How effects rich/lean mixture to engine life?

[blamir]

Hello,

I wonder that, what is the results rich or lean settings for engine life? If i ride richer than default, my piston, rod, bearings life slould extend? Why i ask that, i changed needle and jets so my bike is going like a hell but it is leener than old settings. There are 5 gasgas here and all of them are running rich. They tell me, my settings will damage my engine if i use with this settings.
Needle: NECJ #
Mj 175
Iddle 42
Air 2 out
Sea level.

Thanks

[Zman]

What bike do you have? How does your spark plug look?

[blamir]

EC250R 2012 plug looks like a bit darker, not as caramell. With oem needle my bike was fooling plugs after 2-3 riding so i changed needle and jets. Right now it is going really good as before.

[Jakobi]

Too lean can cause damage due to excessive heat. Way too lean and you can melt a hole in the piston.

The bike will give you signs of this before it happens. High excessive racing idle that won't settle down after hard pulls. White ashy spark plug when checked after a hard pull. Pinging under load with poor throttle response - lacking power - and feeling weaker and flatter the longer you work it for. Really lean will hesitate and feel like its going to stall out/starv under load.

If its running stronger and making more power it could wear out faster than a less powerful engine, however you may use less throttle, less rpm, and as such extend life.

Note: my experience is that a lot of people jet much richer than required due to the old school, poor toleranced engines which were prone to nip up. The Gasser engine is pretty solid, and I have done some super lean pulls over time and as long as you read the signs and respect whats happening you will be OK. If it doesn't feel right, its probably not.

[n_green]

Running rich will not hurt an engine, in fact it will prolong the life of it to a degree as a rich running engine runs cooler and is getting more lubrication (or not, as if the combustion temps are too low the oil won't separate from the fuel and will just be spit straight out of the exhaust). BUT if it is overly rich then you will be fouling plugs all the time (which is something modern 2 strokes just shouldn't do) and when you do do the top end you will be scrubbing gunk off your power valve and cleaning your exhaust packing a whole lot more thoroughly then a well jetted bike.

A lean running engine will run hotter, have less lubrication going through it (maybe this depends on the type of 2 st oil used, ratios and the flash point of that oil) and can lead to premature engine wear - rings, bore, piston etc. If it is too lean there is always the risk of the engine nipping up as well.

A well jetted engine will make more power, with a better power curve, will run cleaner, won't foul plugs, won't spooge like crazy, and generally won't get too hot unless you are stuck on a snotty hill with nil airflow and abusing the hell out of it. Sure it will probably wear the rings a bit faster then the overly rich engine, but rings and pistons are a consumable and meant to be changed at certain intervals. So why wouldn't you jet the bet as close to perfect as can be and have a blast riding it until its time to change those consumables.

Unless your friends have more jetting experience then you and unless they are detecting a lean spot somewhere then I wouldn't worry too much about what they say about you damaging your engine by running jetting leaner then theirs (if your jetting is good and theirs is rich).