Need Top Pin Piston Explained

[Dave S]

if ya make the exhaust port friendly to the rings.........balanced ring return..... the pin will be happy......

[Markus]

What decade did that happen in ... ???

No need in throwing the piston mfg. under the bus .. just what year ( approx. ) time frame ...

Around the turn of the century. Wiseco on a Yamaha. The pistol was cut, though.

[A164]

Need of pistons.
I share your concerns as I did a semi overhaul of my 260 HP outboard over 5 years ago. allot of parts was changed but I did not change the pistons, well knowing that I had some issues with loose piston ring aligning pins.
What I did was driving the pins back to the original point, and used an untraditional way to kinda lock the pin there. I forced some of the aluminium by using a punch and a hammer to lock it in place.
This I did because I was not ready to spend the money for new pistons at that time. And my use of the engine has been in the rpm range up to 7500rpm. mostly running lower. So 5 years after my overhaul in 1914 I now took my engine apart, finding my pins still in place. however looking to have been some movements. So I am thinking it must be time for some new pistons, so that I can sleep better, so I am now in the market for a good solution to my engine. Anny one know where to find replacement pistons?

[Chaz]

Pro Marine ..

http://parts.promarineusa.com/scategory/M50/1/1/30/205

[Dave S]

I like the fact that ya worked the piston....That's what you do when parts aren't easy to get..........If the pins were falling out.......ya could pull en like a dentist.... then do your own top pin........But new is easyer.

[Markus]

Need of pistons.
I share your concerns as I did a semi overhaul of my 260 HP outboard over 5 years ago. allot of parts was changed but I did not change the pistons, well knowing that I had some issues with loose piston ring aligning pins.
What I did was driving the pins back to the original point, and used an untraditional way to kinda lock the pin there. I forced some of the aluminium by using a punch and a hammer to lock it in place.
This I did because I was not ready to spend the money for new pistons at that time. And my use of the engine has been in the rpm range up to 7500rpm. mostly running lower. So 5 years after my overhaul in 1914 I now took my engine apart, finding my pins still in place. however looking to have been some movements. So I am thinking it must be time for some new pistons, so that I can sleep better, so I am now in the market for a good solution to my engine. Anny one know where to find replacement pistons?

I have a set of good used, top-pinned genuine Mercury forged Mahle pistons, top-pinned and balanced to within 1g by John Marles.

They are in Sweden, so easy to ship.

__PRESENT

[A164]

Chaz,
Good suggestion. But are this a good longtherm solution.

Dave S,
Most thing are easy to get if you want to spend the money. In my case I wanted to deside whether this engine was something for me, before spending the money for new pistons. For my use where im running in the pattern 5% idle, 15% at 2000-3500rpm, 55% at 3500-6500rpm, 25% at 6500-7500rpm. (just a rough estimation acording to my gut feeling). I found very little / almost no wear on all the new parts that I put in 5 years ago. I may have had an average of engine running of max 15hr pr year. You might say that this engine is not for my kind of use, but I like the fact that the high performance is there when somone challang me. Kind of sleeper consept on my Maxum 2000 XP boat.

Markus
When you say good used pistons, it sounds for me that they have been used fore a quite long time. (godt brugt på (Danish) betyder jo noget der godt slidt). Sorry for the language change, as I expect Markus beeing Swedish reated I assume that he can understand some Danish. :-)
Maybe you can send me some pictures?

[A164]

Just forgot to meantion, All parts that I used 5 years ago was purchsed from Jay.
http://www.jaysmithracing.com/index....tpage&Itemid=1

[A164]

Replaced parts 5 years ago:
Redone crank fron JSRE.
Lightend connecting rod.
High performance encapsulated light weight wrist pin.
Bearings.
Reeds.
Miss gaskets. etc.

[Chaz]

Chaz,
Good suggestion. But are this a good longtherm solution.

Ohh long term ... naww, I put a bunch of used **** in there with collapsed skirts, lifted ring lands, and pins that are ready to fall out ...

I just got off the phone with "The Sweedish Bikini Team" (you know they are American .. right)
They said, if they are gonna ride with you, they expect a brand new set of coated pistons from a hi-volume, stocking warehouse that will give you a good price, that ships word wide every day ...

[Dave S]

chazz ya kinin me........Omodhohho

[Dave S]

ya be besttuin the not....ladddies......

[Markus]

Markus
When you say good used pistons, it sounds for me that they have been used fore a quite long time. (godt brugt på (Danish) betyder jo noget der godt slidt). Sorry for the language change, as I expect Markus beeing Swedish reated I assume that he can understand some Danish. :-)
Maybe you can send me some pictures?

What I mean is that they are in good shape.

I can send some pictures later this week.__PRESENT

[Dave S]

The pistons Santa has are ggood...... I like Mahles.....Chazzzz is that ABBA cloned....?????

[A164]

What I mean is that they are in good shape.

I can send some pictures later this week.__PRESENT

Markus send me som pictures. If they are better than mine, and the price is right, I might be interrested.