73 seahorse 4hp how to remove from case

[danray35e]

Well after determining that I had a blown head gasket and a search all over town I finally had to order one. It wont be here til Monday. So I decided to clean the mating surfaces and (don't know how I missed it ) noticed that one of the bolts apparently sheared off when I was removing the head. So I got out the pb blaster and soaked it overnight and today took some vise grips to it.
It. It sheared off again now flush with the crankcase. So I now get to drill it and try an easy out.

My question is how do i proceed to remove it from the engine housing? The aforementioned bolt is one of the lower bolts and I can't get at it with a drill because of the case. I am looking at Monday for the manual I ordered and I am completely new to outboards. Ive rebuilt my share of engines but never for a boat. I don't want to try to remove it the wrong way.

 

[ONERCBOATER]

Re: 73 seahorse 4hp how to remove from case

you can find the parts diagrams here
http://www.boats.net/parts/search/BRP/JOHNSON/1973/4W73C 1973/MOTOR COVER/parts.html

not sure as i am just looking at the diagrams..... but it appears that you will not have too bad a time removing the engine.

That said, if you put your model number,yr, etc... up we can be sure that we are both looking at the same model.... you will also get more help that way

another thing worth noting most of the parts you may need for that engine are available on this site, worth looking at. Oh, and if your going in this far I would say clean everything up on the engine and repaint it while you are there, but that is just me.

Sean

 

[danray35e]

Re: 73 seahorse 4hp how to remove from case

I have see the parts diagram but that doesn't tell me what to remove, and the proper sequence to remove them in. I mean I don't know if I should start from the bottom or start from the top. Remove the flywheel or not. Or will it be as simple as removing the bolts on the bottom of case and just lift off.
There were only two model numbers for this year.
mine is 4w73 c weedless prop

 

[F_R]

Re: 73 seahorse 4hp how to remove from case

The basics are:
1. Remove the lower unit (4 bolts)
2. Disconnect/remove any small parts between the powerhead and lower cover. (Carb knobs, throttle link, gas line, etc)
3. Remove the 4 bolts holding the lower cover to the swivel/exhaust housing, and lift the whole lower cover and powerhead up and away.
4. Not sure, but I think the inner exhaust tube has to come off. Yeah, I think so.
5. Now remove the screws holding the lower cover to the powerhead and the powerhead will come out of the lower cover.

You will need all new gaskets to reassemble.

No guarantee that I've dotted all the i's and crossed all the t's but this should get you going.

BTW, there is no such thing as an Easy Out. It ain't easy and it won't get it out. If the screw itself wasn't strong enough to back it out, why would a fragile easy out be? Once you break it off in that screw, the game is over and you lose.

 

[danray35e]

Re: 73 seahorse 4hp how to remove from case

Thanks for the info
Yeah Ive never had any luck with easy outs either. Most likely I will just skip the easy out and drill the thing out and retap

 

[1946Zephyr]

Re: 73 seahorse 4hp how to remove from case

Easy Outs are worthless to siezed bolts. If you snap one off, you have a bigger problem. They only work on bolts that were snapped off by another problem. A case where a bolt is siezed and broke off, unfortunately, you'll have to drill it out and be very careful that you center your hole as much as you can, so you don't hog out any of the threads.

I've done too many of them.

What I found is the best thing to do, is put the head back on with the rest of the bolts finger tight and use the typ of center punch, that looks like a large dowel pin. Get one that fits the hole in the cylinder head as snug as possible and that will enable you to center punch the broken bolt, almost perfectly. The next thing is drilling the hole, as much to perpendicular as possible without wandering off at any angle. There have been times I got lucky enough to drill bolts out to where there were only threads left to dig out.

 

[ONERCBOATER]

Re: 73 seahorse 4hp how to remove from case

just a thought here.... that is a rather small engine.....and once free of the cowls and lower unit will be a very tidy package..... if it was me doing this, I would make up a strong wooden jig to hold the engine solidly in place and bolt/clamp the engine and jig to my drill press table, then drill out from there, oh and by preferance very low speed and short to very short carbide drills, or at least cobalt.
if done this way there is much much less chance of a wander than by using a hand held drill, dont forget cutting fluid (even wd40 works in a pinch) and lots of patience.

I really hope you get it out easy...and I second the thoughts on the easy outs...seized bolts and easy out are not good combination.

Sean

 

[danray35e]

Re: 73 seahorse 4hp how to remove from case

I had the same thought of using a drill press. If I had one.