My girlfriend was riding my quad it siezed and i got it running. I knew i needed a top end rebuild but you will never guess what i found. I pull the head off and the jug and the sleve is compleatly smooth but wait it gets better. Looked at my piston and the top ring has bent so i figured oh no big deal. when i looked at the front of the piston the whole front skirt is gone. Now keep in mind it siexed i got it running tuned it a bit and went riding FOR 1 1/2 HOURS !!! turns out she blew the front skirt off redlining it in first and the skirt droped down got pulverized and sucked up the bore causing it to sieze. Upon freeing it a few pieces got logged in the plug and beat up the edges of my piston a bit but i found at least 2 small pices in my exhuast. I ran all the time with a little more than 3/4 of a piston and shot the rest of the skirt out the pipe. Yamaha motors must be pretty D$#M good
Must read you will not believe this. I give yamaha props
- Thread starter ghoegler
- Start date
sooo... it siesed, your wailed on the kicker? to get it to fire and proceeded to keep riding it knowin that something was wrong, running the risk of, destroying, the crank, berrings, rod, sleeve, and head??.... not good man
yeah probably not but i was going to re do most of it any way so i was just like whatever i got another bottom end and i figured i already destroyed the top
yea saidly thas what happened to my bike not good man i f*ck my motor up by doing that now it needs a boat load of $$ to get er running good again
i had just gotten so lucky in the end run thats a once in a million that it managed to not even scratch my bore and only bent my ring on the way up all it needs is piston and rings
u might wana take the bottom end apart and check for any little bits of the piston other wise if therse anything in there ur gana f*** up ur bottom end next
How old was this top end?? cast pistons crack and come apart due to age/wear, not from 'redlining' plus you very rarely have a piston problem untill you begin aproaching piston speeds of 4000 fpm , and a stock/mild blaster motor is capable of no where near that. or the bore is so worn that the piston is bouncing around
That is pretty impressive that it still ran! I agree, you shoul tear down you bottom end the see whats left.
thats my next step is pulling apart my bottom end. yand the top end has never been rebuilt its still on stock bore and piston from the factor and its a 2000
a bore shouldnt be completely smooth. it should have a crosshatch pattern from the hone. if the crosshatch is completely gone to the point that it doesnt even look like it has a single scratch your cyl is probably really worn and maybe even needing bored but you may be able to get by with a hone job if it isnt worn too bad. but your definatly going to need that cyl honed and possibly bored along with the new piston and rings
definitly time for a bore, there is no way that thing is in spec after 10 years of riding. That explains why the piston came apart too.
Sorry for not being impressed with the destruction, even if you had a spare. Before getting a boner for breaking stuff you could have sold that worn out motor for cheap to some kid that really needs it.
I dont know how much the blaster rod is being stressed during hard riding but imo you should look really close to your rod. If there's a tiny nick in 1 rod of a v-8 race motor you change that rod without question. It WILL break at that nick. If blaster rods are over built than you might be ok. I'm just sayn, if theres a nick in your rod ask someone about it.
The Yamaha motor is great! I had a washer get wedged between the piston and cylinder and it was still running, poorly, but was running still. It did scratch my cylinder pretty good but the bore over I did really helped with hp. I would just rebuild the top end, you can check the bottom if you want. Peace.
