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It finally got cold enough to get some time off work (yeehaw) so I got to pull the cover of my sled and engine I took apart in the late summer and really put my nose in there.
I'm a pour-in-the-oil guy on two strokes because of what I have seen inside and trust that it will make my engine happy. I expect very little wear when I pull one of my engines apart.
Oil does that for me but will not compensate for a mechanical issue. Finding a mechanical issue usually takes some experience and a lot of careful looking through magnifying lenses for us old guys lol.
My '13 has been set from new (4.5 turns out from factory on my sled) to burn 25 to 1 (with the 100 to 1 tank mix factored in) on good days and 32 to 1 on hot chocolate-cheese puff days.
I put 1700 miles on this "time bomb" lol engine and tore it down for a freshen-it-up for the new season. It ran with a head and pipe for about 1000miles and had a fuel controller (set-up rich at first then conservative after dialing) on from 100 miles (another big help for power and longevity IMO). I also was aware of my coolant temps spiking and cured that with the "28 dollar" lol mod (thanx TRS) mid season.
I know most don't discuss this after a tear down so I thought I would post what I found in my engine and maybe it would help people decide if oil is a good thing or not and what I think is a very important tip so you don't have to do it next year.
My stock pistons measured 6ish thou on one cylinder and 6 and a bitish on the other (no collapse there). My Fix kit pistons measured 5 ish and 5 and a bitish. I expected more difference after what I've read.
Did I need to change pistons? Yes, but not because of collapse. My pistons were damaged (ring land seal) and rings scuffed (not pitted or broken down or anything mysterious)) from poor chamfer in the ports. Nothing that looked like carnage, just visible signs (through those granny glasses lol) of why the ring seal was disappearing. Had they gone another 1000 miles I could see a ring starting to catch every stroke putting huge strain on the skirts and cylinders.
The PTO side was terrible on the boost port and MAG (funny it always showed richer on the plug and wash) was terrible on the right transfers and boost port. I've seen worse from the factory but not often. So I don't know if this is the norm on the Poo cylinders.
I believe if I had not broken in the motor gently (helps with stuff like this) and ran high oil ratio from min. one. I would have started this process of destroying ring seal earlier. Once the combustion pressure starts to bypass the rings piston collapse is a common issue.
This would have further aggravated the situation to the point of possible piston failure (the blow up thing).
I'm pretty sure if I did not chamfer the ports correctly the Fix kit piston rings would not have lasted any longer.
So burn that oil and break it in easy until you do take it apart. Then give the cylinders to someone capable (because chamfer shape and thickness is critical) and have them chamfer your ports properly (instead of whoever on the assy line). The power will stay there for a lot longer this time. And ( a side benefit), port flow (power) is most critical in equal timing of opening and restrictions in the last .080".
This is my first time into this engine and not all will be the same but I'm surprised to not have read about this before. For my engine the fix kit would have been a book on how to chamfer different port shapes properly and a small rat tail diamond file and another set of stock pistons. Nickasil will never chamfer itself no matter how many rings you put through it. Feel them with your finger. If they feel at all sharp just think about what your ring feels everytime it passes.
If yours are bad you need to address it while apart. My block may be a good one! Chamfer of the ports is a critical part of two stroke ports for ring life, piston life, and power.
IMO if the ports were chamfered correctly from the factory I would have wasted my time taking it apart.
I'm a pour-in-the-oil guy on two strokes because of what I have seen inside and trust that it will make my engine happy. I expect very little wear when I pull one of my engines apart.
Oil does that for me but will not compensate for a mechanical issue. Finding a mechanical issue usually takes some experience and a lot of careful looking through magnifying lenses for us old guys lol.
My '13 has been set from new (4.5 turns out from factory on my sled) to burn 25 to 1 (with the 100 to 1 tank mix factored in) on good days and 32 to 1 on hot chocolate-cheese puff days.
I put 1700 miles on this "time bomb" lol engine and tore it down for a freshen-it-up for the new season. It ran with a head and pipe for about 1000miles and had a fuel controller (set-up rich at first then conservative after dialing) on from 100 miles (another big help for power and longevity IMO). I also was aware of my coolant temps spiking and cured that with the "28 dollar" lol mod (thanx TRS) mid season.
I know most don't discuss this after a tear down so I thought I would post what I found in my engine and maybe it would help people decide if oil is a good thing or not and what I think is a very important tip so you don't have to do it next year.
My stock pistons measured 6ish thou on one cylinder and 6 and a bitish on the other (no collapse there). My Fix kit pistons measured 5 ish and 5 and a bitish. I expected more difference after what I've read.
Did I need to change pistons? Yes, but not because of collapse. My pistons were damaged (ring land seal) and rings scuffed (not pitted or broken down or anything mysterious)) from poor chamfer in the ports. Nothing that looked like carnage, just visible signs (through those granny glasses lol) of why the ring seal was disappearing. Had they gone another 1000 miles I could see a ring starting to catch every stroke putting huge strain on the skirts and cylinders.
The PTO side was terrible on the boost port and MAG (funny it always showed richer on the plug and wash) was terrible on the right transfers and boost port. I've seen worse from the factory but not often. So I don't know if this is the norm on the Poo cylinders.
I believe if I had not broken in the motor gently (helps with stuff like this) and ran high oil ratio from min. one. I would have started this process of destroying ring seal earlier. Once the combustion pressure starts to bypass the rings piston collapse is a common issue.
This would have further aggravated the situation to the point of possible piston failure (the blow up thing).
I'm pretty sure if I did not chamfer the ports correctly the Fix kit piston rings would not have lasted any longer.
So burn that oil and break it in easy until you do take it apart. Then give the cylinders to someone capable (because chamfer shape and thickness is critical) and have them chamfer your ports properly (instead of whoever on the assy line). The power will stay there for a lot longer this time. And ( a side benefit), port flow (power) is most critical in equal timing of opening and restrictions in the last .080".
This is my first time into this engine and not all will be the same but I'm surprised to not have read about this before. For my engine the fix kit would have been a book on how to chamfer different port shapes properly and a small rat tail diamond file and another set of stock pistons. Nickasil will never chamfer itself no matter how many rings you put through it. Feel them with your finger. If they feel at all sharp just think about what your ring feels everytime it passes.
If yours are bad you need to address it while apart. My block may be a good one! Chamfer of the ports is a critical part of two stroke ports for ring life, piston life, and power.
IMO if the ports were chamfered correctly from the factory I would have wasted my time taking it apart.
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