77' Johnson 15hp Outboard Powerhead?

[N1NE1]

Hello again everyone, just picked up a 77' johnson outboard tiller motor that has a blown powerhead for $50 that i just couldnt turn away,im debating on whether to part it out or find a powerhead to get it going again.anyone know of the possible years of the powerheads that will fit this motor besides just for 77. its a shortshaft , pullstart ,sea horse motor, its in pretty good condition without rust.your opinions will help alot. thanks again

[N1NE1]

Model# 15r77m

[bktheking]

First off , what's blown. It might be salvageable. If you don't care to repair it ebay has 2 or 3 a week show up, the 9.9 powerhead is the same, swap over the carb and electronics and be done with it. Simple to work on IMO.

Check your pm

[N1NE1]

ALL YEARS FOR THE 9.9-15 ARE THE SAME? i seen a few listed on there but not sure which ones will work, the previous owner rebuilt it and forgot to tighten a bolt and so the bold rattled around inside and cracked a few things. not sure which parts i can reuse if i get a newer year powerhead. i dont want to buy one and have it be worthless to me

[bktheking]

Not all but most 75-76 were mag ignition, 77- 85 were the same, 86 and up the thermostat location changed but will still bolt up. If you stick to 77-85 it's a matter of moving the electronics and fuel pump. The reed plates are said to have spacers on the 79 and up 15's so if you if you get a 9.9 block make sure you order and install the shims for the reed plate, the shims allow for more fuel flow for the 15 carb.

[N1NE1]

thanku very much, looks as of right now im going to have a new project.the whole motor is taken down into sections and boxed up so i think i may possibly do a complete repaint and try to restore everything to make it look new.i'l give it a little time for a 15hp to show up on ebay and go from there. if i have any problems i'l be back here,thanks again

[bktheking]

thanku very much, looks as of right now im going to have a new project.the whole motor is taken down into sections and boxed up so i think i may possibly do a complete repaint and try to restore everything to make it look new.i'l give it a little time for a 15hp to show up on ebay and go from there. if i have any problems i'l be back here,thanks again

Sounds like fun, I'm going to repaint my 76 15 hp this week (hopefully).
A 15 might be harder to find than a 9.9, 10 9.9's were built to every 15, 10:1, just get a 9.9 and do the reed mod, you'll find it will run better anyways as 77 didn't have it either.

[the machinist]

9.9/15hp blocks are basically the same from 1974 thru 1992. Like BKTK says electronics are different. Your 77 should have electronic ignition. And if the electronics are OK, then any block would get you on the way.


To upgrade to a slightly improved version of electronics & thermostat placement, if you could find a complete powerhead with carburetor from 1986 to 92 & make a complete swap.

Many of the sellers on e-Bay are not that informed if you have to try to change electronics & carburetors. But blocks will interchange.

If you have any questions, look at my articles http://www.sschapterpsa.com/rambling...n%209.9_15.htm

[N1NE1]

I Bought An 82' 9.9 Powerhead Thats In Excellent Condition, All Electronics And Everything Else Look Like They Will Line Right Up, Can I Use The Carb And Reed Cage Off My 77'? Or Should I Just Use The 9.9 Cage With The Spacer Off My 15hp, Anything I Should Know?

[bktheking]

I Bought An 82' 9.9 Powerhead Thats In Excellent Condition, All Electronics And Everything Else Look Like They Will Line Right Up, Can I Use The Carb And Reed Cage Off My 77'? Or Should I Just Use The 9.9 Cage With The Spacer Off My 15hp, Anything I Should Know?

They are the same cage, 77 or 82 will work- go with the better condition plate and reeds and remember to tranfer the spacers if you go with 9.9, run the 15 hp carb for sure. Check the small mesh screen on the plate for dirt/oil, clean it out before you install. If the 15hp reeds are good i'd just bolt it up along with the carb.

[N1NE1]

another question,will newer coils work with my 77' electronics.they have the same plug.its a single plug with the 2 orange wires ,theres a set on ebay that lok much better than the set i have for a good price