Two Stroke Motocross
Two Stroke Motocross Forum => Technical => Topic started by: cman on April 11, 2011, 09:26:58 AM
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First time out after a topend rebuild. Went through the break-in period for the first 30 min then when out trail riding. After a 20 mins the bike gently stalled and when I tried kick starting it, the lever was fully locked.
Could this be a clutch basket related issue? Please help!
2006 RM250 with Steahly Flywheel.
Any help would be greatly appreciated. Thanks!
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Unfortunately you are going to have to pull the top end. Any time the lever locks up is never good. Generally it means the top end seized or there is an issue with the crank.
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something sounds wrong if you only took 30 mins to do a break in process
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Thanks guys, I'm gonna start looking at the clutch side first and isolate the issue from there.
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I will really be surprised if it is a clutch issue. I know you are hoping for that as it seems easier, but it is VERY doubtful the problem lies there.
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I'd break it in using three (15 minute) heat cycles. Idle the bike for the first two cycles without twisting the throttle past 1/3. Do the same for the second heat cycle but don't twist the throttle past 1/2. For the third cycle, walk it into first gear trying not to pass 1/2 throttle and put around for a bit. Then either the day i go riding or the day before i find a nice flat area to walk it through the gears to make sure everything is working nicely. Let it cool one last time, then ride like a regular day (after warming it up of course).
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I'd break it in using three (15 minute) heat cycles. Idle the bike for the first two cycles without twisting the throttle past 1/3. Do the same for the second heat cycle but don't twist the throttle past 1/2. For the third cycle, walk it into first gear trying not to pass 1/2 throttle and put around for a bit. Then either the day i go riding or the day before i find a nice flat area to walk it through the gears to make sure everything is working nicely. Let it cool one last time, then ride like a regular day (after warming it up of course).
oh no not the dreaded heat cycle debate. If all i've done is replace a piston then i barely run it in at all, doesn't need it in my opinion. In fact i strongly believe that you can do more damage and impair performance by putting around like you say and not putting any load on the motor. without load you don't get a decent ring seal and strong possibility of excessive ring blow by.
And cman i really doubt it's a clutch issue because unless tou've had the cases split it's separate to the motor turning freely.
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When you put your top-end back on did you remember to put coolant in it?
EDIT: i would like to add that when you do find out what the problem is, that you post what it is.
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did you lubricate the rings and ring grooves, the wrist pin and needle bearing, and the cylinder walls with two stroke oil?
I do the 15 minute heat cycle as well x 3
with a oil fuel mixture of 26:1 the step down to 32:1
also did you retourque the cylinder and head bolts after your heat cycle?
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I'd break it in using three (15 minute) heat cycles. Idle the bike for the first two cycles without twisting the throttle past 1/3. Do the same for the second heat cycle but don't twist the throttle past 1/2. For the third cycle, walk it into first gear trying not to pass 1/2 throttle and put around for a bit. Then either the day i go riding or the day before i find a nice flat area to walk it through the gears to make sure everything is working nicely. Let it cool one last time, then ride like a regular day (after warming it up of course).
oh no not the dreaded heat cycle debate. If all i've done is replace a piston then i barely run it in at all, doesn't need it in my opinion. In fact i strongly believe that you can do more damage and impair performance by putting around like you say and not putting any load on the motor. without load you don't get a decent ring seal and strong possibility of excessive ring blow by.
And cman i really doubt it's a clutch issue because unless tou've had the cases split it's separate to the motor turning freely.
Lol I'm not a good enough mechanic to debate something like this but it's how I was taught how to do it and it works great for me. I got a long life out of my 125 and thats exactly what I want.
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When you put your top-end back on did you remember to put coolant in it?
EDIT: i would like to add that when you do find out what the problem is, that you post what it is.
Yes, I made sure and actually used engine ice. Unfortunately I've been down with no motivation to open it up right now so I can't update anyone yet. I'm hoping to get my spirits back by this weekend and let you guys know.
Thanks so much for all the advice.
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Come on cman. It only takes 5 minutes to take the head off to get an idea of what is wrong.
You can do it.
You can do it montage. (http://www.youtube.com/watch?v=VZ2HcRl4wSk#)
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When you put your top-end back on did you remember to put coolant in it?
EDIT: i would like to add that when you do find out what the problem is, that you post what it is.
Yes, I made sure and actually used engine ice. Unfortunately I've been down with no motivation to open it up right now so I can't update anyone yet. I'm hoping to get my spirits back by this weekend and let you guys know.
Thanks so much for all the advice.
Not to bust your balls, but I could take the entire bike apart in a couple hours. I'm with TM!....doesn't take much time to take the top off and have a look.
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What's a heat cycle? Is it a Yank thing? Here in Oz we fix it then wring it, no probs ;D
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I don't know why so many people leave their location blank. Someone cannot steal your identity just by knowing what state or country you are in!
Ok done ranting. My point is if we knew where you lived, maybe someone is close and can give you a hand. I am alway swilling to help people that are anywhere near Pittsburgh.
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something might have not been put back together properly maybe power valves kick shaft mechanism try them first i hope you ran it pretty oily when you were runing it in prefrebly mineral oil it would be hard to seize if you were just running it in and if you used essembly lube try the first two i wrote at the begining
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Come on cman just pop the top end off & let us know what's wrong with the ol' RM?? I would "unfortunetly" be willing to bet that the ol' girl seized up on ya. I personally don't think you gave it a proper heat cycle or lubed the piston & needle bearings enough.I've seen this happen before to alot of my friends anxious to ring their bike out after a top end rebuild. Not knowing if you installed the piston or someone else but was the circlips properly seated when it was put back together? ;)