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1984 Johnson 4hp Seahorse general informations needed

Spark plug wire to engine ground is the secondary windings in the coils. It must jump a open air gap of at least 1/4 inch brite blue snap on both plug wires. You can do the testing on the ignition just pull the gearbox so not to damage the impeller turning it over out of the water.
 
For some reason I can't look at the previous posts by other forum members. I can only see my posts, Is this because the thread is a couple years old? I was hoping to revisit some of the information offered as it's been a while.
Thanks
 
Well if you were the only fellow that was posting.and I remember you were helping a lot. There are no other posts untill the recent few. Maybe that's what happened, Pity there was a lot of good information.Ah well

i took the lower end off just to check things out as there still seems to be a serious overheating probelm(last trip, smoke melting plastic cowling. etc) It all looked good down there. Impeller still good, pump looked fine.
However I noticed another bad sign of overheating. the black plastic sheathing around the two spark plug leads was roasted (almost charred) where it it passed through the clip that holds them to the head.
Was going over the rest of the engine and I did notice to my slight horror that the carburetor was lose from the &*^*&* powerhead!! Yikes!! Can't be good for the (*&^*& mixture!

is it worth it to pull the head from the engine to check the water jacket, cylinders and pistons?

I'm not doing ignition stuff right now as I have the engine in my apartment/shop....

How hard is it to take the upper cowling/recoil starter off ??
 
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It never hurts to pull the head I recommend a new gasket before you pull the head. I never took a 4hp apart it shouldnt be too difficult to pull the recoil starter. The flywheel may be welded on pretty good get three grade 8 1/4 20 bolts three inches long and use a harmonic balancer puller. Screw the bolts in at least five threads and then crank on the puller until you think the bolts will break. Then lift up hard on the puller and smack on the ram with a hammer.
 
Do not loosen the screw on top of the engine cover. On my 2hp there are four bolts with large screwdriver slots remove those bolts and the recoil should lift right off. Are you using a remote fuel tank?
 
My motor uses a remote tank

Thanks for the tips on removing the recoil starter

the PO gave me dire warnings about taking it off ...mind you he also cut the choke knob in half to remove the lower cowling so I imagine his advice wasn't likely the best

as to overheating my brother was suggesting the carb being loose9and it was move the carb around with your hand loose!) could result in an excessively lean mixture which could've been the cause of the over-heating last time i used th motor on the water.
Does that seem likely
The time before (when it got swamped) it had run for at least 1.5 hours about 3/4 throttle no problems
 
The carb has little do do with overheating Your compression is good is this a salt water motor? If so on the down time get a gasket set and reseal the motor and clean all the cooling circuits real good.
http://www.ebay.com/itm/OMC-0439081...ash=item2ee6bf4346:g:nSsAAOxyRNJSj-Oq&vxp=mtr You shouldnt have to split the crankcase or the intake manifold but pulling the head and exhaust cover will tell you if you need to remove the powerhead?
http://www.marineengine.com/newparts/part_details.php?pnum=OMC0439081
 
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That's a good idea, I could pick up some gasket material
Do you know what type it is?...I guess the old gasket can tell me that,:D
I used to do that with my seagulls. But not the head gasket as it was a copper unit
 
I just use standard gasket material and lightly coat both sides with permatex aviation gasket maker. Just brush a light coat on both sides and dont try and torque the bolts to spec. Good and snug is all thats necessary. The head bolts need to be torqued in a center out pattern to spec. Lightly surface the head on a glass table in a figure 8 pattern with 220 grit until it all shines the same. Do not put anything on the head gasket.
 
Cool! and thanks
There's a couple things I wanted to clarify though

Do you mean coat the head and cylinder mating surfaces with the aviation gasket goo (my dada would have this for sure he used to do all his own airplane maintenance)
or both sides of the gasket?
because at the end you say 'don't put anything on the gasket'

also the head bolts:
initially you say good and snug is adequate but later you say to tighten them from the center out to spec

Sorry for my confusion
 
I did find this article and several more like it. It says that running a two stroke too lean can actually seize an engine due to overheating (and even burn a hole in your piston or cylinder!
I was talking to my family about it this eve and my dad (the airplane/ mech engineer guy) confirmed that

http://www.scienceforums.com/topic/3055-why-does-a-lean-engine-run-hot/

Thought you might be interested
I'm going to look at the head anyway,because then I'll know for sure
 
Running lean will burn up the pistons but not necessarily over heat the motor, your overheating is most likely due to poor water flow through the engine.

Salt water or fresh water?
 
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Okay I get it now, you were talking about all the gaskets
Thanks!

I can't say about the previous owner as I think he was flipping the engine but I have run it in the salt , probably about a half dozen times total
I have also used that saltaway stuff on it and I run it in fresh water after I use it

regardless I'll be taking the head off, then I can check out the cylinders etc.
Thanks again, I'll be looking into that today so I'll throw some pictures up if possible
 
http://www.marineengine.com/newparts/part_details.php?pnum=OMC0394116
Its hard to see your pic of the pump housing it looks like there are grooves in the upper surface. That can cause the pump to not work properly. This is a good price for a complete water pump. You should get a good spray of water out the exhaust relief holes on the exhaust housing as soon as you start the motor. Just hold your hand there and hot water should drip off your fingers after the engine warms up.
 
I'll have a look at it again. I'm pretty sure it's not grooved though (easy enough to check)
I found a decent deal on a head gasket (13$) which is cheaper than buying gasket material!

i'm curious if anyone know where one can get a reasonably priced longshaft kit for this model?
 
Took my head off...or rather my seahorse's head The head came off cleanly but the gasket was mostly cooked onto the block
Here they both are, as is , I have most of the gasket cleaned off the block, I used a nylon scraper I made. the water jacket on the block looks pretty good as does the head except for a weird bit of black tube like stuff which seems to be blocking the bottom end, it was crusty and came out, there's some deposit on the ends of the pistons but the cylinders look smooth. Do these pictures show an problems or potential difficulties?

seahorse head.jpgseahorse block .jpgseahorse cylinder.jpgseahorse cylinder2.jpg
 

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Toxophilite said:
For some reason I can't look at the previous posts by other forum members. I can only see my posts, Is this because the thread is a couple years old? I was hoping to revisit some of the information offered as it's been a while.
Thanks
Click to expand...

I was reading this thread and seeing the same thing. Recently, I got booted in the same way, and apparently all my messages were deleted at the same time. Talk about "terminated with extreme prejudice"!

I would like to see the responses that were guiding you.
 
Sounds like a good idea for another thread. Start one up and I will chime in as a member who didn't get accidentally terminated but was still adversely affected by it.
 
Pull the powerhead and clean all the cooling circuits good! It probably needs a new grommet where the water tube goes into the exhaust housing under the powerhead. I stuff rags into the cylindersa and with a large fine flat file carefully clean up the block where the head bolts on.
 
hmm pull the powerhead.. this is starting to sound like I should've purchase a gasket kit instead of just a head gasket.
I have the manual pdf and I'm usually good with manuals but I wish there were some better pictures.
How hard is it to pull the powerhead?
 
hmm are you referring to the thing I discovered at the bottom of the actual (removable) head (which looked vaguely tube-like) or the one one in the top of the water jacket above the pistons? The only thing the thing in the bottom of the head would've done would've been to restrict the flow of water?

I need %$#$^% pictures1 there's not much on the internet for this particular engine.
 
That little rubber thing you forgot to show us was probably a chunk of old impeller and likely there are more pieces stuffing up the works. You could have taken it apart and put it back together five times by now. Just buy a base gasket and exhaust cover gasket and clean it up good while waiting for parts.
 
It's on the left side of the picture of the head,Just gunk, not factory installed but it did look like a segment of tube on an angle, shouldn't even have mentioned it
Had to do some circus archery rigging last night at 2am, had a music show prior so I haven't been taking things apart yet.
Thanks for the help, will do!
 
Head gasket came in, I got the sierra part number off a 'Johnson dealer' The marine store that got it in says I wouldn't have been able to make it myself as it has metal rings around the cylinders.......right. Next time I'm going to get the *&$%#^%$ part number myself and give it to the people ordering it as I think this is the wrong unit. Must go check in person head and former gasket in hand.
 
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