Powerhead Swapping

[FUZZYDP]

J4590203 76 200 Johnson powerhead . Want to put on 89 150 R8271842 Evinrude . Any issues?

[omcforever]

Yep,,,,1976 used a different intake manifold. Must use intake from 1989 motor(1976 had a different shift linkage set up vs 1989). Intakes had different type carb mating surfaces and gaskets so that could create a run ability issue as well with different newer style carbs. Have to transfer all carbs/linkage(the choke system was different on the 1976 vs 1989)/electronics/flywheel from 89(35 amp quickstart system if 1989 XP or GT and 1976 use a rectifier system and 9 amp system). Just curious why you want a 1976 high port 200 on a 1989 mid and lower? The 1989 was one of the best and strongest Crossflows made(closer to 165-170 HP). The 76 200 had the same bore and stroke as the 150 just different port timing and bigger carbs.(less bottom end than the 150) You may run into carb re-jetting issues with the 200 powerhead and 150 carbs as well. 1-5/16 vs 1-3/8 throats. 1976 also may have high ring pistons and super high compression heads which is bad with todays fuel. The 1989 was rpm limited to about 5800 rpm/the 1976 200 wasnt but had twin packs vs a single pack on the 1989. Putting a 1976 200 on a 1989 can be done but may have all kinds of issues vs any gains. What you will wind up with is a motor that is rpm limited to 5800(89 electronics) and cant utilize the 200 porting and bigger carbs. Just a motor with less bottom end torque than your 1989 150 and maybe the same top end. Why not just rebuild or replace yours with an identical 150 powerhead? (If yours is blown or worn out)

[omcforever]

You do mean putting a 1976 200 powerhead on a 1989 150 motor,,right? If you are wanting to put a 1989 150 on a 1976 200 just reverse the above items in post #2. Also some of the early motors didnt have recirc system like the 1989 150 so may have issues there as well. The powerheads will interchange either way(but with possible issues).....................I recommend changing with proper powerhead for proper HP and year,,,no issues-no headaches..I have done about every conversion/interchange/adapting/swapping of old crossflows possible and you should not mix and match........... Dont want to create a problem motor.....been there and done that. Not a good swap. Either way. 1976-1978 crossflow 200 powerheads just had too many differences to just drop onto a 1989 150 or visa versa and run properly without some tinkering and tuning. But they worked great for the years intended.

[FUZZYDP]

You do mean putting a 1976 200 powerhead on a 1989 150 motor,,right? If you are wanting to put a 1989 150 on a 1976 200 just reverse the above items in post #2. Also some of the early motors didnt have recirc system like the 1989 150 so may have issues there as well. The powerheads will interchange either way(but with possible issues).....................I recommend changing with proper powerhead for proper HP and year,,,no issues-no headaches..I have done about every conversion/interchange/adapting/swapping of old crossflows possible and you should not mix and match........... Dont want to create a problem motor.....been there and done that. Not a good swap. Either way. 1976-1978 crossflow 200 powerheads just had too many differences to just drop onto a 1989 150 or visa versa and run properly without some tinkering and tuning. But they worked great for the years intended.

Ok I’m a little confused so bare with me. I have a complete running 76 200 powerhead. Want to mount on complete 89 150 once I pull that powerhead. It grenaded💥. Just @ a glance seem very similar. Have title to 89 therefore would like to use if possible. 76 just needs lower unit. No title though. So I would think my issue would be with base plate?

[20DC BULLET]

Either rebuild the "76" lower unit or the "89" powerhead....alot less headaches!! Why not fix both and sell one to recoupe some money or rebuild the better one and part out the other....either way alot easier.

[omcforever]

1976 uses a different style lower than the 1989 and 1989/1976 baseplates are the same but,,,,,,,,1976 intake and carbs wont work on 1989(linkage differences)/1976 used big carbs and non rpm restricted packs. All electronics are different including flywheel. Again, 1976 will bolt on but had too many differences that would cause issues(aggressive porting/big carbs/high compression)-re-read my first 2 posts. Use a 1979 or newer 150 powerhead on your 1989 or rebuild yours. No headaches. Titles dont matter as far as changing powerheads. The title shows the numbers on the motor mount itself. Not the powerhead.

[FUZZYDP]

So 89 lower unit “won’t “ fit on 76 correct? Looks like 79^ for compatibility. The 89 powerhead as it sits has a hole in starboard side by base big enough to put your hand in. There’s no rebuilding it. 76 does not have a lower. ��*♂️

[omcforever]

Looks like 79^ for compatibility.