Who knows about funky engine noises?

[Yamaha Tri-Moto]

Hey guys. Been having trouble with a rattling noise in the cylinder i had the whole top end redone piston, bore, etc etc etc a few months back then i really started noticing this rattling noise. so i built the top end again with a new piston, bore etc. (not the same shop again) but i still seem to be hearing a rattle in the cylinder, it seems to slow down as i adjust the air/fuel screws but then it stals cause it idels to slow. maby im just being paranoid im kinda new to 2 strokes. also some instruction on adjusting fuel/air mixture would REALLY help me out. im havin a hell of a time finding the correct levels.

[RideRed250R]

could be your pipe, i know on waterpumpers the fmf fatty exhaust, will make it "ping" which will miss lead you to think its piston slap.... but if your top end noise is very loud, i must ask... did you check the gap on your rings? did you check your spark plug after riding it to make sure its not to lean? did you do a break in?
FIRST.... i know you dont have HONE down as part of your rebuild list... YOU MUST have a hone (x hatching) done to the inside of the cylinder to allow the rings to seat...
if you didnt do a break in and just RODE THE CRAP out of it... then it might be piston slap form the rings not being able to seat properly... if yes you did do a proper break in ... then.. you might have been leaning out your AFM (air fuel mixture) which would in the end let you burn up your rings... causing it to slap... so thats what i think from what your saying.... also, whats your oil mixture ? 32:1. 50:1, 20:1 as it all matters....
hope i helped
adam
i have my idle screw...
2 and 1/4 turns out....
also i would say to drop a c clip on the needle... or possibly go one up on a main jet...(only if your running to lean)
to tell... run the bike at full throttle... shut it off WHILE still giving it full throttle...take the plug out... if its a WHITE/gray color... WAY to lean... drop a clip on the needle and go up one on the main jet... should richin the mixture through out the board...
Adam

[Yamaha Tri-Moto]

yes it was honed , the rings were set and everything. i have not even realy ridin it yet it would make the noise as soon as i would fire it up for the first time. my oil is 32:1. i also know im running rich cause as soon as i touch the choke it dies but i cant make it any leaner cause it will idle realy fast and creep its also only out about 3/4 a turn. i have a feeling its all in my fine tuning, would the rattle maby go away if a ride for an hour or so iv only ridin for about 2 or 3 mins. by the ways its a yt175.

[RideRed250R]

air leak..... if it idles REALLY fast.... its a air leak... its being starved for fuel... well.... i could lean to go as far as to say... it pings Alittle because it hasnt seated the rings.... mayb.... so just ride it through a tank... if it still pings after half a tank.... it could be rod knock... in the bottom end
adam

[Unclediezel]

My 125 made the most God_AWFUl top end noises after being stored for 20 years and reassembled-----

Go down to 20:1 on the oil for 1 tank----It will be a smoke screen and a half--and it may run really trashy----But I bet once everytrhing is broken in and properly "LUBED UP" --your noise will decrease drastically----Pinging is a possibility---but if it were bad enough to cause that much noise---it would have trashed SOMETHING already.

[holmstrom]

Everyone is always quick to jump on the airleak bandwagon. Thats what they kept telling me it was. Crankseals was mentioned alot, turns out it was a dirty carb and petcock. There was a thread on here were a guys trike idled fast and it turned out that the piston hit the spark plug and shortened the gap, changed his plug and it ran fine. Mine also would have a racey idle just before running out of gas.

[trikesown]

hey man check the pipes * might have loose screws same thing happend to my 110 till i cracked the oil casing then unfortunatly it kicked the bucket there is my reply to that hope * get it back up and runnin they are good machines they should stay good and runnin