What caused this?

[jeepster21]

does any body know what caused my pistons to do this? 1989 evinrude tracker 110.

[Maple Leaf]

does any body know what caused my pistons to do this? 1989 evinrude tracker 110.

Pics are kind of small, post some bigger pics will ya;)

[faztbullet]

Looks like heavy carbon/ash buildup in ring lands...JMO

[flabum1017]

Looks like heavy carbon/ash buildup in ring lands...JMO

Either that or the locater pin fell out or got pushed in from running hot allowing the piston ring to spin around and catch in a port.

[jeepster21]

The locator pins are still there. The amazing thing is that I ran it all summer like this it was just kinda hard to start and it could still break 60 mph or so. I also made the pictures bigger hope it helps its as big as i can get them.

[flabum1017]

The crown is a good color, so you weren't running lean. The skirt looks clean.... plenty of oil. It's not a high ring piston so landing failure is slim.

It does look like there is a lot of carbon in the ring groove.

Carbon behind the rings will push the rings out and into the ports.

[jeepster21]

ill try to get a picture of the ring groove tommrow, it is all eggd out, could carbon cause that?. OH and i forgot to mention that are two pistons on the same side did same thing this is just one of them I seem to have lost the other one but that one looked like this one does. they were both on the starbord side.

[Laker]

Gotta love Xflows. 50% leak down and the symptoms are... Alittle Hard to start but still pulls good.... LOL
How many hours were on that motor? was it original?

[jeepster21]

I dont know how many hrs were on the motor but the other 2 cyls still had some cross hatching left. There was still paint on all the bolts when I took it apart so I am assuming that it was original. I was going to just keep running it, but I had to take the head off to get my socket out that i dropped in there, and what you see is what I found

[EMDSAPMGR]

A classic crossflow failure. Rings carbon up, preventing oil from getting to the ring. Top ring overheats and eventually cracks, then breaks into small pieces, rattles around the combustion chamber, denting the piston and head, then exits the exhaust. The lack of oil to the top of the piston will eventually cause it to overheat so much at high speed, that it will actually lock up in the block, then free up when it cools down and run again. My V6 locked up twice with same problem before it died. Hard starting a prime symptom. I attribute much of this to the poor quality gas of today and not specifically the oil being used. Preventative measures: run a can of Bombardier engine tuner through the engine each season. Using XD50 oil may also help, as it has a "carbon guard" additive. If you don't want to use the oil, get a bottle of their Carbon Guard and add a few ounces to each tank of fuel.

[LaveyT]

:cool:
Its weird , But when I run Carbon Guard thru my 225 H.O. It idles Sooooo much smoother with no sneezing or stalling. I really dont know why , it just works.

[j_martin]

:cool:
Its weird , But when I run Carbon Guard thru my 225 H.O. It idles Sooooo much smoother with no sneezing or stalling. I really dont know why , it just works.

The carbon guard probably off'd the carbon. JMHO:D

[Coupe9050lx]

where can i get some of that carbon guard?

[skatermike24]

Is that the same as Mercury Power Tune?????

[Action Dave]

A classic crossflow failure. Rings carbon up, preventing oil from getting to the ring. Top ring overheats and eventually cracks, then breaks into small pieces, rattles around the combustion chamber, denting the piston and head, then exits the exhaust. The lack of oil to the top of the piston will eventually cause it to overheat so much at high speed, that it will actually lock up in the block, then free up when it cools down and run again. My V6 locked up twice with same problem before it died. Hard starting a prime symptom. I attribute much of this to the poor quality gas of today and not specifically the oil being used. Preventative measures: run a can of Bombardier engine tuner through the engine each season. Using XD50 oil may also help, as it has a "carbon guard" additive. If you don't want to use the oil, get a bottle of their Carbon Guard and add a few ounces to each tank of fuel.


Good explanation. Carbon will build up in any 2 stroke motor. I have used engine tuner before and was shocked to see the amount of carbon deposits that came running out my exhaust. I use only 93octane and synthetic blend oil and still had carbon build up.

[mindblock]

When ware forms the ports become sharper and rings hit port. Some porters do a cheap job grinding the port angles,just a thought. and sometimes if its a motor from someone that drove it 1/2 throttle all its life ,forms a sleeve grove. Then when you wot ring hits a wall. or carbon

[Mark75H]

I think EMDSAPMGR nailed it, I see the same thing he does, including the place where a piece of the ring busted thru

[baja200merk]

these are not welfare motors :D

i had a looper that had 65psi in its best cyl! the other 5 were between 35 and 55 on 2 gauges. motors wouldnt idle under 1200 so i started it in gear and ran it around 6k all summer on my baja. needless to say that block is about junk unless you put .030+ bores in it :p i still have the block and all lol

[mindblock]

Monday 45% angle porting?

[jeepster21]

thanks guys for all the info.. i got the block back from being bord looks very nice, hopfully it will have more power so i can spin more than a 19 p prop this summer

[baja200merk]

port it :D

[jeepster21]

how big of a job is that? Should I have the heads milled down a little bit while im at it?

[baja200merk]

stock sucks :p

[mindblock]

You can pencil grind ports then polish them smooth . then buy new spark plugs and wot color test ..full wot then stop right there(dont drive around) and check right color specs..can play with gas/air screws if needed.

Not sure if i can link here...

http://ezinearticles.com/?How-To-Read-Your-Spark-Plug-in-a-Two-Stroke-Engine&id=170641

[baja200merk]

You can pencil grind ports then polish them smooth . then buy new spark plugs and wot color test ..full wot then stop right there(dont drive around) and check right color specs..can play with gas/air screws if needed.

Not sure if i can link here...

http://ezinearticles.com/?How-To-Read-Your-Spark-Plug-in-a-Two-Stroke-Engine&id=170641

what gas air screws:confused:

[mindblock]

depends on carbs ..4 strokes mostly 1 screw and 2 strokes most times have a air and a gas screw.

[lokinutz]

Forget running the carbon remover stuff. In my experience, the best way to keep from getting carbon build-up, is to run the motor wide open with the jetting way too lean (or with a huge vacuum leak). This will burn a hole clear through the top of the piston, causing complete rebuild. I try to do this a minimum of once a year. Twice a year if I feel lucky.

Please don't try to port your motor yourself. Honestly, if you want more power, save the money from the rebuild, and put it toward a larger HP rated factory powerhead/engine. If you are already commited to this rebuild, put it together, break it in, and sell it. Then, buy bigger.