85 250R Piston surface

[TravEX]

What should the surface of the piston look like through the spark plug hole? I got a flashlight and shined down in it, and the majority of the piston surface looks to be covered with black sooty junk, the only shiny surface I can see is on the right side (looking straight down in the riding postion) and is only the size of a dime. The motor is running fine, no problems. This is the R I got from 3leggeddog, and he said he hasn't touched the motor, so we really don't even know what's in there, or how long or if it's been rebuilt. He ran Blue Marble 50:1 and I've ran Blue Marble 32:1 in it, if that helps.

There is a little bit of 'soot' around the exhaust exit to the pipe, but not anymore than I would consider normal.

Thanks in advance,

Trav

[3leggeddog]

lean up your ratio.go 44-1or 40-1/is it foulin plugs,or runnin poopy?smokin alot?i had jetted it with the fuel ratio at 50-1,so the carbon build up could just be from the fuel ratio.

[crackshot]

2 strokes get carbon build up. Back in the day, removing head and cleaning carbon out was basic maintenance in motor manuals but with these new oils and their additives, they actually keep motors a lot cleaner.
Dogg is right, I would lean it up just a bit myself.

[TravEX]

My Amsoil Dominator oil is in, I gotta go pick it up, so I may switch to it, B how do you like it?

So lean up the pre-mix. I'll check the jetting after I run it a while with the new mixture.

Will that carbon clean outta there, or do I need to do something?

It was fouling alot of plugs, but the is my first R and am still getting used to there needs, hehe.

Thanks

[crackshot]

If its fouling, then its rich it sounds like. What type and number plugs you running in it? How do the plugs look that you removed out of there?

[TravEX]

Jetting wise, it will be getting more fuel at 50:1 than at 32:1, so I'll need to lean it up a little, right?

I re-read your post B, it really doesn't smoke that much. It feels to be running fine.

The coil, I believe is not doing well, and I am replacing it now with a new coil and plug wire and cap. The plugs foul after about an hour of riding. I've tested the old coil and the new one. Primary resist on the old : .2 new : .1 . Secondary resist old: 29.6K new: 7.54K . So, the old coil may not be putting enough charge to the plug. I have narrowed the plug gap, but haven't had enough ride time to tell if it helped.

[TravEX]

If its fouling, then its rich it sounds like. What type and number plugs you running in it? How do the plugs look that you removed out of there?

NGK BR8ES. The electrode is dark brown, and there is wet burnt oil around the bottom part of the metal surface of the plug.

[crackshot]

Yeah that sounds just a bit too rich, You have the correct plug but the gentleman that you purchased from would know more about that trike being he owned it and knows it well. He would be the one to take advice from. That's just my own opinion! :)

[TravEX]

Yeah that sounds just a bit too rich, You have the correct plug but the gentleman that you purchased from would know more about that trike being he owned it and knows it well. He would be the one to take advice from. That's just my own opinion! :)

:wondering I'm not doubting his advice. Just seeking a solution. We each have had the trike for only a few months. And thank you for your advice.

[Derrick Adams]

Trav, hows the air filter? Still clean?
Your jetting sounds pretty close to me, although a tad rich. If you want to run at 32:1 for piece of mind, just drop a main jet size. I never run anything lower than 40:1 ratio in any of my bikes. With todays modern oils, there just isn't any reason to do that. 50:1 is absolutey fine.

[3leggeddog]

when i got the trike i dropped 1 size on the main,and lowered the needle back down a postion.i also always rean it at 50-1.you should have no trouble with the amsoil,and 50-1.my bike has not held together long enough to judge the amsoil yet.i got a warped head issue,frown,so i dunno.blue marble is great oil,and when you switch,i am sure you will have to fine tune it a bit.they just burn different,good luck na dkeep me posted

[TravEX]

Thanks Derrick and B! The air filter is good and clean. I'm gonna put the new coil and wire on there, and run it at 40:1 for tank or 2 then 50:1 from then on.


Thanks again!

Trav

[TravEX]

I got it back together just now. New coil and wire, dropped a main size, went from 3rd to 2nd needle clip, and a fresh tank of 50:1 BM. After a warm up, it starts and runs much better than before! Thanks again for the help!