Okay so an update is in order so I pulled the jug off 2 days ago and what I found was that the top ring was seized. It seized in the form that the piston and and the ring actually became one, I dont know exactly what happened if I was running my mix ratio to lean or what. but it would seem that way, i always ran it 40:1. now i have a quick question and its how much play should be in the crank rod because it would seem like there is way too much play.
THANKS IN ADVANCE
RUBEN

 

Side to side play is ok and most do have a little of this. ANY amount of up and down play on the rod isn't ok and calls for a new rod kit if there is. 40:1 ratio should have been plenty as the oil pumps from the factory were set at 50:1 ratio on the 400s.

 

like i said opt it has me wandering i even would mix what i thought was rich. so idk so i should be good then with the side 2 side play well that's a relief to tell u the truth.
thank you
RUBEN

 

With two strokes anything at any given time can happen. You can sometimes track down why a ring may have stuck.For instance if it's on the exhaust side,air leaks or excess heat can possibly be a cause.If closer to the intake side,lubrication could be a problem. Either low quality oil or ratio too lean. Even too much or too little piston to cylinder clearance can do the same thing plus you can throw in things like cold seizures if engines haven't had enough time to warm up properly before wide open throttle.

 

it was actually in the middle OPT on the clutch side where the ring froze up, and that make sense about cold seizures.
THANK YOU
RUBEN

 

Happy to hear it was a seized ring...broken rings blow...broken skirts blow even more...


Bring it to a competent shop...they will tell you what it needs...or, if you were thinking of getting some porting/head shaving done, now is a good time since it's all apart

 

okay thanks
RUBEN

 

okay well i plan on taking my cylinder to hone tomorrow but i wanted to check with you guys about my rod play here is a video on it. :31-:35 is when i am doing the up and down motion.
please let me know if this is way too much play or not. as the machine shop in town is wanting to charge me 225$ to rebuild it my crankshaft or should i just get a used one off of ebay.
and lastly how are numara piston i went with this brand this time around mostly for 2 reasons 1stly because i wasnt that impressed with the wiseco one (since that was what i bought last time)and 2ndly because it cost me 50 and some change for the piston, rings,and the top end gasket kit. i had a 20$ voucher.
THANKS IN ADVANCE
RUBEN

 

Side to side is a little excessive. Can't tell with the piston on if the knocking is at the upper rod bearing or the lower rod bearing.Easier to check rod play by removing the piston and grabbing the rod down low by the crank and gently pulling up and down. Either way if there is any up and down play at the lower rod bearing or upper bearing and pin,the rod is shot. Don't get a used crank as you could get one that still needs to have a rod installed. Rebuild the one you have. Wiseco is the best piston out there. Costs more and worth it versus the cheap cast pistons.

 

Hard to tell...camera moving...feeling sea sick