Saving Old Seagulls

Background on motor:

1964 SJP 40 plus Long shaft

- the coil was bad so I put used OMC Sierra coil and got good spark
- point was cleaned and set at 0.020
- spark plug gapped at 0.020
- good compression and the motor runs

Problem :

Had to run the motor at higher speeds to get water flow and the flow was a bit diminished.

- removed the cylinder head and the water jackets were all junked up an was surprised water flow through water jackets.
- cleaned out all the water jackets.
- cylinder head nuts torque to 18ft pounds as suggested by SOS member.

Tried running the motor with and without the propeller.

Did notice more water flow after the water jackets were cleaned and definitely more flow with the prop off. I know running the motor on the boat in open water moving forward will help force up the water tube to the head and help improve flow more.

After running 5min.

Temp of the cylinder head around the spark plug is 220-228F

Temp of the power head on the sides is about 145F

Temp of the crank case is 130-135F

Temp of flywheel is 125F

Outside temp 95F

Question/concerns


Are these temps normal?

Does the head temps and power head temps transfer and heat up the flywheel?

Sorry for all the question but I don't want ruin this old dear.

I will post pictures a little later.

Thanks,

David

It could be the coil is making the motor running a bit hotter than normal because the ignition timing is running better than before. Ive noticed my Seagulls are running hotter than normal since ive removed the ignition points and replaced them with an ignition module. Its freed the timing up a bit. Sometimes i cant keep my fingers on the crankcase because its hot, but the water running from the tell tale is ok. So i would not think its a problem. This is what i think is wrong with yours, but dont quote me on that. Its just my opinion. See what other poeple say. My Mercury powered ski-boat used to have water coming out the tale tales so hot it was steaming and that was how they are supposed to run.

In my opinion, if you have good water flow from the telltale you should be ok. Given the temps you deal with the cylinder temp does not sound too hot to me. The head temp. will be quite hot as the only water cooling is the contact area you saw when you cleaned out the head, 220 F sounds reasonable as it is a little above the boiling temp. of water.

A lot of us in the north don't run outboards in the kind of temps you are used to. Seagull owners from places more tropical are likely to be better able to answer your questions about how hot various parts of their motors run.

In my experience, the max. water temp. going into the motor would be about 67-68 F, and that would be close to the very highest water temp. in this area. Many places around here only get to 60-62F water in the hottest part of summer! I have had it produce water warm to the touch, so maybe max.110 F max. in the outlet water. This was a Silver Century pushing a 21' sailboat of 1 ton displacement at full throttle for 45min. against 2-3 knots of current.

Here are the pictures of the motor with the cylinder head off.

Before




Prepping so debris does not get in the cylinder.




After the manual cleaning.




I heavily sprayed WD40 in the jackets and all kinds of garbage continued to come out. I then connected a hose attachment to the water tube with the lower unit off and allowed water to generously pour out for a minute or two. Cleaned everything up and put the cylinder head, gasket and torqued the head as instructed.

There was enough sand, dirt and grit in the jackets to make my own beach!!!

This is the motor running and the water flow after the water jacket cleaning.

Click on the pic for the movie to start





Sincerely appreciate your time and advice!!!

David

Id agree that if you have a good water flow you should be Ok


What you see is not just a telltale like other outboards. It is the full cooling water flow outlet. It should be running at just about full bore, not under any pressure but the stream should be equivalent to the size of the outlet. When idling the flow will be less and might stop altogether esp with a long shaft engine.

Turbulence with the prop on especially in a tank tends to cause a reduction in flow.

You can see the flow from a Featherweight ( which is a shorter shaft than a standard 40+ ) at a fast idle with the prop on but in a good sized tank



Sorry no movie or fancy temperature gauges!

BTW you should be running a 10:1 fuel oil mix using a TCW3 outboard engine oil

Yes Sir, 10:1 is in that tank and I will never lean it out. My understanding it needs to 10:1 for lubrication, keeping it cooler and also to help seal the crankcase.

1650bullet, phil , Vic, thanks guys you are starting to make me feel easier about running the old dear!!

David

You have nothing to worry about there. That's a perfect running Seagull. Your motor wont pump water if its running low in the revs or idling invade you don't know. That's how they work. Go out for a run in your boat now and enjoy.