Evinrude Johnson 2 cyl 40,48,50 & 60 HP

[ACAMS]

Does anybody here modify these motors?

I have heard several tricks, but would like to know details, maybe even send powerhead off.

Main question is would tearing the motor down and "porting" the intake and exhaust area help?

Heard there was a water crossover passage that should be blocked to release a few more HP.

I will be using an 84 model 60HP powerhead.

[Mark Poole ModVP]

I am sure someone with experience modding these engines will chime in with some details. All of the OMC 2 cyl. and 3 cyl. looper engines respond well to squaring and raising of the exhaust ports as well as shaving the head for more compression. I know on the 3 cyl. models some moderate exhaust port work and getting the compression up around 180 to 190 would made a big increase in performance. "Power Porting" the OMC loopers would make a nice increase also.

[ultrafast]

Find a set of the big bore carbs, I have some. Jet to run with out the airbox. Open up the cowl in the rear- big restriction. . Plastic reeds, cut the head. Finger porting helps. Be careful moving the exhaust ports too much. . You can kill the bottom end quick. Dry stack the exhaust and remove the can. Is it on a light boat. Go on ******************** . there are some real talented people on there. One guy has an expansion chamber set up? I will tell you though, you would be ahead to build a 3 cyl.

[moparman]

just curious as to which year and model the bigbore carbs were on ?

[thornl01]

Just find a set of 60 hp 2 cyl carbs or get 2 from a 3 cyl 70/75.

Tons of mods are available for these engines :cool: ie..... behind the liner porting.( look for sleeves/blocks w/o exhaust relief holes ( sleeves come out very easy) 20 mins @ 350 deg & sleeves will almost fall out. just look at things now, it will come to you what it needs. Find a set of early 60 hp pistons & you will see the difference. Cut head to 165-185 cranking comp. Take 2-3 deg timing out. expansion chamber on these engines WILL wake them UP !!

[ACAMS]

Me too!!!

I have several of these motors, and several 3 cyl stingers, but this is going on a 14' flat bottom jon boat and I just want 55 to 60 HP at the prop.

I will be using a 1991 40hp short shaft mid and lower with a 1984 60hp powerhead and feel I will not have much more than 40 - 50 at the prop without small mods.

I will also need it to idle and low RPM real smooth for running lines in the river, so I was hoping to not have to use aftermarket reeds.

I have a machine shop and can mill the head for extra compression and I ALWAYS run super in my motors.

Ultrafast, you got filtered ... can you PM me the link, or code it

THANKS.


EDIT .... I got ninja'ed .... If I do a little port relief will 77 Stinger 75hp carbs help me, or hurt me?

[scc82]

Why not put reeds in it. It will make it run better and much smother at low rpms. We make great reeds for that motor and almost every other 2 stroke around. I've installed literally thousands of reeds in outboards and ALL of them run smother and idle better. Courious to your reasoning behind that?

stan Carson,

[ACAMS]

Well, actually the only 2 strokes with reeds I have seen idled like a top fuel dragster ..... if you have reeds for this motor that will improve the performance and still idle good please PM me so I can order them.

[scc82]

CCMS. 800 329 2725. Call tonight or in morning and we can talk about your needs. Yes we have the reeds in stock. Cheep performance and safety for your motor. Will idle better burn less fuel accelerate harder and may even see some top end gains. We can also help you out with your other mods you are considering. Although your biggest gain in performance will likely come from proper setup. Happy to help any way I can, and merry Christmas.

Stan Carson.

[ACAMS]

Find a set of the big bore carbs, I have some. Jet to run with out the airbox. Open up the cowl in the rear- big restriction. . Plastic reeds, cut the head. Finger porting helps. Be careful moving the exhaust ports too much. . You can kill the bottom end quick. Dry stack the exhaust and remove the can. Is it on a light boat. Go on ******************** . there are some real talented people on there. One guy has an expansion chamber set up? I will tell you though, you would be ahead to build a 3 cyl.


What do you mean "Dry stack the exhaust and remove the can."

[thornl01]

When using the 48 mid, you may want to check the inner pipe (tuner) as the 48's pipe is very restrictive. Biggest thing on this engine is to NOT LUG the engine, prop it to turn on the top side. These engines like to breathe. Also, get some heat into the engine, Don't run it too cold.

[smokin'joe]

Does anybody here modify these motors?

I have heard several tricks, but would like to know details, maybe even send powerhead off.

Main question is would tearing the motor down and "porting" the intake and exhaust area help?

Heard there was a water crossover passage that should be blocked to release a few more HP.

I will be using an 84 model 60HP powerhead.


The xxx100 and xxx207 blocks/powerheads are used in 45SS class racing. These powerheads appear on motors from 40-60 hp. The 60 hp shortshaft model with small gearcase was discontinued in 1984, was used in SD and DP class racing. I have many blocks from many different hp motors and all are the same. The xxx207 block was a lost foam casting and has a slight intake restriction. So far as I know at this point, the only differences in 40-60 hp motors are high speed jets, heads and powerpacks on the ropestart commercial models. In 45SS racing modifications are not allowed, the motors can be blueprinted. The biggest gain is from resleeving, lining up the sleeves so that the intake passages in the block are not partially blocked. Second is milling and decking, very little is required to get 170-180 psi (more than that hurts performance). Here's the cheap way to do it for river racers: grind the sleeves to get rid of the intake passage blockage, get rid of all sharp edges where the gas mixture flows into the intake ports, and mill the head .065-.070", not more. On commercial tiller handle models (40, 45 hp, e.g.) the powerpack is rev-limited to 5850 RPM and must be changed. The carbs seem to be the same on all models (tuners too) but the low hp models are jetted very lean. Run 56D jets (standard in 1983 60 hp) and increase jet size with weather to keep the plugs wet (dry electrodes are a danger signal). and run Evinrude oil at 25:1. I prefer XD100 synthetic, and run 98 octane gas to avoid detonation although many 45SS drivers run pump 93 octane. Most hobby engineers ruin a powerhead by changing the port timing. I have a 1988 45 hp tiller handle shortshaft commercial model on an Allison EP-15 that I use to break in the 45SS powerheads, simply unbolt the (actually 60hp) fishing powerhead and bolt on the racing powerhead. I have available some preperly reworked Jim Booe castings (12 1/2x23) that run well if you have a 1980-83 shortshaft 60 hp model. The same props are run in SST60, but I set a different pitch distribution in that case. We break in the powerheads long and at low RPM with a thermostat and poppet valve, then remove the poppet valve and thermostat afterward. You do not want the motor to run hot. Water flow direction is reversed in the 45SS racing mid-section compared with the standard mid-section, so if you install both a thermostat and poppet valve in the former for break in yopu'll burn up the motor, no water reaches the powerhead in that case.

mccauleyandson.com

[1FASTLASER]

That's a lot of knowledge right there....and experience. I always wondered about these midrange motors

[MODIFIEDOUTBOARD]

The 60/50 Cylinder head can be milled to 45spec 0.515" deep, stock is approx 0.560" worth about 5 hp and will run on 93 octane pump gas.
You can go up on timining , the 60hp twins ran 21 deg from factory.

Carbs are 1.5" throat x 1.25" venturi same as 75 triple an sst 60. you can remove the factory air box from carbs and pick up about 200 rpms on top end with noticable loss of 3500-4000 midrange power. Tim Kurtz has velocity stacks and they will help top end if your not over proped. will need to go up a step or two on main jets. Boysen makes reeds for the 50 and 45ss.

a 45 style tuner can be made to adapt and replace inner exhaust. I would go longer than 45ss spec to not loose bottom/mid tourque.
also can re-route water in conjunction with tuner mod to feed engine from bottom up and get water to be about 140 deg F under WOT.

Bobs Machine makes a nosecone/low water pick up for the gearcase.

run more oil OMC recomended 25:1 for the 45ss.

[OMCStratos]

What rpms do you run, MODIFIEDOUTBOARD?

[ultrafast]

i have 2 sets of the big carbs if you need them

[Superbender]

used to run mine @7000.all good info try and find one of those xxx100 blocks always worked good for us.

[MODIFIEDOUTBOARD]

45SS w/1:1 LU 7,200 - 7,600rpm , modified for racing 96mph @ 8,200 , the Kamo Viper 7,200 rpms set by port timing and pipe.

put up pics of boat.................. The vid is of the late Brandt Hilsen driving my friend John Runne built 13' hydro # 2Z natural wood finish with my Reverse Engineered 45ss to Recreational Watercraft engine specs (Yamaha SuperJet) turning 8200 rpms.

I drove all night and made it in time to interupt the drivers meeting and talk him into entering it in Formula E Hydro Race against modified 75hp OMC Triples for the first time without testing. He held his own for two laps driving really tight to inside like his normal class 30 mph slower would. point and shoot out of turn with
http://youtu.be/Siyx5H9RQzMphenomanal acceleration! though not enough to compensate for sweeping turns wide like them rocketships.

[vtecman]

So with orifices (jets) whats larger 50D or 60D?

[vtecman]

I tried rebuilt 70hp carbs on my setup, didn't want to run below 1800 rpm acted like it wasnt getting fuel.

[brogreg]

I have a 1985 55 hp commercial johnson i am running on a dux inflatable
i originally ran a 2001 30 hp yamaha
the 55's compression is 115 and 120
i am only getting 1 mph more out of the 55 than i was with the 30
i have found the sweet spot for engine height and prop size
i have noticed that other hp johnsons with the same reeds and manifold have a spacer between the reeds and the stop plate which i'm assuming allows the reeds to open up a little more and allow it to breath better does anyone know if this would help
any of these posts above pertain to the 1985 55hp commercial

[OMCStratos]

Not sure, but you should bump up that compression from where it's at right now. My 50 has 150psi on both cylinders. The yamaha 3cyls are fast. I wouldn't doubt a yamaha 40 being faster than the OMC or even a 30 yamaha. Gear ratio on the 2 cyl OMC's and larger gearcase size don't help.

[brogreg]

i am also running the stock rev limiter i believe it's 5800 cd2
would you recomend changing to a non limiting cd2 i believe the 1986 55 hp commercial used it

[powerabout]

Acams
if you do mod one make sure you use new pistons and later style rods other wise over 6000 they go bang.
( early 80's and on had the new parts)

[brogreg]

Acams
if you do mod one make sure you use new pistons and later style rods other wise over 6000 they go bang.
( early 80's and on had the new parts)
with it being an 85 would those be the later style rods and pistons that your referring to
or should i use new pistons no matter what
i was thinking i should at least use the maxrules rebuild kit before i do anything else
if the cylinder walls look ok i will stay with the stock piston size

[brogreg]

Not sure, but you should bump up that compression from where it's at right now. My 50 has 150psi on both cylinders. The yamaha 3cyls are fast. I wouldn't doubt a yamaha 40 being faster than the OMC or even a 30 yamaha. Gear ratio on the 2 cyl OMC's and larger gearcase size don't help.
is 150psi from head work

[MODIFIEDOUTBOARD]

with it being an 85 would those be the later style rods and pistons that your referring to
or should i use new pistons no matter what
i was thinking i should at least use the maxrules rebuild kit before i do anything else
if the cylinder walls look ok i will stay with the stock piston size

before dissasembly note where Piston Skirt cut outs are in realation to transfer port entry windows at bdc.
the newer pistons require machinig in that area to unshroud transfer port entries. Yes it makes a difference.

[MODIFIEDOUTBOARD]

match skirt cut outs, send pistons, pins & rings to 300 below for cryo, send to swain tech and have anodized surfaces removed everywhere except in ring grooves and wrist pin bores (removing anodize under piston top will aid in dissapating heat) have thermal barrier coted on top and skirts coated "heavy" on sides, bore and hone to wiseco specs, check ring gap and they will last a whole lot longer.

[brogreg]

had never heard of the cryo process but that and the anodizing removal seem to be the way to go after a little research

along with cutting out the piston
i think i have a plan
Thanks

[ChrisCarsonMarine]

i would send my pistons to Bud Conner, (hstream1) at east coast powdercoating to get coated. i had a long discussion with him regarding some 90 yamaha pistons burning holes right through them after a couple bottles of spray. i will not try to explain it, Bud can. but it all made good sence. he also does a low fiction piston skirt coating that is real nice. he is great to work with and knows his stuff. see what he has to say.jmo!!
east coast powdercoating 757-544-1787 Bud Conner

Stan Carson,

[MODIFIEDOUTBOARD]

cryo process makes it possible to spin a 45ss above 7,800 with reliability especiall the rods

[MODIFIEDOUTBOARD]

http://www.youtube.com/watch?v=gnqr7C2jcuY

a 45ss by yours truly on 10' baby cigarette in US Virgin Isles...............

[phillnjack]

Not exactly sure what the original poster wants
if he has a 8460hp powerhead he is already where he wants to be. 1984 is 60hp at the prop so he already has the big bore carbs and the tuner and the head work done by omc.
just put the head on the shortshaft mid and gearbox job done.
those 1984 60hp 2 cylinder engines were a blast and would kick 60 at the prop.
best thing to do is run it and see what it does then think about mods if the engine needs them.
its ok to go nuts for another 10hp on that motor but it wont last very long once he gets revving too high.

from his original post I don't think he wants a top end superfast race motor that will last about 5 hours if he is lucky before another teardown.
if he does then all the info is above, apart from the prop, that wont work on his john boat.

[MODIFIEDOUTBOARD]

https://www.youtube.com/watch?v=KzgW-9zoZA4&feature=youtu.bethou speakest of things which ye knowest not

[phillnjack]

and who was that aimed at ?
if me then go read your first posting.


phill

[OMCStratos]

thou speakest of things which ye knowest not


and who was that aimed at ?
if me then go read your first posting.


phill

Yeah, you phill, you've only been banned multiple times on other forums for being a troll. Please don't stir anything up here.

[Stumpalump]

Bump. I'm fooling with an 85 Johnson 60 2 cyl on a 16 Valco aluminum boat. I've never had an engine or boat respond so well to tune and setup. It did 26 mph when I bought it and does 37.5 by just fooling with the basics. I just did the bottom with Scotchbrite, sanded out a few nicks and weld buggers. I have no doubt I'll hit 38 today. My timing light crapped out. I'm going to bump the timing a quarter turn at a time in between WOT runs to see if it helps. Good plan or not? Will anybody take a WAG ( wild azz guess) at how many degrees of timing 1 full turn will change?

[powerabout]

too much timing will slow you down at wot
raise the engine up as far as you can go, thats where cheap and easy speed comes from
you also need to know the rpm its doing

[Stumpalump]

too much timing will slow you down at wot
raise the engine up as far as you can go, thats where cheap and easy speed comes from
you also need to know the rpm its doing Engine was set so high when I got it that it would not take much trim with the pin before cavitating. I added power trim and had the same problem so I dropped height to gain 2 mph :) Now the cavitation plate is even with the bottom. I calibrated the tach to dead nuts with a lab grade tach and it reads 5800 with a 17p 3 blade aluminum prop. It's running great but I'd like to see 6000 then I may swap props to a ??? Are fancy reeds only good for low end grunt?

[powerabout]

Engine was set so high when I got it that it would not take much trim with the pin before cavitating. I added power trim and had the same problem so I dropped height to gain 2 mph :) Now the cavitation plate is even with the bottom. I calibrated the tach to dead nuts with a lab grade tach and it reads 5800 with a 17p 3 blade aluminum prop. It's running great but I'd like to see 6000 then I may swap props to a ??? Are fancy reeds only good for low end grunt?

All the different brands of reeds do one thing, when they break the bits dont kill your engine.
Where they effect performance is sometimes different, some even make idle better.
You should at least pull yours to inspect to see if any are open at rest and remove them and lap the blocks.
If you need to have your gearbox cav plate level to allow trim either boat too heavy or too heavy forward ( CoG wrong)

[Stumpalump]

If you need to have your gearbox cav plate level to allow trim either boat too heavy or too heavy forward ( CoG wrong)
lol. It's heavy forward alright! Out of all the boats I've owned this is not a performance hull by any stretch. It's designed for beach launching and running surf in Baja. You can't tell from the pict but it's got a huge steep V bow and as you can see a flat bottom. The seat is on the rear bench top and fuel and battery behind it. 10lbs of gear in the middle seat and nothing up front. It's just a hard hull to air out and fly but when it does it's nothing but that flat bottom. I think that bottom is why I had to raise it. I've had a big block Bravo outdrive 20' Concord but I'm having as much fun with this beater.

300523

[Stumpalump]

300526

[Stumpalump]

Results of fooling with timing:
I set the trim so it would run a stable 33.0 mph and never touched it. I decreased the timing 1/2 turn and speed dropped to 29.5 and it felt sluggish. I raised it 1/2 turn and went up to 33.5. A half turn more and it stayed the same. Just 1/4 turn advanced still gave me 33.5. Best I could get top end was 37.7 with the wind and 36.3 up wind on a hot muggy day, full tank and the dog. That's the best this boat has ever run. Is there anything else I could do to tweak the little 60? I do have a spare motor and both blocks end with #100 but neither have ever been opened.

[95cummins5.9]

This thread talked me into joining. Nice site guys. Does anybody have a part number for the big bore carbs. Thanks for all the great information I'm this thread.

[powerabout]

You cant buy a carb body so there are dozens of part numbers to suit every different jet size combo used on all the models.
Just measure the venturi

[95cummins5.9]

will probably be surfacing my head tomorrow (work at a machine shop). So just for clarification the 75 carbs won't work so well, but the 70 hp will? Who makes a better set of reeds vs, boyson (spelling) ? Sorry to hi jack the thread. Good to keep all thr info in one spot though.. thanks again.

[powerabout]

75 are the bigger bore as are 70hp ones from the 56ci 3 cyl as are 60 and 55hp 2cyl if that was the highest hp of the 2 cyl in that year

[95cummins5.9]

Thank you. Ordered my reeds today! Mr. Carson is a awesome guy, very helpful.

[brogreg]

which reeds did you end up going with?

[95cummins5.9]

Chris Carson's

[Xpress2830]

Hey guys Bobby here from.Louisiana. I have a 93 40 head milled to 150 psi,ported reed cages,Boyesen reeds, 50 carbs with 55D hs jets & 45D ls jets. I ran 49D ls and plugs stayed too wet and motor.did not idle as good / crisp aa ot should. The 45D seemed to idle a little better. Should I keep goin down in orifice size until I get the correct mix? Any educated help would be greatly appreciated. Please feel free to email me at [email protected]. Thanks, Bobby..

[ACAMS]

Not exactly sure what the original poster wants
if he has a 8460hp powerhead he is already where he wants to be. 1984 is 60hp at the prop so he already has the big bore carbs and the tuner and the head work done by omc.
just put the head on the shortshaft mid and gearbox job done.
those 1984 60hp 2 cylinder engines were a blast and would kick 60 at the prop.
best thing to do is run it and see what it does then think about mods if the engine needs them.
its ok to go nuts for another 10hp on that motor but it wont last very long once he gets revving too high.

from his original post I don't think he wants a top end superfast race motor that will last about 5 hours if he is lucky before another teardown.
if he does then all the info is above, apart from the prop, that wont work on his john boat.

LOL .... I can't believe this topic is still going.

I now have a motor just like this

http://acams.us/ShortStinger/75Hustler.jpg


Going on this boat Xpress 1546

http://acams.us/Xpress/Flat-001.jpg



I am putting the 60 on a Bass Tracker to sell because I still have this pile!

http://acams.us/Xpress/Flat-005.jpg

[smokin'joe]

I'm confused by the discussion. The 3 cyl. 49.9 ci 75 (like the 1975 model shown in the photo) puts out 68 hp at the prop. The corresponding 70 puts out about 63 shp and was labeled '60'. The 45 ci 2 cyl. 60 puts out about 54 shp and was labeled
either 50 (pleasure model) or 55 (commercial model). The later 3 cyl. 56 ci 70 shp puts out about 78 hp at the crank. shp=shaft hp or hp measured at the propshaft.



LOL .... I can't believe this topic is still going.

I now have a motor just like this

http://acams.us/ShortStinger/75Hustler.jpg


Going on this boat Xpress 1546

http://acams.us/Xpress/Flat-001.jpg



I am putting the 60 on a Bass Tracker to sell because I still have this pile!

http://acams.us/Xpress/Flat-005.jpg

[smokin'joe]

Some advice: pull the exhaust manifold. You can unbolt and remove it without pulling the powerhead. You will find that the thin inner exhaust plate is warped. Resurface it on both sides and use new gaskets along with 3M hi-temp. sealer. If you don't, then the likelihood is that the motor will suck water into one or more cyl. on the intake stroke. The least damage that can occur is scored cyl. and pistons. The worst is ruined crank journals and rods. This is the only weakness in the 3 cyl. 49.9 ci motor, the 56 ci 3 cyl. and 45 ci 2 cyl. motors are immune to this disease.


LOL .... I can't believe this topic is still going.

I now have a motor just like this

http://acams.us/ShortStinger/75Hustler.jpg


Going on this boat Xpress 1546

http://acams.us/Xpress/Flat-001.jpg



I am putting the 60 on a Bass Tracker to sell because I still have this pile!

http://acams.us/Xpress/Flat-005.jpg

[ACAMS]

Some advice: pull the exhaust manifold. You can unbolt and remove it without pulling the powerhead. You will find that the thin inner exhaust plate is warped. Resurface it on both sides and use new gaskets along with 3M hi-temp. sealer. If you don't, then the likelihood is that the motor will suck water into one or more cyl. on the intake stroke. The least damage that can occur is scored cyl. and pistons. The worst is ruined crank journals and rods. This is the only weakness in the 3 cyl. 49.9 ci motor, the 56 ci 3 cyl. and 45 ci 2 cyl. motors are immune to this disease.

I have heard that and planning on doing that, and thermostat and, and ....... well my list of gaskets and small parts was $350.00

Motor is laying on the floor till after Christmas .... then I start back on the project.

http://acams.us/Xpress/Flat-004.jpg

[powerabout]

56ci 3cyl and 45ci 2cyl since about 1980 have integral cast side plates so exhaust leak issue eliminated

[olboatman]

Scribed. Great info !! Gary

[phillnjack]

so is this 49 cu in 75 hustler going back on its longshaft mid and big gearcase ?
or do you have the mid and small gearbox of a short shaft for it ?

the 56 cu in motors came out in 1986 that had the different exhaust..

[Shinyboat]

I am sure someone with experience modding these engines will chime in with some details. All of the OMC 2 cyl. and 3 cyl. looper engines respond well to squaring and raising of the exhaust ports as well as shaving the head for more compression. I know on the 3 cyl. models some moderate exhaust port work and getting the compression up around 180 to 190 would made a big increase in performance. "Power Porting" the OMC loopers would make a nice increase also.

I am getting into 50 mods and would like to open up exhaust ports but I’m not sure where they are. I know this is an old thread. Can you post a picture of a parts diagram showing where the exist ports that need opened up are?