a shelf full of trophies to boot.

[@GMC1961]

I have owned a 1982 15 hp Johnson for 20 years...the 9.9 and 15 hp motors were exactly the same. All parts were I nterchangeable.The only difference between the two motors was the jetting in the carbs and the timing.The 15 ran at a little higher rpm

[@fishhuntadventure]

Cheating must have made him so proud of himself

[@74nova36]

@@fishhuntadventure for real! What a jerk

[@jonmartin6451]

Knowledge Drop: 9.9 & 15hp OMC engine cowls are interchangeable as well

[@d_ward4871]

I just bought my first boat, a 14 foot that came with a free 1994 9.9 Evinrude 2stroke. Guy said it had very very low hours but didn’t run. I had to fix a couple wires that were chewed from mice. The air box was packed with acorns, and the carburetor was thoroughly cooped up. I took it all apart, cleaned the carburetor,got the Jets passing air, put it all back together and it fired up on the first pull, purrs like a kitten. My one concern, it seems to not squirt the fresh water at idle but does very well when throttled up slightly🤨 I hope it’s not a problem. I’ve only ran the motor 2 times for a few minutes so far, haven’t taken it out yet. Your video would’ve help me a lot if I saw it before I did all the work 😂

[@MrTomtusti]

I have a 1986 Johnson 6 hp with the original spark plugs. I have used it every year all summer.

[@michaelshallett6665]

Very informative..I really like the info on the difference between a 9.9 and 15.. thinking I'm gonna build me a sleeper for the water

[@Michaelsbackyardmarina]

Go for it!

[@vidguy007]

A 9.9 is a 9.9 because some lakes and operator ages are limited to "below 10 hp." Often a 15 has the 9.9 cover on it. And yes, a 9.9 and a 15 are usually identical engines as you explained. That is a nice little outboard.

[@misters2837]

True... Most of the 9.9's I know of are a 15hp with a smaller carburetor to restrict the power down to 9.9... Oldest trick in the book is to get a 15 carb off one with a junked bottom end.

[@georgeprevost8180]

Good day, a correction should be made about proper mounting height of the outboard. The anti-ventilation plate {the wider wing on each side of the gearcase}, should end up between flush with the center bottom of the hull and up to 1.5" inches below it. If it is mounted any lower it will act like a hook and create drag, or if mounted higher the prop will over ventilate and you may end up with less water being sucked up by the water pump. This rule may be different with boats set up for racing, but they also different or modified parts to achieve the desired result.

[@Michaelsbackyardmarina]

Thanks for the tip. Been a whole bunch of folks commenting about my mis speaking about this. Thanks for watching

[@RobFranklinROX]

We had an Evinrude dealership in the 80's. (Roshway Sales and Service, Dryden Ontario). Same parts book and service manuals for the 9.9 & 15. I don't remember the parts book listing different carbs, but I do remember it listing different cylinder heads. (And I suddenly remember I'm gawd awful old)

[@timevans815]

I have always wanted a 9.9 Johnson!!

[@seau2007]

Getting dad's old 9.9 Johnson and '57 Johnson 7 1/2 he bought new like the 10hp. Mine is a 1980 maybe. I subscribed and probably will contact you when they arrive. Had them shipped from Maryland to CA. Arrives tomorrow or Tuesday hopefully. May do your upgrade to make it a 15hp. Many thanks for your video. Steve

[@Michaelsbackyardmarina]

send me an email of them running when you get them done

[@WarpOne]

I thought you should know - although the Comet cleanser has no abrasive, the Magic Eraser sponges DO have embedded abrasives. That's why they work so well - but they can leave fine scratches, so go easy with them.

[@Mboyes1]

I own a 9.9 Evinrude. I've never had to take the starter off to get the carb off. True, it's easier with the starter off, but it's not necessary.

[@philskype101]

You get my thumbs up for using a pry bar instead of a screwdriver!

[@charlesmawhiney7831]

I have a 9.9 Johnson 1984. I purchased this motor brand new and as such have had it it's entire life. Believe me go back to the Champion plugs. Mine still runs as good as new.

[@LiveWire-it8zr]

Up through the mid 90's a lot of local legislature made you register boats with engines 10hp and over. A 9.9 cover on a 15hp was an easy work around.

[@rolandbrantley3112]

Like the explanation very complete even someone like me most experience is with a paddle can understand what you are doing

[@leeadams5941]

I also had a 15hp model and it was one of the best motors I ever owned..sold it when I sold the boat

[@Michaelsbackyardmarina]

They are reliable for sure.

[@billwalter100]

Thanks for your video. My 13yo son just bought a 1977 Johnson 15HP. It has low compression in both cylinders (65 PSI) and no spark. We are pulling it apart and trying to get it going. Tested with a voltmeter and found good charge to power pack and nothing beyond. So ordering a new powerpack. Next we took the head off - the head gasket looked OK but we found the thermostat was rusted. Piston rings look OK too. So not sure why compressions is so low in both cylinders. Anyway - really enjoyed your video thanks.

[@garygerard4290]

short shaft / long shaft measurement" I believe you measure from the top of the transom to the cavitation plate

[@Michaelsbackyardmarina]

You are correct

[@edwardnorlander6212]

I have a 9.9 evinrude outboard ,I found out that pulling the flywheel makes it easier to remove and replace thw pull starter , I like your vidoes thank you keep up thegreat work .

[@Michaelsbackyardmarina]

Thanks for the info, thank you for watching and commenting.

[@edwardnorlander6212]

@@Michaelsbackyardmarina you are welcome , I would like to know where you are located please . I have miht have 2 outboards I would like to possibly trade for one good prefer at least 20 hp

[@Michaelsbackyardmarina]

@@edwardnorlander6212 I'm in eastern Iowa. What two outboards are you talking about trading in?

[@Ashoud_Anobetah]

37:03 solid gem 💎 👌 thanks for making an informative and inspirational video!

[@Michaelsbackyardmarina]

Glad you enjoyed it!

[@tankdog03ify]

I've got a 91 9.9 electric start long shaft, thing runs great.. matches my 1990 60hp tiller. The value of these old 9.9hp motors are up, pd $300 for mine.. will easily sell for double

[@Michaelsbackyardmarina]

It's because all the new stuff prices are driving up old stuff prices, thanks for watching

[@raymondalbert8505]

Since you use Snap on get a 1/4 Dr. 7/16 universal socket 6 in extension and after you remove pull start you can get the nut off the carb real easy.

[@ronaldnelson7204]

Just to let you know - those years of Evinrude and Johnson have a problem with the water tube grommet at the power head. The problem shows sooner in salt and brackish water. What happens is the Grommet swells up into the water port at the power head and stops the flow of water from the pump. The new grommets are made a little shorter above the internal groove to stop the upwards swelling.So if your motor blows steam out of the the indicator port for the water pump now you know why. I was the first mechanic to diagnose this problem. there is a service bulletin for this problem.

[@Dangbo3030]

I had a 25 hp Evinrude and it had steam coming out of the exhaust even though it was peeing good. Now I know what the problem is. How hard is it to get to? Can it be accessible once I pull the lower unit?

[@ronaldnelson7204]

@@Dangbo3030 No you have to remove the power head then you will be able to get at the inner exhaust housing which holds the water tube and grommet to the power head. But if the tattle tail stream is peeing water steam in the exhaust is normal.

[@aleckbrown1915]

Thank you Mike really enjoyed it and learned a lot

[@tomhath8413]

The only years that the 9.9 and 15 were identical except for the carburetor were years '74 to '76. After that the intake and exhaust manifolds were different; just changing the carb won't be a full conversion. Also, you said there was silicone under the water pump; I believe 3M-847 sealer should be applied there when you have a metal water pump. Per Evinrude's website the QL77JC4 plug should be gapped at .030, although the NGK equivalent does call for .040 It really sounds like the shop that the previous owner took it to cheated him big time.

[@tomhath8413]

@Russ Gallagher In 1979 they added a shim, part #325038, (one for each cylinder), behind the leaf valves and under the stop plate for the 15 hp, apparently to allow leaf valves to open up more at higher RPM, giving the motor more fuel in the air mixture.

[@tomhath8413]

@Russ Gallagher Yes, obvious typo. The point is that there's more to getting 50% additional hp than just a bigger carb. I've heard that the early motors were more like 13hp from the factory. And that's only at WOT, anything less than wide open and you have a 9.9 that doesn't idle well (I had a 1974 Evinrude 9.9 with the 15 carb, changed it back to 9.9).

[@timfrerichs247]

Just seeing this now but I just replaced the plugs in my 14 hp spl and it shows the same thing as far as the gap goes... .030

[@JOHNOhnstad-z6c]

I've got a 25 short shaft you taught me things i didn't know thanks😊

[@mrsjohnson1743]

Why do I watch this? 😆 Nice channel. Now I have another subscription to go along with the guy who digs junkyards for cars to fix and the bus grease guys😃. It is all so interesting.

[@ianmacke7]

Good video, very helpful and informative on John 9.9 Hp engines. Just one thing you are incorrect in where you are measuring the length of the shaft. The measurement starts from the cavitation plate directly above the propellor, from what I see you are measuring from the lower fin above the cavitation plate. Using your measurement will put the caviation plate about 3-4'' below the bottom of the boat and affect the planing characteristics & steering of the boat. The cavitiation plate should ideally be flush with the bottom of the boat but no more than a 1/2" variation up or down.

[@Michaelsbackyardmarina]

yep, thanks for watching. know all about the measurement, have a good holiday.

[@ddennerll]

Thanks for making this. Now feel like I could open one of these up and work on it myself.

[@douglasgallipeau6582]

Shaft length is measured from where the clamp meets the transom to the bottom of the anticavatation plate just above the prop, not where you showed it.

[@Michaelsbackyardmarina]

You are correct.

[@buddyg1408]

Anti cativaton plate

[@buddyg1408]

@Russ Gallagher oops I got it backwards it's the anti ventilation plate

[@michaelbowman5396]

9.9 is an above average Johnson. Im restoring an old 1958 Evinrude 18hp. This video was a huge help! Thanks M8!

[@jayeagle8363]

I have a 97 suzuki 9.9 with the 15hp setup on a 12' fiberglass johnboat popular mod around here .🇨🇦✌

[@Michaelsbackyardmarina]

Very nice.

[@MitzvosGolem1]

On these motors under power head there is a rubber grommet on copper water pipe from water pump. Many swell closed in salt water. Motors would overheat. Clean around grommet and put anti corrosion grease on aluminium. Did dozens at dealership 7.5-15 same motors. Good motors

[@danzawraith8104]

Hey mate can I pick your brain? I have a 15hp that I cant find anything about online. my model number is AJ15BACUD Cheers.

[@MitzvosGolem1]

@@danzawraith8104 sure what's wrong?

[@douglaseblankenship3226]

I'm learning a lot from you ,thanks for all videos

[@kylebarcomb6192]

There awsome motors I had one and it always started right up 2 pull after sat all winter

[@Michaelsbackyardmarina]

they are reliable, thanks for watching

[@richardardolino5513]

Converting a 9.9 OMC to a 15hp but keeping the 9.9 cowl was fairly common in New Jersey where many fresh water lakes are legally limited to 10 hp. At some point the newer 9.9 motors were changed and unable to just change carb to convert to 15 hp.

[@Michaelsbackyardmarina]

you are correct, thanks for watching

[@zuestoots5176]

Anymore, if you work on carbed engines, go on amazon and order a wide band o2 sensor and gauge for like 50 bucks.. the best way to tune a carb is actually being able to see the fuel ratio out the back door. You can "Tune by ear" and get sorta close but not as close as actually seeing the AFR's Pick up a couple horsepower and/or tune for economy. Easier too. you dont need to run plug checks I've also seen the Johnson 15s make around 30hp with some intake and exhaust work. I would also like to recommend open your plug gap to .046. 6 over recommended seems to make a little better power on almost every engine. those flat plugs are complete garbage. Hell anything with more than 1 electrode is garbage.

[@ct1762]

02 sensors and carb synch tools like that are only for 4 strokes . no way are you able to get 30hp out of these without some MAJOR port, carb, exhaust and head work. even then i'm skeptical.

[@bradfordpalmer2298]

30mph on a Gheenoe.

[@billm8633]

When you pulled the carburetor you said the screw on the cam follower was for 'idle' adjustment which is wrong. It is for "synchronizing" how far advanced the timing is when the butterfly in the carb begins to open. The idle adjustment stop should be on the outside of the motor by the throttle tower/back end of tiller mount area.

[@Michaelsbackyardmarina]

You are correct, this video is over two years old much more has been learned since then, thanks for watching

[@billm8633]

@@Michaelsbackyardmarina Yeah, but people as recently as half that have replied and who knows how many have not, but have trusted your 'mistake'? Perhaps, if possible, to pin this reply string as an addendum instead?

[@whotknots]

I have a 1981 35 horse still mounted on the boat it was sold on new and it goes like a rocket!~

[@terryallen1467]

Mike I really enjoyed the video of you working on this motor I sent you another request of information and I hope you answer but thanks for being online I will continue watching thank you

[@Michaelsbackyardmarina]

Thanks for watching. Much appreciated

[@jeffhenson1994]

you know this is a great video about outboards

[@borderreiver1806]

In our region ,we have hp restrictions on many lakes, often 9.9 or under.. so .. cowl off of 9.9 on 15hp usuually works ok ..unless the Conservation officer checks the motor tag..

[@Michaelsbackyardmarina]

That could certainly happen. Thanks for watching

[@POL3INAROW]

Just a heads up, when you were discussing where to measure from mounting on the boat, you referenced the wrong plate for being even with the bottom of the hull. The cavitation plate directly above the prop shaft is the plate to be even with the bottom of the boat.

[@Michaelsbackyardmarina]

Yeppers, you are correct.

[@kerrypitt9789]

I can't find part two to make a comment. I wasn't going to subscribe to you just because I subscribe to so many already, but darned if you aren't such an easy guy to listen to and you know your stuff. The other thing I like about old motors is the smell of 2 stroke mixed fuel exhaust. It brings back so many memories of past trips Oh! I found part two on my television just not on my phone.

[@Michaelsbackyardmarina]

Hey thanks for watching. Glad you found part 2

[@stevenlein4772]

In the early 80s my second outboard motor was a 9.9 Johnson in green and white. My cousin an outboard mechanic told me about this trick. It ended up on my buddy's home built hydroplane.

[@dandahermitseals5582]

If you wet the durface beforebyou apply the Vomet and let it sit undisturbed the blesch will go to work. Im 80 and been resurecting ild machines since I was a kid.

[@Michaelsbackyardmarina]

I just may have to give that a try, thanks for watching

[@jimfox4707]

Back in day you could have a 15 from a 9.9 by changing the carburetor to 15 hp size. The engines in each series could lower or elevated by changing carburetors to each hp. 9.9 to 18 was one. 25 to 45?? 55 to up.

[@boatbeard7767]

Always remember that to get the extra power the engine must rev higher, the exhaust tube and spark advance must be swapped over for the tuning to allow the additional revs. The 9.9 is actually better at lower revs and idles much better and otherwise makes the same power to 5,500 rpm - the uprated p[ower comes from the power head revving out to 7,000 rpm at WOT. Because the 9.9 is an engine rated to rev out past 7,000 rpm it is virtually unburstable at 5,500 and loves running WOT all day.

[@danm.243]

Happy I found your video, I think it confirmed what I was suspecting about my 60hp of the same generation (1993). I had noticed the owners manual shows the 60hp and 70hp have the same displacement and I thought it must be pretty easy to convert the 60 to 70 if the block was the same. I wonder if anyone has done the conversion for that motor and if its the same parts to change (carburetor and reed plate spacers).

[@saenole66]

Very interesting video. I will enjoy all of your future presentations.

[@Michaelsbackyardmarina]

Glad to hear that!

[@petelynch6350]

I'm sure by now you realized the difference in the shift shaft in this model was in the lower unit. I've done many of these and you only change driveshaft shift shaft and water tube. No need to drop shift shaft from powerhead

[@Michaelsbackyardmarina]

you are correct. and I have realized it for sure.

[@ronaldnelson7204]

I don,t know if you saw my comment before - But those engine,s have a problem with the water tube grommet at the power head it petrude,s up into the block and closes off the water flow after the motor warms up and starts blowing steam. It needs to be replaced. I am a marine mechanic who originally discovered the problem it shows in salt water sooner. There is a service bulletin about the problem.

[@Michaelsbackyardmarina]

Yes I did see your note. Thanks for watching and commenting

[@dbcooper692]

I have found strait bleach works very well out of a spray bottle for cleaning my 1974 Johnson Seahorse 7and one-half HP. when it gets really dirty.

[@dbcooper692]

I should have said the outside of the motor, only the white painted part

[@Michaelsbackyardmarina]

I will give that a try.

[@mattp9029]

My impeller would not slide off either. The shaft was caked with old grease that had hardened. Had to use a brash brush and carb cleaner to get it off.

[@RichieRouge206]

Just subscribed from the UK. Really like your easy presenting style, and very interesting to follow. I want to find another one of these outboards and get it in the water.

[@Michaelsbackyardmarina]

Welcome aboard!

[@ronstewart5657]

Enjoyed the video and found it very helpful.

[@Michaelsbackyardmarina]

Glad to hear it!

[@coburnlowman]

During collage I would work at a lake marina doing water pumps and such. There was a full time mechanic there that kept calling the lower unit a "'( FOOT)"' the owner told him that if he called it a "'(FOOT)"' again in front of a costumer that he was gonna punch him in the mouth , and that he didn't wanna be noted as a place that hired idiots that were inbred. When I go get parts at my local parts marina and the customer leaves the people behind the counter will make fun of the term "'(FOOT)"'

[@Michaelsbackyardmarina]

is there a point to your comment. Foot, gear box, transmission. Does it really matter.

[@Michaelsbackyardmarina]

Also didn't Mercury come out with an outboard with a larger gear box and they called it the big foot. Most likely where that term came from. Not all tissues are Kleenex. Just how some things come about.

[@fishhuntadventure]

Well using ‘foot’ as a name for lower unit is a lot like saying your motor turns over but it won’t crank. Just bad terminology even if it’s a regional norm. Big Foot harkens to the large biped that roams the north woods.

[@Michaelsbackyardmarina]

Hey throw all the punches you want. thanks for watching

[@Michaelsbackyardmarina]

it's nothing like that but thanks for watching

[@whitetail54]

A lot of good information here Thanks for sharing!

[@Michaelsbackyardmarina]

Glad it was helpful!

[@nathanaelallcock7040]

Hey brother, I just recently got a 1985 9.9 Johnson outboard short shaft motor and I think the thermostat is stuck closed cause it’s not spitting water like it supposed to and it gets hot really quickly, so I shut it down. I’m not sure if it’s the thermostat or the water pump. After this video I will be taking the lower unit apart and checking the water pump. Any input or ideas would be greatly appreciated, thanks Nathan

[@JohnSmith-yv6eq]

How did the replacement of the water pump impellor go?

[@mrtyreus0]

Had one of those on a little 12 ft Sea Nymph. No wonder it was so fast! Always seemed hot for only 9.9

[@marvinbyrom1491]

You can have a "skeg" that looks like a "scag", but not vice-versa. Just saying...keep up the fine work!

[@Michaelsbackyardmarina]

For sure and will do.

[@NovaNinja_]

I wish it was as simple as that nowadays... I have a 15hp 4 stroke Suzuki. Identical to the 20hp except they put a restrictor plate behind the intake, and the timing is different. Only way to step it up is to change the computer

[@bigdiddyb]

Best video instruction out there... well done and I just suscribed. Knowledge tips are excellent too.

[@Michaelsbackyardmarina]

Awesome, thank you!

[@corydunaway]

I have the same engine. Great outboards

[@Michaelsbackyardmarina]

Yes they are!

[@jamescompanion4001]

Good too figure that out . Why won't it re-up unless it's in gear ? In the barrel of water?

[@Michaelsbackyardmarina]

It had a limiter to keep you from over revving the engine

[@jonhutchens9770]

I've had many disappointments with professional mechanics.

[@MegaJessiejames]

Do you have a flywheel nut a can’t find one anywhere. I watch your videos all the time. Thanks for what you do.

[@Michaelsbackyardmarina]

I don't have any spares. Do a google search and you will find plenty. Thanks for watching

[@LewisMowersandBoats]

Great job brother 👏

[@samdittmar5142]

I put a 15 carb on mine and it hauls ass now

[@camstager4455]

Did the same thing. Really helps a tinny with two or three people in it. Fun to beat all the 9.9s on the lake too

[@samdittmar5142]

Cam Stager I use to not be able to plane my 12 ft fiberglass boat on plane with 3 people, but now it hops right up with 3 people coolers and gear

[@ct1762]

@@camstager4455 what year is yours? its more than just a carb, accept for i believe the 79-82' motors. the rest have different reeds, exhaust tuner and some of the later ones (1992 i think) had different porting and timing.

[@camstager4455]

@@ct1762 mine is a 1982. yes the conversion is i think 15hp carb, a shim somewhere for reeds?? and a 15hp exhaust tuner. Did this probably 6years ago. Did them all as a winter project.

[@tntpfs]

The purpose to a 9.9, in Canada, anyway, is that 10hp and above requires Federal Government registration, with numbers on the bow. 9.9 or below don't require this

[@samhunt9380]

Dirty after coming out of the shop having had a $360 service. It should be spotless....

[@Michaelsbackyardmarina]

you would think so.

[@craigkaschan4822]

A 9.9 is the same size / weight and displacement. Only difference is carby and kw magneto pushes out. According to brochures on evinrude and Johnson. The cavitation plate needs to be about an inch below the keel actually.

[@ct1762]

it depends on the year, but most of the differences are bigger exhaust tuner, reeds and carb.

[@seau2007]

Dad's old motors arrived last week. As memory fades the '57 Johnson 7 1/2 is in poor condition. One cylinder is seized. Darn. The 80 Johnson is actually a 6hp. Darn again. I remembered it to be a 9,9. Getting old. I probably will dispose of that. The '57 I would like to resurrect for nostalgia remembering when he purchased it new. I was 8. Can I still get parts?

[@Michaelsbackyardmarina]

You can still find parts. Don't just throw away the 6hp. It still has good parts I'm sure.

[@bdphourde]

I don't remember you saying how the 9.9 became a 15. You did differentiate the two by saying the 15 had a Baer carburetor, but you didn't say that this one had it. How could that happen at the factory? Could it have been a switch by the bumblemech who worked on it trying to find another carb to make it run rather than to fix the one that was on it?

[@silvialindemann6139]

Mike I have a 69 Johnson 20 HP Johnson that I recently bought. It is very clean and runs like a champ in a barrel. When I put it on my boat and put it under load it kept jumping out of gear. I can't find anyone to look at it. Any ideas on what that could be. I don't feel comfortable just jumping in and trying to diagnose it, but If I had an idea of what it likely is that could give me a starting point and I kind of knew what I am getting into, I might take the plunge. Thanks, Paul

[@graycue]

Nice video, I learned a lot. Thanks...

[@Michaelsbackyardmarina]

Glad it was helpful!

[@chuckstyes3196]

9.9 and 15 has the same carb the diff is the size of roller on the linkage. the 9.9 has a smaller roller thus not opening the throttle as far, keeping the rpms lower and hp down to 9.9. this unit looks like it has the 15 hp roller on it. ;)

[@dennisfromm2235]

Well as long S they due work you can clean up the old plugs and save for emergency

[@jaybud3646]

Only difference between a 9.9 and 15 is on a 9.9 there is a restrictor plate between the carb and motor to reduce air flow and cut power.

[@Michaelsbackyardmarina]

not on this year. It's a larger bore carb. no restrictor plate.

[@dandahermitseals5582]

Wow great tip about spacer!!! Didn't know How you change?? Dandahrrmit

[@Michaelsbackyardmarina]

Glad it helped, thanks for watching

[@bookooc5605]

Thanks for these videos. I bought a little skiff a few years ago that has a 15hp Evinrude, of the same vintage as yours. I believe they are the same engine, just blue instead of white. Your videos will help me in getting it running again. Thanks again.

[@sims2bavaroTd]

Great video thanks so much

[@Michaelsbackyardmarina]

Glad you enjoyed it

[@georgegard3570]

I have a 15HP Evinrude that uses a 100 to 1 oil mix and had a friend that was mixing old school 50 to 1 mix for his motor, ran much better on the proper mix. Pay att. to detail.

[@YT__TR3WAY]

What is the link to those plugs you put in that motor

[@RichieRouge206]

We had a 15hp with the same decals and that was new in 1989. To be fair the 9.9 and 15 are identical in pretty much every way. Great video

[@Michaelsbackyardmarina]

Only difference is the carb for a specific range of years.

[@eamh2002]

These smaller johnsons/evinrudes look kind of weird with the small powerhead and big lower case :D Looks like the case is bigger than my 15hp honda. And not hating on OMC, I have a 4hp 1984 seahorse too, awesome motor for the weight to power ratio :)

[@myCloudWatcher]

I had one from that same era. Back then MANY lakes had a "Less than 10 hp" rule. So 9.9 hp sold fast. My unit was a 15 with a 9.9 "cover". You may have asked why 9.9 and not 10?

[@Michaelsbackyardmarina]

only engineers have the answer to that one.

[@JohnSmith-yv6eq]

@@Michaelsbackyardmarina That "rule re 10HP limit... 9.9HP is under 10HP so we must be "regulation"...right?

[@francesnieznay6623]

That screw on the roller is for syncing the mag timing to the take up of the throttle,there should be a line on the mag ramp that should just move the carb linkage as they cross paths. thanks

[@kypackerfan4-12-15]

A top end performance tip: scratch marks where the ramp is currently assembled, loosen ramp screw(s) and tap the ramp a tiny bit (1/64" at a time) and advance the ramp into the roller. Test after each movement to be sure you didn't over advance. This also needs to be done when the roller and ramp shows signs of long term use wear reducing the originally designed advance.

[@timothyknutsen5212]

I had a 3.5 Johnson, I know a secret, if you can call it that. I believe my 3.5 was a Ted Williams signature series.

[@GreasyStool]

Got a 89 model of that 15 I need a 9.9 cover! LOL!

[@Michaelsbackyardmarina]

I don't but thanks for asking and watching

[@smokeskull]

The engine block porting is different between the 9.9 and 15hp motor. Not just the carburetor

[@Michaelsbackyardmarina]

Not on the years 1974-1978 it’s just the carburetor