cylinder changeout

[gcw47]

Hello all - I'm needing to replace the cylinder block on a 40+longshaft. The book calls for complete seperation of the power head from the lower unit. Is this necessary or can the cylinder be changed with the engine otherwise intact? I'll also be putting on new piston rings. Thanks in advance - first time to try to save an old seagull .

[billyboy]

not absolutely necessary but it is only 2 nuts to undo and makes it a bit easier to wriggle the piston into the cylinder

[Hugz]

I disagree, the block won't separate enough without removing the exhaust tube, but as bb says it is a simple process to drop the leg but you will need the correct spanner. Actually the tube can stay but the bottom end need to come off as you wont get enough spread.

[billyboy]

hugz is probably right there. i was working on the assumption that the exhaust tube would detach itself as soon as there was any separation between block and crankcase after which the block should be able to lift slightly to allow this to occur. have never actually done it this way so if i am wrong i apologise.

[gcw47]

Cylinder is off, new one is on the way. I took the power head off and the process was easy, except the water tube stayed in the lower unit, apparently seized in. I may be able to work it out, but thought I can just as easily reassemble it to the cylinder end after the new block is in place. There appears to be enough room with the silencer tube slid down.
My real question now is, is there a right way - or wrong way- to put on new piston rings? I have 2 new ones at the ready. There was only 1 ring in the engine- the PO broke the other one trying to get it out. The piston is good and clean and I have not removed it from the rod. I also broke the 2nd old one removing it.
Thanks GCW

[billyboy]

just make sure when you insert the piston into the cylinder that you have the rings fully compressed and that their ends are pushed against their respective pegs which are located on opposite sides of the piston.a little lubrication wont hurt either.....DONT BREAK THE NEW RINGS!

[gcw47]

What I'm really concerned with is slipping the new rings onto the piston and into their grooves without breaking them. I'm assuming use of lubricant , easing them on slowly and nudging them into position little by little.?

[billyboy]

yes.....just a matter of being careful with maybe a little oil. you can use a little moderate heat to expand them a bit if you need to. even standing them in boiling water fora few minutes should help.

[gcw47]

Good information from all and appreciated. I got the new rings on with no problem. An oil bath helped. Luckily I noticed the rings have a taper on the ends which are supposed to match up with the retaining pins, I suppose. I'm now awaiting a new cylinder block to show up, along with a new gasket and I'll try to get it back together and go from there.
After this, I have a WCL I was practically given that is in need of attention. I thought it was seized at first, flywheel wouldn't budge, but it turned out to be only full of dirt-dauber nests.