25hp johnson powerhead removal

[Kajun37]

i picked this motor up last night for $100...looks to be a low hour motor considering the condition under the hood ....was froze up but i managed to get it moving , the bottom cylinder is rusted up,but no scoring! gonna take it apart and get the cylinders honed and put new rings in it and hopefully have a good motor.

can anyone tell me how to remove the last bolt on this powerhead?..there is no way to get a socket or wrench on it....the motor is a 73 or 74 johnson 25hp........

 

[samo_ott]

Re: 25hp johnson powerhead removal

That lower piston and cylinder are quite rusted. I'm surprised you got it freed up. It's a good thing you plan to take it apart as I'd be worried about the bearings and crank being rusted up also. It might have gotten water in it from the looks of it but hopefully you'll be ok.

And what is the model num to get a year?

 

[F_R]

Re: 25hp johnson powerhead removal

I've had a jillion of them apart and don't recall ever having any problem getting that bolt out. Try wedging the thing back a bit on the rubber mounts. Earlier models had a phillips head screw in that location, which was easier.

Good luck. That thing looks like a junker from what is visable in the pictures. I'd be very surprised if the crank and bearings are any good.

 

[Kajun37]

Re: 25hp johnson powerhead removal

i tried wedging it back as far as it will go and i still cant get a socket on it right.. there has got to be a way to get it off...i'm running out of hair to pull out lol

 

[HighTrim]

Re: 25hp johnson powerhead removal

Have you tried a swivel with a thin walled socket?

 

[Kajun37]

Re: 25hp johnson powerhead removal

no..i dont have one...i'll run to autozone and see if they have one

 

[Kajun37]

Re: 25hp johnson powerhead removal

bought a swivel but it didnt work either ...they didnt have a thin walled socket..i cant believe this one bolt is kickin my butt!

 

[jbjennings]

Re: 25hp johnson powerhead removal

Have you tried grinding down the wall on an old cheap socket? A little heat on the surrounding area may help if it's stuck. How about using a good, tight end wrench and putting it on vertically and turning it with a pair of channel locks? I don't recommend that 'cause it is a recipe for stripping it, but I have had that work before. I'm thinking grinding down the wall of an old socket and using that or trying a nice thin-walled snap-on socket would be the best bet. Also, you know that powerhead is toast, right? That powerhead is pretty common though, I believe used for 2 or 3 years at least, so hopefully you'll be able to find a good one. I had to find one myself for an old QD-14 10hp the other day.--much cheaper than a prof. rebuild or new motor. Like F-R said, your crank and other stuff is probably too rusted to rebuild anyway.
Good luck,
JBJ

 

[Kajun37]

Re: 25hp johnson powerhead removal

well i ended up having to drill out the 2 bolts that hold cover at the bottom of the leg...then i was able to detach the whole leg and powerhead from the transom brackets....way too much work for one #$%^ bolt

the crank and piston arms and bearing look fine.. it was only rusted where you seen and that pic made it look alil worst than it was, basically just surface rust on the cyl walls...i'll take some more pics after i let my blood pressure come down to normal levels lol

 

[F_R]

Re: 25hp johnson powerhead removal

I promise you that that isn't the normal procedure, but glad it worked for you.

 

[samo_ott]

Re: 25hp johnson powerhead removal

thats great the insides were ok, it didnt look too good!

 

[Kajun37]

Re: 25hp johnson powerhead removal

yea FR i'm always getting the abnormal one that kicks my butt lol...i had to drill out the 2 bolts on the leg because they were recessed and my sockets would not fit in there.. it needed thin walled sockets and i didnt have any...

well heres the pics.. everything looks ok..cept for one spot on the cylinder wall...has some scattered shallow pitting(marked in red)...gonna bring it to a machine shop this week and see what they say...hopefully i can get away with a good honing and new rings...what do ya think about it?

 

[samo_ott]

Re: 25hp johnson powerhead removal

It certainly looks a lot better then it did! Hope honing will do it, but machine shops have a way of overdoing everything. The rings had lost their sharpness I reckon then?

 

[jbjennings]

Re: 25hp johnson powerhead removal

Wow, CAJUN37---you don't fool around! Already got 'er torn down eh?`
Those are great motors, I'd like to have one just like it myself.. Glad to see it wasn't totally boogered up like I thought. Those first pics looked BAD! It looked to me like that bottom piston was all ground up on top.
Can't wait to hear what happens. I hope you'll show us some pics when you get it back in top notch condition.
JBJ

 

[flabum]

Re: 25hp johnson powerhead removal

I'd go down to your local Napa and get a rigid hone and hone it yourself.... Those pits don't look all that bad and even if they are still vaguely there after honing, I'd just go with a new set of rings and let her fly.

 

[samo_ott]

Re: 25hp johnson powerhead removal

Wow, CAJUN37---you don't fool around! Already got 'er torn down eh?`
Those are great motors, I'd like to have one just like it myself.. Glad to see it wasn't totally boogered up like I thought. Those first pics looked BAD! It looked to me like that bottom piston was all ground up on top.
Can't wait to hear what happens. I hope you'll show us some pics when you get it back in top notch condition.
JBJ

No kidding eh! I wish I had that kind of time on the weekend to work on engines! instead I have a wailing 3 week old!

 

[Kajun37]

Re: 25hp johnson powerhead removal

already?? hehe it took me 2 days to break it down lol but i'm a single man, i'm able to spend the whole weekend in the garage while drinkin beer

jb..if i can get it running i'll post some more pics up and a video, if it runs.. this will be my first rebuild

samo..the rings on the bottom piston were froze in the grooves i had to dig them out piece by piece...the top piston rings looked great.

as for the honing..do ya'll think i should buy a hone and do it myself or bring to a machine shop? ....what kind of hone should i buy?

 

[samo_ott]

Re: 25hp johnson powerhead removal

I hone my own. You can get em at any auto store... The small engines use a brake cylinder hone... then use a slow speed drill... in and out.... cross hatch style...

piece by piece... ugh...

 

[Kajun37]

Re: 25hp johnson powerhead removal

oh geez..called the johnson parts dealer here and he said the ring sets are $40 a piece!!! ...so $80 just to put rings on this dang thing!! and $20 to get it honed at a machine shop......


does anyone know where i can find these rings cheaper? part# 385349

 

[tashasdaddy]

Re: 25hp johnson powerhead removal

i checked a couple of online stores, with shipping they would be more. dealer is a good deal.