Is it possible to morph a SJP and a EFPC?

[mashenden]

I have a EFPCL232FF1 (1981) that has a great lower unit, but the top end is seized - piston is stuck.

I also have a SJP16203 (1960) that has a good top end, but the shaft is in bad shape.

I really like the idea of a Seagull with a clutch, but I am not fond of the recoil. I much prefer the older flywheel look. Can I unbolt the two nuts below the head that hold the EFPC shaft to the head and put the lower unit onto the SJP's top end?

[Horsley-Anarak]

Yes it will work.

You can stick the recoil and CDi on all Seagulls, I have not tried it on a Marston yet, but may give it a go.

Have done it to century, 40+, Featherweight, 102.

H-A

[Stelios_Rjk]

Welcome!

It is against the laws of purity but apart from that it would be a trouble free swap. Just make sure that you will fit the water transfer pipe in its hole. You will see this pipe coming out of the exhaust when attempting the swap. It's just those two nuts and fitting this pipe in the hole inside the lower end of the exhaust.

[mashenden]

Thank you both for the quick replies. I agree - it would be a bit unpure, but I would keep the parts in case I want to go back. Arguably, the old top end and newer lower unit even with a clutch would look more pure than a Seagull with a recoil on the top! .

While I am on the topic of the recoil... How does that monstrosity come off? I removed the two flat head screws that go in horizontally, and then removed the 4 hex bolts that attach upward vertically. It is loose and moves up a bit vertically, but will not lift free of the motor. Something is holding it on. Is drilling out the rivets the next step??

Reason for asking is that I would first like to get the EFPC's piston to break loose but using the recoil and putting pressure on the prop is not getting the job done, even after applying some heat.

[Horsley-Anarak]

Remove recoil, after removing two flat head screws. There can be some corrosion, but tap it off with a bit of wood.

It is this bit.

Under that bit will be the rope pull and the end of the crank with a nut on top.

Remove the nut, and then the aluminium flywheel surround will come off.

Before removing the flywheel, read back through many posts on the subject.

Let us know how you get on.

Post pictures " we all love to see a few picture".

good luck.

H-A

[mashenden]

Very helpful - many thanks!! The recoil came off after quite a bit of tapping with a piece of wood. With the recoil gone I was able to put a wrench on the flywheel nut and got the piston moving. It feels pretty good except at the near top, where the piston feels like it is hitting some resistance. The plug is out so it is not compression... Presumably it is the the rust or whatever that caused it to stick.

Any suggestions on how to smooth that out or do I have to take the head off?

[mashenden]

Here is a pic of the EFPC with the recoil top and a few other vitals off.


Here is a pic of the old SJP

[Horsley-Anarak]

I would oil up the bore first and turn it over a rew times.
If it loosens up you may be ok.
If not remove head, that will let you see condition of bore, also you will be able to clean the water passages out.
H-A

P.S.they both look good, have you got all the bits, carbs etc?

[mashenden]

I would oil up the bore first and turn it over a rew times.
If it loosens up you may be ok.
If not remove head, that will let you see condition of bore, also you will be able to clean the water passages out.
H-A

I'll give that a try. That was my gut feel but did not want to do that and then find I had made an irreversible error.

[Charles uk]

If the piston is in the top half of the bore, I would fill the cylinder right up to the top of the plug hole, with a 10 : 1 diesel / two-stroke oil mix, replace the spark plug with as little air as possible trapped inside there & gently warm the head, with a gas torch or electric paint stripper until it's almost too hot to touch & the whole cylinder gets hot.

This will force the hot diesel mix down the piston sides & possibily break the dry sieze, a few lightish taps with a 1/2" wooden dowel might help, there are a lot of pistons with holes in the crown from being heavy handed with the hammer.

A pencil mark on the flywheel & the mag base plate will show any movement, a couple of table spoons of the diesel mix in the inlet port shaken around so everything in the bottom half is well lubed wouldn't hurt.

As H-A said read posts on flywheel removal, it might be very tight looking at the rest of the motor, penetrating oil helps.

[mashenden]

Thank you, Charles. Good info but the piston broke loose after I removed the recoil and put a wrench on the flywheel nut. Now all that remains as the piston moves is resistance at the top of the piston stroke, presumably at the location of the rust or whatever from the piston sticking.

[Stelios_Rjk]

Well for me it depends on the mood and how far you would like to go. Lubrication is a solution but taking out the head and the cylinder to inspect also the piston rings, piston, bore and water ways.. is another trip. That includes gasket making/handling etc. It is until you do it the first 1-2 times. Then it becomes a routine.
The worst case scenario is that you could brake a bolt or not good sealing after closing the powerhead.

Ask for any advice and here we are.

[phil]

The head needs to come off in my opinion, if it happens to have a broken ring you certainly do not want to run it that way.
Head off will allow you to clean the water jacket out as mentioned, as well as assessing the condition of the bore. To do a proper job the crankcase needs to be opened and the piston removed. Only then can you be sure everything is up to spec so you can run it with confidence.

[mashenden]

I had come to the same conclusion about at least pulling the head. The good news is that it appears to have been done before by a previous owner, in that it (the EFPC) has SS hex bolts rather than the flat head bolts. But then again, the PO may have pulled the head, found trouble, put it back together, and then sold it to me. If so, I'll use match the lower unit with the top end from the SJP, as originally planned.

In regards to a previous question, yes I do have most, possibly all, of the parts from both motors. Some of the pieces from the SJP look a bit rough but nothing time and money can't fix I have a spare magneto, flywheel, and set of points for the SJP, and based on a previous comment, it sounds like I could alternately use the CDI electronic unit from the EFPC in the SJP. All kinds of options to make Frankengull. Hopefully one day I can exclaim "ITS ALIVE!!!"

[mashenden]

Looks good inside. There was a bit of crud pushed to the top, but overall it looks good inside the bore and inside the jacket.

However, there is still a double blip of resistance at the top of the stroke as I turn the flywheel. Do you think that I am just feeling the magnet in the flywheel?