Early 80's Johnson 30 hp (pic added)

[jerad_s]

I have a motor question for you gear heads. I was boating over the 4th and lost power on my 30 hp Johnson. Got it home and pulled the head off. I found a piece of metal about the size of a nickel and flat as a sheet of paper in the top cylinder. The piston has some small knicks and the cylinder wall and piston have some light scoring. Rings look fine. I then tore off the starboard side (intake?) of the motor and found another metal flake, just a tad bigger in the area where you can see into the crank. My dad says a reed valve went out on me and the smaller piece got into the cylinder and caused the piston damage. I should say that the piston has more scoring than the wall. I only noticed one scratch about 1/2 inch long towards the top of the wall.

I have a friend who is an auto mechanic who thinks we can rip it apart and put the new piston and rings in.

Should I go that route? Should I buy a whole new power head? Can a guy replace the reed valve? Would the repair manual help me out alot? What do I need to know to do this job?

Im thinking Ill stick enough money in the motor to get it running and then send it down the road.

What do you guys think?

 

[ftltony]

Re: Early 80's Johnson 30 hp

Re: Early 80's Johnson 30 hp

If the scratch isn't too deep, and the cylinder can be bored, and you can get the rings, rebuild that sucker!

If you have money burning a hole in your pocket, buy a new power head!

If you have more money than God, Go buy a new motor!

 

[jerad_s]

Re: Early 80's Johnson 30 hp

Re: Early 80's Johnson 30 hp

scratch can be honed out very easy I think.

Another little question, do I need to replace all of the gaskets while I have it torn apart? How much am I looking at for parts ($)?

 

[wbeaton]

Re: Early 80's Johnson 30 hp

Re: Early 80's Johnson 30 hp

Great motor, but not much value in a rebuild if you intend to sell it. You'd probably make more profit by parting it out. I priced out the powerhead seal kit for a 25 hp (same block) last year and I believe the cost was something like $200-250. Add piston, rings, etc. and you have an expensive venture for a motor that is realistically only worth $600-1000 in good running condition. I'd rebuild it and keep it. You won't likely find a decent replacement for the price of a rebuild. That is assuming you have the ability/knowledge to do it yourself. You could, however, look for a good used powerhead and bolt it to your motor. I bought a 1988 Johnson 30 electric start tiller with a rebuilt powerhead, but blown lower unit for $300 a couple years ago. Added a good LU from a 25 hp parts motor with a bad powerhead and presto! I had a new and better motor.

What was your compression like? If its just a blown reed and a couple of minor surface scratches then maybe you don't need a rebuild at all. Reeds are easy enough to replace. You'll have to make sure you have all the pieces from the old reed assembly before you try running it again. Just a thought.

 

[Harker]

Re: Early 80's Johnson 30 hp

Re: Early 80's Johnson 30 hp

rebuilt a 90's 30 hp 2 years ago. The complete gasket kit was about 50 bucks, 2 new pistons were 90 ea including rings. I bought a new in the box block on ebay for 35.00 so it ended up costing 265.00 + some misc gasket adhesive and gel seal. Runs great.

 

[iwombat]

Re: Early 80's Johnson 30 hp

Re: Early 80's Johnson 30 hp

If it's only one or two small scratches you can run it that way for quite some time. Big scratches or lots of little scores need to be dealt with. Can you post some pictures?

 

[wbeaton]

Re: Early 80's Johnson 30 hp

Re: Early 80's Johnson 30 hp

I just ran the gasket set I was looking at and its only $70. The $200-250 must have been my total for parts minus the pistons. Sorry for the misleading info.

 

[jerad_s]

Re: Early 80's Johnson 30 hp

Re: Early 80's Johnson 30 hp

dudes,
I found the problem. I tore off the carb and the plate behind the carb tonight and one of the reed valves is missing two lobes (found one piece in the cylinder and one near the crank). After inspecting the piston again, I doesnt look as bad as I first thought. The scoring is above the rings. My plan now is to put in two new reed valves and put it back together and see if it will run. I never did check the compression on the top cylinder. Maybe I never lost compression, maybe it died because of the reed valve. Im going to cross my fingers and hope I can get it running again.

Ive been searching on the net, but I cant find anywhere that has reed valves for an 85' Johnson 30 hp. Anyone know where I can get one? Is there anything I need to know about putting one in?

 

[jbjennings]

Re: Early 80's Johnson 30 hp (pic added)

From my one experience with bad reeds, if it died after you started slowing down, the reeds are definitely why. If the compression is o.k., I'd just put the new reeds in, making sure i got all the pieces of the old one out of the engine. The only thing I can think of as far as installing them is to be very careful not to bend them in any way. You might also clean the intake surface really well before installing them.
Good luck with it,
JBJ

BTW, Do you have any idea what caused the reed to break? I've never seen that happen before! Pretty scary! I've heard backfires can cause it??!!

 

[rookieboater59]

Re: Early 80's Johnson 30 hp (pic added)

Dude. try going on Craigslist.com in your local area for parts.
I just sold my 85' es 30hp Johnson for 150 bucks ( it had a bad gear/lower unit problem) listing it. There always someone selling or buying usually with private parties invovled; or good ole ebay(not really my cup of tea with all that bidding crap!) Good luck with your search for parts or parts motor.

 

[wbeaton]

Re: Early 80's Johnson 30 hp (pic added)

The reeds come in two assemblies. Since at least one assembly broke I'd replace both. They are about $22 per unit plus $3 for the intake gasket based on a 1984 30 hp (first year of the 30 hp). So you can do this for under $50 new. You need to post what your model number is and we can tell you what part you need. Or you can look it up yourself on the BRP website. Its a great resource and worth bookmarking.

 

[tashasdaddy]

Re: Early 80's Johnson 30 hp (pic added)

all of your parts are available right here. you can do a direct order there.
http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

don't forget the gaskets for the parts you took off.

 

[jerad_s]

Re: Early 80's Johnson 30 hp (pic added)

model # is J30RLCOA, from that I get that it is an 85'. Ive tried a bunch of times now to add the part to my shopping cart from this site and it will not go in there. I click on the part and add to cart, then click on my cart and it isnt there. I need to get this thing ordered so I can put humpdy dumpdy back together again.