johnson sea horse 75

[steamking123]

I just got a new johnson sea horse 75. I am not sure of the year but someone said they only made that size in 61-65.

It hadnt run in a year. I went through the top secret file and read about how to bring back an engine.

This is what I have done
New spark plugs
Checked compression (all are good)
new gas hoses to all connection
set timing
took apart carbs soaked them in carb cleaner overnight and then blew them out with compressed air.
Replaced two of the seals inside the carb
Re assembled the carbs and put back together.

When I turn it over and it wont start but if I give it gas then it will momentarily start for a few seconds and then die again.
I am baffled. I don't know what else it could be?
Does anyone have any ideas?

What would happen if I wasnt getting a good seal on my float?

Thanks Derek

[bktheking]

It would flood out the top of the carb. Fuel pump working?

[lindy46]

You say you give it gas and it starts momentarily. By giving it gas, do you mean you are spraying gas directly into the carbs? If so, then carbs are still not clean or fuel pump is not working. Are the spark plugs dry after it quits? If they are wet with gas, then you have an ignition problem.

[oldrudedude]

What is the model number? What are you using for a spec reference? Do you have a manual?

[steamking123]

Model # is 2074882. I cant seem to find out what year this motor is. any ideas?

I have the manual for my other motor which is a johnson 59. The motor is basically identical. That is what I am using for my specs. are there going to be any differences in specs such as spark plug gaps, points, etc.

When I say give it gas, I mean I open up the throttle on the carb. I am not spraying gas directly in the carbs.

I took apart the carb again, and cleaned everything again, and blew out out the holes and orifices again. The only jets I couldn't get to are the jets in the drain screws on front of the carb (high speed) because they are stripped out and would not come out. Instead I sprayed cleaner, then q-tiped- then ran small wire through the hole, then blew air both ways. every orifice on the carb is clean and allows air flow easily.

After trying to start it for awhile I checked all of the spark plugs they were all dry and looked as if they were firing. each of the cylinders was equally warm to the touch (like each cylinder was firing)

I also made sure the float was closing properly and it was opening and completely closing perfectly.

Also I took off fuel inlet hose at the top of the carb and turned the machine over. plenty of gas pumped out. (fuel pump is working correctly) I took apart the fuel pump just to look a the diaphragm and inside, and it was virtually spotless and the diaphragm still looked very good.

A few other things to mention. While turning over the motor with no throttle it almost starts and nearly fires simultaneously with the starter until starter disengages and machine immediately dies. if I give it only a little gas (open of throttle the machine starts and runs from 2-8 seconds. if I open up throttle all the way it runs for 1-2 second then dies, but does a lot of backfiring if I do this much.

I am still stuck. any ideas

Derek

[steamking123]

Correction:
the above number is the serial # not the model #. I can't find the model # anywhere on the motor

serial #2074882

[vegasphotoman]

I wonder if the timing belt is missing teeth or timing is off.......
check your manual for checking that out (easy)...
check idle jet settings?
is it a water fed choke? make sure you have those hoses correct or it can ruin a motor (if they are reversed)

[steamking123]

I checked the timing marks and they were perfect aligned. I took off the magneto wheel to look at points. they were clean and appeared to be at .2 but I reset and cleaned them just to be safe. I also reset timing marks.

I inspected the timing belt for missing links and it is in good repair.
Not sure if my auto choke is water fed, but Im pretty sure hoses are in correct spots. but I think the choke runs on air pressure from cylinders.

What is my idle jet? is that my slow speed settings? (if so I reset these to 1.5 turns again. ) If not where is this jet.

I rechecked compression in all cylinders. they are from 62-70 throughout.
Each spark plug puts out a wonderful blue spark while turning over.

So if My timing is on, and each spark plug is firing, does that mean that the problem is not electrical. Some of the wires are old. but if it was electrical i wouldn't get spark at all right?

If my logic is correct, and I am getting correct spark at the right time, and I have good compression, and my carbs are clean and pumping gas, and high and slow speeds are set correct, I should be running good. Then Why am I not?

I know that this machine discharges excess gas, and I have seen this question a hundred times on these forums, but how do I know if my machine is spitting out too much nasty fuel from the bottom. Whats too much?

Derek

[bktheking]

Am I missing something here, does a 60's 75hp evinrude even have a timing belt???? Timing belts are for 4 stroke motors with camshafts and valves, old 2 strokes are sans timing belts. The only belts under the hoods back then were for generators and had nothing to do with timing. Maybe i'm wrong, if I am please explain.

[bktheking]

I

I know that this machine discharges excess gas, and I have seen this question a hundred times on these forums, but how do I know if my machine is spitting out too much nasty fuel from the bottom. Whats too much?

Derek

When is it doing this, cranking or pumping the bulb? If it does it pumping the bulb then the needle is not seating in the carb. If it is doing this while cranking it could be bad reed valves.

[coolguy147]

this motor has a magneto

i would put the low speed needle at 1 1/2 turns out and high speed needle 1 turn out to start with.

do you think its sneezing or miss firing? both sound alike in a way. replace your impeller.

check compression before anything too.

24:1 mixture tcw-3 2 stroke outboard oil

[steamking123]

I missed labeled the timing belt. What I meant was the belt that runs from the motor shaft to the magneto. I guess its not called a timing belt.

Fuel only spits out the bottom when cranking. I double checked the float to make sure it was closing when carb was full of gas. after priming a few times I can feel the float close and no more gas will flow.

I set the low speed at 1.5 and the high speed setting at one and no change. In fact I tried everywhere from 0 turns to completely out and there is no change in anything the way the motor sounds.

What is sneezing and what is miss firing.

and what is an impeller.

excuse my ignorance.

Not sure what kind of oil I am using but its 24-1 ratio and the local auto parts store gave it to me. it said marine 2 stroke motor oil. Im guess that is right?

I checked to compression today. 62-70 psi in all cylinders
I spent an hour searching the archives of these forums today and reading how to get the most from my questions (something i should have done from the start)
on the archives over and over again, new guys would come on with my problem or a similar problem, and after removing the carb 3 times and cleaning 3 times most of the problems were solved. I am gonna go back to the basics. Cleaning carb again. I have good spark, good compression, its almost for sure carburation. This time I am going to soak overnight instead of using the spray can. I am also going to replace all the rings. I feel kinda sheepish for trying take the cheap way out. These Archives are proof that new guys always want to go the cheap route but it never pays off. lol its hard to pay 75 bucks for a carb clean and rebuild when I only paid 75 for the motor.

I will let you know how it goes

[vegasphotoman]

the impeller pumps the water thru the engine, it is made of rubber and is inside of the lower 1/2 of the outboard.....
it is SUPER important! you will fry your engine and overheat it if it is no good (and if your motor hasnt been used in 3 to 100 years it is most likely bad and must be replaced before using the motor

you can prob get away with water ears for testing it out but I wouldnt run it for extended periods until you replace the impeller!

go here they are cheap....
Iboats shop to see what they look like / cost etc..

youll also need lube and a few gaskets...and a manual to tear it down and re assemble
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[F_R]

steamking, you insist the timing is correct. Would you please humor me and explain just how it is timed? Then I'll believe you got it right.

How about the magneto/carburetor linkage synchronization? Are you confident that you have that right?

ALSO, even if you have the belt timed correctly, it wouldn't mean beans if the flywheel key is sheared.

I think your compression is a bit on the low side, but don't honestly know what should be expected.

I have no arguement concerning the impeller, but if it were me, I'd at least want to know this beast is going to start and run before digging into something else. Even without a water pump, you aren't going to hurt it by starting it up and running it for a few seconds. Note, I did not say run it till it gets hot. One thing at a time.

[steamking123]

ok here is how I aligned the timing.

The mark on the magneto casing, the mark on the condenser house and the mark on the flywheel above the magneto flywheel where all aligned with the belt off. then I aligned the linkage cable(the mark on the brass thing) directly with the little roller on the carb. Then I turned the main flywheel until the mark on it was directly above the mark on the motor block. Then I put the belt back on so that all these marks where still aligned. Did I miss anything?
I don't know if I was very clear. 3 marks by magneto aligned. 2 marks on motor and flywheel, and 1 mark on linkage cable.

If it was something stupid with timing I am going to be so happy.
I read instructions from manual very carefully and have timed my previous motor after I replaced magneto.

Please let me know what you think

[steamking123]

I am soaking my carbs right now in a nice steamy bath of carb cleaner. But I am pretty sure I jacked up my slow speed jets. They are two little jets inside the drain screws on the front of the carb. I used a little flat head screw driver combined with an attachment to an impact wrench (the the metal screw driver that you hit and it turns just a little bit) don't know if thats what its called.
I got on jet half way before I pretty much demolited it. Now its stuck. how do I get it out and how do I get out the other one without doing the same thing.

Also to order replacements I am going to need to know the year of my motor. How do I do this?
stamp on block with johnson logo says 2074882

[Willyclay]

F R is on the thread and he is one of the forum experts who can help you. While I am not an expert, I have scanned and saved a non-factory service manual that covers all 50-85HP OMC V4 outboard motors built from 1958-68. If you would like a free copy, send me a Private Message with your email address and I will reply with it attached. Good luck!

[F_R]

ok here is how I aligned the timing.

The mark on the magneto casing, the mark on the condenser house and the mark on the flywheel above the magneto flywheel where all aligned with the belt off. then I aligned the linkage cable(the mark on the brass thing) directly with the little roller on the carb. Then I turned the main flywheel until the mark on it was directly above the mark on the motor block. Then I put the belt back on so that all these marks where still aligned. Did I miss anything?
I don't know if I was very clear. 3 marks by magneto aligned. 2 marks on motor and flywheel, and 1 mark on linkage cable.

If it was something stupid with timing I am going to be so happy.
I read instructions from manual very carefully and have timed my previous motor after I replaced magneto.

Please let me know what you think

The belt timing and the carburetor relationship (synchronization) are two separate steps. If you PM me your e-mail address, maybe I can help with some pictures.

Sounds like you have really done a number on the carburetor, right? Those orifice plugs are the high speed jets, not idle. They are a precision part. Or at least they were. You are supposed to use a special screwdriver to get them out. Otherwise, the more you mess with them, the worse it gets---as you found out. At this point, they will probably have to be drilled out. That is going to take great care to prevent damage to the carburetor body.

[steamking123]

Yes I messed up those high speed jets pretty bad. lucky I have a spare from my 59 evinrude and its indentical. I soaked the whole carb last night (bottom half of other one included) blew all orfices again and its clean im sure.

I reinstalled the carb and i am having the exact same problem. basically no change. Although the first few times that I turned it over it ran better and longer then it usually does. then after trying a few times it is exactly where I started. Motor wants to start and fires along with starter but dies immediately. and will start for a sec or two if I open up throttle.

Now I am really lost. maybe it is something to do with timing. what do you think

Derek

[steamking123]

So I carefully read the instructions on how to time magneto and sync throttle to magneto. The throttle linkage was a little off but the belt timing was correct.
When I was starting it earlier I was opening the throttle by actually opening the throttle arm that comes directly out of the carb, so that linkage made no difference although it saved me a step later down the road once I get it running.

So now im completely out of Ideas. As far as I know I have decent compression, good spark, properly timed magneto, carbs are clean.

Any ideas?

Derek

[F_R]

So I carefully read the instructions on how to time magneto and sync throttle to magneto. The throttle linkage was a little off but the belt timing was correct.
When I was starting it earlier I was opening the throttle by actually opening the throttle arm that comes directly out of the carb, so that linkage made no difference although it saved me a step later down the road once I get it running.

So now im completely out of Ideas. As far as I know I have decent compression, good spark, properly timed magneto, carbs are clean.

Any ideas?

Derek

Well, if everything is as you say it is, I'm about out of ideas too. But just a comment, I hope you aren't still opening the throttle at the carburetor. That will stop even a good running motor. The spark has to be advanced at the same time or it will immediatly conk out. That's why the sync adjustments are so important.

Still unanswered is the flywheel key question---or I missed the answer. Are we positive that the spark plug wires are on the right plugs and/or in the right towers on the cap? Do we know that something hasn't fallen down through the carburetor and is blocking a reed open?

[steamking123]

I guess that makes sense about using the throttle arm. I won't do that anymore.

I double checked that the spark plug wires and the corresponding spark plugs. I looked at the numbers that are on the magneto casing and then followed them to each cylinder. Correct me if Im wrong. If I am looking at the motor from behind the boat it goes like this.
top right cylinder is #1
top left is #2
bottom right #3
bottom left is #4

As far as the reed goes, I don't really know. I have never taken apart anything below the carb. Is that something I need to do? What is a reed and how would I know if it was functioning?

Also in regards to the flywheel key. Are you referring to the flywheel above the magneto? When I looked at the condenser points the metal piece you slide the flywheel onto (to hold the flywheel consistent on the shaft) it was in good repair. The flywheel and the shaft spin together.

[F_R]

I guess that makes sense about using the throttle arm. I won't do that anymore.

I double checked that the spark plug wires and the corresponding spark plugs. I looked at the numbers that are on the magneto casing and then followed them to each cylinder. Correct me if Im wrong. If I am looking at the motor from behind the boat it goes like this.
top right cylinder is #1
top left is #2
bottom right #3
bottom left is #4

As far as the reed goes, I don't really know. I have never taken apart anything below the carb. Is that something I need to do? What is a reed and how would I know if it was functioning?

Also in regards to the flywheel key. Are you referring to the flywheel above the magneto? When I looked at the condenser points the metal piece you slide the flywheel onto (to hold the flywheel consistent on the shaft) it was in good repair. The flywheel and the shaft spin together.

The carburetor is mounted on the intake manifold. Between the intake manifold and powerhead is a plate about 1/4" thick---the reed plate. Mounted on the reed plate are a whole bunch of reeds---OMC calls them leaf valves. They are thin pieces of spring steel that act as flapper valves allowing fuel & air to pass only in one direction. Failure of one is extrmely rare.

The "Flywheel" is that honkin' big rotating piece under the recoil starter. It is keyed to the crankshaft. If the key is sheared, the flywheel (and belt and magneto) are out of time in relation to the crankshaft. The key never fails if the parts are good and they are assembled correctly. However, if somebody had it apart and DIDN"T assemble it correctly, key shearing is almost guaranteed. Also almost guaranteed is catastrophic damage to the flywheel and crankshaft. Your manual should show the correct procedure--read and heed.

[steamking123]

Its running. finally it starts and runs. it definitely runs rough but it stays running most of the time.
I am not exactly sure what made it run. When I did the link between carb and mag, I tried to start it but it didn't run. I increased my idle today and it pretty much fired right up. I guess it must of been a combo between linkage and idle settings.
I didn't let it run very long because I was afraid of overheating. Someone mentioned that I have to replace my impeller before I let it run much. is there a way to test to see if impeller is working correctly.

[cougar1985]

Its running. finally it starts and runs. it definitely runs rough but it stays running most of the time.
I am not exactly sure what made it run. When I did the link between carb and mag, I tried to start it but it didn't run. I increased my idle today and it pretty much fired right up. I guess it must of been a combo between linkage and idle settings.
I didn't let it run very long because I was afraid of overheating. Someone mentioned that I have to replace my impeller before I let it run much. is there a way to test to see if impeller is working correctly.

i have the 63 evinrude version of yours ,75 starflite.i used a cheap large tote box and filled her full of water and lowered the motor into it,started and after a few seconds you should be able to put your hand by the hole in the mid-leg of your motor and you will feel water spitting out.its the same hole the exhaust comes out of.also feel the cylinders with your hand ,if their hot to the touch your impeller is not working.the safest way is, if your not sure, to replace the impeller and then you will be sure!