Outboard Cylinder / .010" Rebore Using Hone ?

[s/vAngel]

Have never needed to use my 3-stone cylinder hone tool, so have no idea if this would work:
Would that simple, drill-powered tool be able to take off enough material to rebore my 15hp outboard's cylinders to .010 oversize?

Have some scoring & a bad piston, and have no choice but to rebuild, and rebore. There's a parts dealer that has .010 over pistons/rings available.
Wondering if anyone has tried this with a hone. Such a total rebuild of powerhead to new to me. have rebuilt lower units/gear boxes, but now I'm now in new, and intimidating, territory. Can take it to a shop, but have to wait and cruise closer to where one is!
That ouboard is my main transportation and how I get to work daily when not cruising...it overheated and BLAM, serious damage in seconds...what a drag!!

Don't make my stupid mistake, always check if water's coming out of your outboard's pisser.

[Cheechako]

are parts less than another used engine? have you mic'd the existing bore? could be worn 10 over aready...? How big and brand of engine?. Just thinking out loud.... That method was obviously used for an engine over haul in years gone by to deglaze the cylinders. Seems everything gets a total rebuild now days....

[David M]

It should be bored out to insure the bore remains the same throughout the entire stroke....just in case it is not. As Cheech said, hones are good for removing the glaze. If you are going to break an engine this far down then why not make certain it is right?

[knotnow]

Nope – Nada – Wouldn’t work.

I’ve been rebuilding outboards for over 40 years as a livelihood. Do most of the machine work for local dealers. You’re question using a hone and just oversized rings won’t work. The typical piston to cylinder clearance of .0005 to .003 and has to remain constant in the bore. At the large clearance ends that’s still smaller then a human hair. Especially a red head, usually .005. Usual boring in the states is 60.00 a hole and piston, rings and gasket set can easily add a few hundred more. Ya better love that OB

[s/vAngel]

The above advice is perfect & I really learned some useful things here. After double checking allowable cyl taper & mating surfaces of head- to be sure the bugger's still useable, will take the block into a shop and have it done right.
Found out that there are aftermarket oversize pistons available for this outboard and a handy rebuild kit with all new seals, bearings, etc. If things go right, it'll be like having a new engine.
thanks again!!
Rebecca

[Cheechako]

sTILL DONT KNOW WHAT BRAND OF ob IT IS, BUT ONE OF THE FEW THINGS THAT HAVE GONE WRONG WITH MINE WAS THE MAIN BEARINGS. iT JUST STARTED VIBRATING BAD WHEN REVVED UP AND WOULDNT REACH PROPER RPM. AN EX OB REBUILDER KNEW WHAT IT WAS IMMEDIATELY. HE HELPED ME PUT THEM IN IN ABOUT 2 HOURS. JUST SAYIN, DONT NEGLECT THAT POSSIBILITY. Whoops... I'm shouting!

[s/vAngel]

Oops! the ob is a Johnson 2-stroke, year 2000- but lightly used. Am guessing that when it overheated, that's when those deepish scores happened in the cyl. and the head warped a bit. (still okay with their recommended .003 tolerance & can be faced)
Totally disassembled the powerhead & cleaned the parts. Bearings were okay, but, huh, the upper and lower crankcase seals were bad and leaking. Ah-hah!- all that oil coming from under the flywheel was due to a leaking top seal...interesting...and all that time I thought that oily condition was "normal".
measured cyl's w/ bore gauge & good news, the block is reusable so can be taken to machine shop for larger bore to fit those larger, .010 or, depending on depth of score marks, .020" oversize aftermarket pistons.
The hard part will be putting all the parts back together and not having some screw, bolt or o-ring left over, that'd be my dumb luck

[knotnow]

You will prob. be boring to .020 as @ .010 that would mean only removing .005 per side. If you can feel that grove it's over that. I always bore to piston skirt clearance as sometime the pistons are not dead nuts on.

Good luck