blew it up today...

[02yamaturd]

dont kno how it happend cuz nothin to me really makes sense as to why this happened...i just got done puttin a 300 main jet in it, took it out for a spin and i was rippin on it and it just quit... then when i kicked it, it had no compression...whats confusing me is i wasnt holding it wide open for more than like 3-5 seconds, it wasnt running lean b/c i had just bumped it up from a 260 to a 300, there are no rips in the boot that connects the carb to the reeds/motor, so i kno it wasnt running lean..... i am a semi noob to 2 strokes but it just doesnt really make sense why it squeaked like it did and when it did, it was my first pass down the road so its not like i was constantly back and forth rippin on it...anhy suggestions why this woulda dont this...thanks guys, and heres some pics cuz pics make stuff so much better...I:I

 

[blasterfreek30]

do u premix the gas or is the oil injector still hooked up

 

[02yamaturd]

forgot to include that its premixed 32:1 with klotz oil

 

[Blasterdude27]

How old was it?
Did you plug the brass nipple on the carb were the oil injection used to suck oil from?

 

[blasterfreek30]

was it on an old or new bore?

 

[Little-J]

does the piston have marks all the way round or does it just have a mark when the picture shows it to be?

Also, does the piston have the worst of the wear on the 4 corners; ie the front on both sides and on the back on the two sides?

Did you warm it up good?

 

[blasterfreek30]

was it cold when u got on it....kinda looks and sounds like a cold seizure ( when its not properly warmed up and the piston expands faster than the cylinder)

 

[mystahagy]

Yep, my vote goes to a 4 corner seize, especially since that exhaust side still looks ok. Always let your 2 strokes warm up real gooooood before ripping.

 

[02yamaturd]

not sure on how old the bore is, i jsut got the quad a few months ago and the guy new nothin about it, yes it warmed up plenty b/c i rode it down my paps road real slow bc he bitches when i kick up dust (about a 2 minute ride), it only has scoured the piston wear the pin holds the piston to rod, and it scoured it on both sides, no scouring on the intake or exhaust port sides....i think it just got too hot b/c it was almost 90 today...thats my only guess...could be wrong though

 

[Little-J]

I vote some crap got in your engine and it scored your piston when it got brought up through the transfer ports.. Did you have your carb out when u did the jet change?

wipe your finger inside your transfer ports (the ones on the sides) and see if theres any foreign material there.. Wipe your finger over the intake port where the reeds sit and see if theres any unusual muck there.. Then look into your intake boot, (filter to carb) and intake manifold and take a peek for gunk..

 

[02yamaturd]

i was just lookin at it a little more and the scouring in the bore is actually aluminiun so im thinkin piston just got really hot and did this, does kinda look like a cold seizure but i assure it was warmed up...

 

[98blaster+4]

i know you said you warmed it up but a good rule of thumb i always go by is not to even rev it up until you cant hold you hand on the cylinder without instant burning, i usually let mine idle for about 5-7 minutes without riding , then take it easy for a minute or two after that. good luck with the rebuild

 

[Kennedy_Power]

The exhaust side and the intake side got hurt
I would suggest lean jetting and maybe a air leak
Jetting is very difficult, it takes years of experience do get it right...
I use air/fuel on four cycles and on two cycles I look at the power curve, spark plug on dyno runs to get it right...
Find out whats right will always lead to what's wrong
Like doing a leak down test to verify that there is not air leak...

 

[OConnor Racing]

The way the piston is scored on the intake side indicates you have a loss, or lack of lubrication. If you're running pre-mix, it's not the pump. Could the fuel be contaminated or tampered with? Did you suck in water from the intake. Did you clean the carb and leave cleaner in the bowl? Did you spray starting fluid in the cylinder? Something washed the oil film off of the piston / cylinder. Another theory is that the piston was damaged at an earlier time and it just picked yesterday to die. At any rate, you're going to need a top end kit and bore. This is also a good time to evaluate the condition of the bottom end.

 

[02yamaturd]

i was running 50:1 like 3 weeks ago and a 260 main jet, just 2 tanks of gas ago i switched to 32:1 and then yesterday i bumped it up to a 300 main jet, not saying it didnt get lean cause i havent done a leak down test yet....i think the blaster has been feeling a little sick for a couple days and yesterday it just decided to give up, between the 50:1 mix and the 260 main jet im sure one or both of those played a pretty big role in this...

 

[super noober]

i was running 50:1 like 3 weeks ago and a 260 main jet, just 2 tanks of gas ago i switched to 32:1 and then yesterday i bumped it up to a 300 main jet, not saying it didnt get lean cause i havent done a leak down test yet....i think the blaster has been feeling a little sick for a couple days and yesterday it just decided to give up, between the 50:1 mix and the 260 main jet im sure one or both of those played a pretty big role in this...

i bet you had a big airleak around the reedcage or carb manifold. with your mods a 260 jet dosent seem awful, mabey a bit lean. and to blow with a 300 from leaning out points to a big ole leak.

 

[02yamaturd]

i thought mabe a possible leak at the carb manifold or maybe the reeds but before i took it all out and there was no leaks, probly was a leak somewhere that i didnt see...

 

[smallz33]

everything has to die sometime.. It was your blasters turn this time.. BUT a blaster can be reborn.. Now us.. were f*cked

 

[02yamaturd]

everything has to die sometime.. It was your blasters turn this time.. BUT a blaster can be reborn.. Now us.. were f**cked

yea i knew it was gonna happen sooner or later, i was just hopin it was gonna stay together till winter so id have something to do over the winter, at least i got nice weather to strip it all down and reapaint the frame and plastics....i might have a found a whole motor ready to ride for 100 bucks, just gotta call the guy back and see if its really as good as he says it is....

 

[hotrodaj_2]

I think the 50:1 had something to do with it. It was slowly hurting itself and died when it died. Unless your racing, don't cut stuff like that back. Give it oil and fuel and it will live and run hard for along time.