1957 35 hp Johnson seahorse won't start

[Castellina]

I have a Johnson and I can't get it to run. It has spark, good compression, gas is getting to carb, new hoses, new coil,condenser and points. I'm stuck I don't know what to do next. It hasn't been started for about 20 years. Any help would be appreciated. Thanks.

 

[HighTrim]

Re: 1957 35 hp Johnson seahorse won't start

Glad you got the post sorted out.

So some specifics, which motor is this, is it the standard 35hp or the Javelin? Manual start or electric?

What exactly is the compression? Are you testing the spark on an adjustable tester set to 1/4" gap? Will it jump that with a bright blue ZAP!!?

Is it still set up to run on a pressure tank or does it have a fuel pump?

Have you tried putting pre mix directly into the cylinders? IF so, will it fire and run for a few seconds?

Are you trying to start it manually or with the starter if so equipped?

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

It is the standard rde-19m
I tested the spark by unplugging the lead and plugging the spark plug back in and grounding the plug. The spark isn't that great it's kind of weak.
It has a pressure tank,
I have tried putting mix into the cylinders. Not much though just a couple of drops. I'd didn't even try to fire.
I have been trying to start it manually and electric. It has both. Thanks

 

[HighTrim]

Re: 1957 35 hp Johnson seahorse won't start

You will need an adjustable gap tester to verify spark. Holding the plug isnt a sufficient test, it needs to be able to jump a 1/4" open air gap to be able to fire in the cylinder. You could also make one fairly easily, google it if you dont have a store nearby to pick one up, they are very cheap though, like 5 bucks.

I think you may need to pull that flywheel again to ensure that the points are set to 020, and CLEAN! Take a business card, dip it in acetone and run it through them after they are set. Even fingerprints can limit spark.

When you installed the coils, did you ensure the laminations were flush with the edge of the mounting boss? Too far back and you will limit spark, too far out and the coil will hit the flywheel.

Also, how are the plug leads? Were they replaced? Are you getting a reading when you put your probes on the coil ground and then inside the plug boot?

What were the compression readings?

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

I will get a tester to verify the spark.
I will make sure the points are set to .020 and clean them.
I'll check if the coil is flush with the mounting boss. The plug leads are brand new, I just replaced them a couple of days ago. I'm not sure what the compression readings are, but by pulling the recoil starter it felt very strong. I don't have a compression tester. Thanks for your help. I appreciate it.

 

[jasper60103]

Re: 1957 35 hp Johnson seahorse won't start

I will get a tester to verify the spark.
I will make sure the points are set to .020 and clean them.
I'll check if the coil is flush with the mounting boss. The plug leads are brand new, I just replaced them a couple of days ago. I'm not sure what the compression readings are, but by pulling the recoil starter it felt very strong. I don't have a compression tester. Thanks for your help. I appreciate it.

FYI. Autozone and Oreillys autp parts stores loan compression testers for free.

 

[HighTrim]

Re: 1957 35 hp Johnson seahorse won't start

Perhaps you could rent a tester, or borrow one from a friend>?

If the compression is not suitable, you are beating a dead horse as they say.

When testing spark, remove the plugs, ground the leads to the block with leads with alligator clips, then crank with the starter. Watch for the spark to jump with gap with a bright blue ZAP!!. You should be able to audibly hear it as well.

If you go over everything and still cannot get spark, disconnect the black lead at the points coming from the cutout switch and see if spark returns.

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

Ok thank. You have been a big help to me.

 

[kfa4303]

Re: 1957 35 hp Johnson seahorse won't start

These may help too. Assuming the compression is ok, all the rest is pretty easy to fix.

Reviving a Vintage Big Twin - Part 1

Vintage Evinrude Johnson Outboard Parts & Diagrams - Catalog 377023

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

They helped. Thanks

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

The compression readings were 73 psi in both top and bottom cylinders. The spark was 22,000 volts. It was just under a 1/4 of an inch. The points are clean and set to .020 but one point I a little off set. And the coils are flush with the mounting boss. Thanks.

 

[HighTrim]

Re: 1957 35 hp Johnson seahorse won't start

73 psi using the electric starter with the plugs out?

If so much too low. May get lucky with a simple head gasket and dressing the head, but will have to pull the head to find out. She wont start with that compression.

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

73 psi using manual start. and with the one plug in, and the other one out because the tester was in the spark plug hole.

 

[HighTrim]

Re: 1957 35 hp Johnson seahorse won't start

Pull both plugs out, ground the leads, and try using the electric start.

Let us know what you find.

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

Take both plugs out ground the spark plug wire leads and use electric start to test for compression?

 

[nwcove]

Re: 1957 35 hp Johnson seahorse won't start

Yup.

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

The top cylinder was 58 psi I have to wait like 10 min to do the bottom one because the starter is old and gets hot

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

The top is 58 and bottom is 29 psi

 

[1946Zephyr]

Re: 1957 35 hp Johnson seahorse won't start

58 and 29 with the starter? it sounds like your head gasket just blew. One thing that can fool us on those motors too, are the compression release mechanism on the head. if you pull start it, those reduce the compression, so our weak bodies can pull start them. That is of course if their working properly. But now if you're getting less with the starter, then something must have went south, with the head gasket.

 

[Castellina]

Re: 1957 35 hp Johnson seahorse won't start

I will replace the head gasket. Any other suggestions? Thanks