New Wiseco...BOOM?????

[fsuroxu]

I just put in a new Wiseco .060 over piston kit. Had the cylinder bored and honed according to the manual specs at .002 over piston size. It had an airleak in the base gasket, so I used Yamabond 4 and it sealed it up. Rode it down the street 2 or 3 times and everything was good, no weird noises, no pinging, no popping, everything seemed to be great. I came back down to the house on it and went to turn around into the driveway, and screeeeeccchhh!!!, it locked up on me!What the f*ck??? I pushed it up under the carport and kicked it one hard time and it started right back up! I let it idle for a second or two, blipped the throttle once or twice, no pinging still, no knocking, running good! Then it shut off with a quickness and won't budge for sh*t! Someone please tell me what I am doing wrong! Everything is bone stock except for the bore.

 

[brandoz28]

did you do a full break in? and did you let it fully warm up before actually riding it?

 

[super noober]

sounds like its too tight to me (giggidy) lol thats some wierd sh*t though

 

[royalt67]

Damn, locked it up. It is very important to warm it up properly (especially with a forged piston) during break-in. Sounds like the piston expanded faster than the cylinder.

 

[royalt67]

You might be able to free it by putting it in gear and rocking back and forth, after it has fully cooled. Chances are it's slightly fkd, but there's nothing to lose now. If you get it freed up, try a compression test.

 

[tyler1blaster]

you have to break in those new pistons other wise you WILL blow it up. sounds like it is time to rebuild all over again.

 

[fsuroxu]

Pulled it back apart and its not bad at all. The rings and cylinder are fine. the piston has one small score in it. Should the wall clearance be a couple thousandths more? When riding it, I never got over half throttle and never for more than three seconds. I was half ass trying to break it in. And yes, I let it idle for about 5 minutes before I ever took off on it. I don't understand it.

 

[Blaner]

mine did the same thing once, but didnt cause any damage amazingly! VERY VERY NB to warm it up PROPERLY also, what are you running in terms of oil? perhaps your premix is too lean? its most probably due to the clearance being tight, and mayb not warming it up enough...

 

[fsuroxu]

I run Lucas 2 stroke semi-synthetic. I think I am going to change though. It came apart really easy after it cooled down. How much does the piston expand at operating temp? Should I hone it out a little more?

 

[Awk08]

i'd go have it rehoned to 3-4 thousandths over, and we're not talkin about warming it up, YOU MUST DO THE REQUIRED 5 HEAT CYCLES!!!!!!!!!
start it and gently keep revving, no more than half throttle, till it gets completely warmed up, < hard to hold your hand on the head, then allow to COMPLETELY cool down, then repeat till you get to 5 times
then take it easy for a little while, some guys do 2 tanks of gas without extended full throttle runs ???
come on dude, you've been on here enuf you should have known to do a proper break-in of that piston
and do a leakdown test also, holeshotman sells them for a good price
and i'd also be wary of that stock oil injection, if that just happened to me i'd eliminate the injection and mix 32:1 with something better than lucas,
maxima super m is my prfered lube, but amsoil and klotz are good too

 

[Sandking]

That sucks the clearance must be too tight, that shouldn't have happened.

 

[scotj77]

LEAK DOWN! did you do it or skip it? and do everything awk said too. he's right you should know better if you didn't do the leakdown and proper break in. everyone here preaches that sh*t constantly

 

[royalt67]

Well, everybody else yelled at you, so I will just say I'm glad you didn't kill it.I:I

 

[Blaner]

Agreed...has anyone made firends using the "i told you so" line? you know how it is, guys, we all learn from or own stuff ups, no matter how much people warn us..

 

[fsuroxu]

I said it was bone stock but actually the oil injection is gone. The cylinder is already back at the shop, having it honed .003 more to make it .005 total. I am going to call Wiseco and ask them how much the piston is expected to swell just to be safe. Thanks for all the criticism and advice. I need to hear what a dumbass I am sometimes. It keeps my ego in check. HAHA!!!

 

[royalt67]

There should have been specifications for clearance on a little slip of paper in the Wiseco box. Then again, the shop should have known to put in an extra thousanth or so for a forged piston. I hope an extra .003 isn't too much....

 

[brandoz28]

.003 is going to put you at around .005 which is a TON......you need to talk to wiseco BEFORE having it honed

 

[royalt67]

I concur^^^^. For what its worth, my Wiseco motor stuck a piston like that last year. I figured it was lean, richened it up and never looked back. Of course at this time I was messin with the jetting so it wasn't totally unexpected. I didn't think about the fact that I probably had (and did) a bad crank seal causing a vacuum leak.

Message here, I guess, is don't take chances. Verify what your clearance should be and get it set correctly, leak test the motor before install, consider new seals anyway while you have it out, check your jetting as soon as you can after getting it going again. Being stock, it shouldn't need much, but switching to pre-mix can change your jetting just by changing your air/fuel ratio.

 

[xlSRHxl]

dude when i did my topend i went around my yard for 5 minutes just put putting around. let it cool down completely then did the same thing for ten then let it completely cool. got into 2ndfor 20 minutes and thats all i did then right after i went riding

 

[fsuroxu]

Come to find out, it is not the piston. It is somewhere in the bottom end. Could something in the clutch assembly lock up? By the way, I called and canceled the cylinder hone.