Saving Old Seagulls

Hi, last night I bought a 25hp Blue band Merc and had a Seagull thrown in to the deal for free. I'm more excited about the Seagull than the Mercury!
The number on it SJP1415E6 indicates that it's a May 1966 Forty Plus model.
It's seized, whether that is through standing or failure I'm not sure.
The only thing I'm going to do to begin with is remove the plug and get some WD down into the chamber, I'll do this for a few days then start having a closer look. I may follow the WD with some diesel or heated oil to try and release it.
Any comments, or help is gratefully received.
Cheers
Ricko

Welcome to the forum

40plus is a good one to start on, loads made, loads of spares available.

Post a picture so we can see what you have.

Hope for a light seize, bit of WD40 and thermal shock has worked for me.

I would strip it down at this point to check the general internal condition, remove the crankcase bolts, split the crankcase so that you can see piston in bore.

H-A

Here are some photos..

Looks Ok

If it is not free on a few days,I would take the head off and have a look at the bore, don't damage the copper gasket as you can anneal and re-use.

More WD40 and a hot air gun on the piston, few taps with a wooden drift.

It's certainly complete, although there seems to be a few bodged repairs/modifications of the clamp etc.
Yes, lots of WD will going down the plug 'ole.
Will a hot air gun be OK to warm it up??
I removed the old Champion 8 COM plug.
What should I replace it with??

Ricko wrote:I removed the old Champion 8 COM plug.
What should I replace it with??

http://www.saving-old-seagulls.co.uk/fa ... _plugs.htm

Old plug could be OK.

I've just had a look at the old plug, it's hot a funny ground electrode that doesn't sit over the centre electrode but it sits to one side!

Just squirted even more WD down there before bed, I think this will be a nightly ritual this week!

Does the flywheel move at all in either direction?
"No"

Fill your old spark plug with as much grease as you can, then with the cylinder head facing up, fill the cylinder with a diesel & two-stroke oil mix right to the top of the threads & screw the spark plug home tight after marking the base plate & flywheel to show if anything has moved.
This should get some lubricant down the side of the piston, if still no movement, warm the head with a hot air gun to heat the diesel to make it expand & push the piston.

"Yes"
The lower unit could be seized.

The piston has moved!
But it is very stiff to turn over the engine with a spanner.
Took the head off, the bore seems fine.
I'm wondering if the stiffness is the main bearing or something like that??

Charles uk wrote:The lower unit could be seized.

As Charles says gearbox could be seized, drop the leg off, only 2 nuts and a small screw if you take the exhaust off as well.

Thanks for all the support and advice.

Took the drive leg off and the head unit is still stiff to turn over.
What do you suggest next?
Magneto/flywheel off and open her up?
Does the crank case split easily?

Cheers

Yes sounds like it needs a full stripdown, flywheel removal can be the hardest, search the site for flywheel removal so you can see what is involved.

H-A

search.php?keywords=Flywheel+removal&te ... mit=Search

Right, despite being distracted by all the other 'projects', I've now removed the flywheel.
The HT lead was already cracked open at the magneto end so I'll need to replace that on the rebuild.
It's still quite stiff to turn.
What's my next step??
Many thanks

Remove cylinder, and then split the crankcase, woodruff key in top of crank will need removing (don't loose it).
Then you will be able to inspect the crank, crankcase, piston, conrod and the cylinder.

If when you are removing the crankcase bolts the crank loosens up, then good chance crank is bent or crankcase is deformed.

Keep going.

H-A

Would be interesting to know if, when the flywheel was on, when turned 360 it was out of true.