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earlbuddy

Regular Contributor
I'm looking for 4 new standard pistons and ring sets for 1966 Evinrude 80hp Starflite.
Part numbers for pistons: 380569 or 385282
Part numbers for rings: 380110 or 382825
These are the part numbers given under the parts section for this engine on marienengine.com. Maybe some of you know other part numbers that would cross reference.
I know some are available from Marineengine.com but remember several on this forum saying they had parts available for sale too.
Thanks
 
What is the reason you are changing the pistons? I would consider boring .020 over so your sure the cylinders are nice and round and the piston to cyl clearance is within spec.
 
Not really anything noticeable maybe a few ponies. Are the cylinders nice and clean and have a good crosshatch. Being NOS the cylinders may need a light hone to clean any defects before you install new pistons. The machine shop would be able to tell you if you need standard or oversize pistons and rings?
 
Had it checked out by a machinist. All 4 in specs for standard piston. It needs crosshatched. Any suggestions on what type of hone to use and grit. I've seen this flexible hone. Any suggestions are appreciated.
Flex Hone.jpg
 
Do not use that type of deglazer it will deform the cylinders at the intake and exhaust ports.
http://cgi.ebay.com/ebaymotors/Engi...hash=item51ef585eb5:m:mtfRvpzdD51yy8gukLgAW3A
Just use one like this with the longer stones and a slow speed drill. Use lots of oil and spend the same amount of time on each cylinder and dont stop the drill until after you pull the stones out. Try and achieve a 45 degree crosshatch. Be sure and check all the rings in the cylinders for end gap just push the ring in a inch or so with the piston so its nice and square in the cylinder. I count the strokes up and down and use a 400 grit set of stones.
 
Got to disagree here.....Never use a spring type hone in a outboard as it can hang in bottom of cylinder due to step and the ports,chipping stones and scoring cylinder and mostly used in 4 stoke applications. Use a ball hone has you found in a 240 grit and it will not damage ports..the ball will break before cast iron liner will just make sure you use a good honing fluid(I use diesel fuel) and wash,wash,wash to remove honing debris. No engine (outboard) rebuilder uses a spring hone, all they use is a rigid hone and ball hones. Here some good reading to back it up...
http://www.flexhoneblog.com/2010/04...0/04/honing-tools-for-two-stroke-engines.html
 
They told us in OMC Service School years ago to use only the ball hone as it helps take the sharp edges off of the ports. I've always done this and never had any problems.
 
I have been rebuilding engines since 1978 and always used a Sunnen rigid hone and ball hone.Spring type hones are for brake cylinders, diesels and automotive deglazing.
 
That Flex Hone or"ball hone" as you call it, was introduced years ago.. The CAT hydraulic division employees quickly nicknamed them "dingle berry brushes". :)
 
I appreciate all your information. The NOS power head cylinder walls has a small amount of surface rust, no pitting. I'd like to clean them up and obtain a good crosshatch pattern. The standard bore is 3 3/8". What size, grit, and abrasive flex hone would you suggest?
 
Post # 4 clearly states a new powerhead.-------I wondered if you were going to take it apart first , that is all for now.
 
Nice just take your time you got alot of work ahead. keep all the metal parts lightly oiled it dont take long for dry parts to develop rust.
 
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