pinging noise

[JosephGarcia]

pinging noise from cylinder while riding. i was looking around the web and i found this site http://www.off-road.com/dirtbike/tech/seizure/ which discusses 2 stroke engines, and a pinging noise related to running too lean. how can i fix this with my motor? if its normal for these please let me know.
previous owner did mention he made the motor lean

 

[gone_fishin]

are you confident working with the carb? there are 4 slots on your needle, & a circlip in one of them, you adust overall mixture by changing slots. there's pics and more info around here somewhere.

slot 1/top - lean
slot4/bottom - rich

also...you say you have a "broken in" engine...what oil & ratio are you using?

 

[JosephGarcia]

he says 30:1, so thats what im using. and he showed me those clips on the needle to change it, there are 3, and its on the farthest one. when the pin is vertical (as it would be when the engine is on the bike and in a normal position) its the one closest to the top of the bike.

should I change it to the middle one? and any recamendations for gas/oil mixture won't go unread, as i am new to this stuff.

 

[gone_fishin]

seems you're familiar, ok.

pre-mix is within the range of the different opinions here, that should be fine. low octane is better.

IF you're concerned about fuel mixture, it takes no time to try the different slots for yourself.

most peeps seem to have better luck in the midrange, my 70 runs best overall on 2nd from top of 4 slots. it's a safe bet you'll like the bike better on the middle slot.

BTW: are you already sure you don't have a leaking head or exhaust gasket? you've checked headbolts, exhaust bolts, plug, looked for oily signs of leaks?

 

[JosephGarcia]

I'll try the middle one then, thanks.

No leaks, a friend of mine who knows alot about these engines looked it over today for leaks or anything wrong, and its sound, save for the leaking carb problem I had, but was fixed in about 5 minutes.

 

[gone_fishin]

keep us posted 8)

welcome to MBc

 

[Guest]

Also, a leaking intake gasket will make it lean...if it still pings after you adjust the clip, double check your intake/carb gaskets.

 

[JosephGarcia]

checked the intake gasket. it seems kinda worn, how would i replace this?

 

[gone_fishin]

piece of cereal-box cardboard or black-paper/fiber gasket, goop up both sides with a gasket sealer.

oh yeah, & i remembered: the intake and exhaust flanges don't always arrive "true & flat" and this is one cause of early leaks. a flat file will easily take care of it.

 

[JosephGarcia]

tightened the intake sprocket, no leaks, everythings sound. changed the circlip to the second to the top notch. turns out there ARE 4, didn't look close enough last time, my bad. Haha.

So in cold weather what should I do to warm up the engine before I start riding it hard. I rode around the block at 10-15MPh. is this ok?

And maybe im not used to it, but something seems off about the engine firing, I'll upload a video to youtube so maybe someone here can tell me if its fine or what.