Engine seized twice

[LoRdMiCk]

I everyone 1st of all I'm new on this forum.
I have a blaster 03 with oil injection system still on..

I have my bike since oct 2014
It always had poor performance at WOT.. I used to run it with 91-93oct gas..
Last year I had my engine seized I was running around in a field was about 90-95° raining when it happened..


And this spring I changed piston/rings it was running exactly the same as before.. I run about 4 fuel tank and again engine seized while I was WOT... I was racing a straight line about 2miles then stop few sec everything was right and on my way back I did like 200feet then done..

I read a lot about jetting.. air/fuel mix plug chop etc.. I don't even know what is my jet size.. I'll check that tomorrow.. I have an fmf pipe but I don't know which model..

Anyone is got an idea of what could be my problem?
And any recommendation on oil to be used? Want something not too expensive.. and should I take off the oil injection and start with premix?

 

[LoRdMiCk]

That was the first time

And today..

I put the piston down and brushed the cylinder and mounted everything back and it start and run as good as before I won't leave it like this but I just tried it...

 

[Pj Uptmor]

Need a little more information. When u rebuilt the top end. Did you bore it and put new piston in it? Did u do a leak down test and what does the spark plug look like.
Is the tort system unplug.

 

[LoRdMiCk]

Need a little more information. When u rebuilt the top end. Did you bore it and put new piston in it? Did u do a leak down test and what does the spark plug look like.
Is the tort system unplug.

What is the tort system?
I changed the cylinder the piston and rings
The spark plug was white like the piston..
Finally no I didn't do a leak down test.

 

[Pj Uptmor]

You need to bore the cylinder and replaced piston and rings. Before you start the breaking in the new piston as ne ring. Get a leak down tester to see if you have any air leaks. This is reason for the plug being white.

 

[Larry's Shee]

WELCOME !!​

Now for twenty questions.
Did you put the pipe on or buy quad with it already installed?
Who measured for the new piston?
Was it fresh bore or old hole?
Did you check ring end gap?
Were the ports chamfered?
What brand piston?

List all other mods (modifications) (if you know)
Type of air filter, air box lid on or off, air box lid snorkel on or off, type of reeds, type of silencer.

TORS is safety system on carb that malfunctions and causes all kind of weird problems. It's a big unit on top of carb, commonly known as the "brick"
Hopefully you didn't get a cheap eBay/Amazon kit.

You have the classic lean burn down. Got so hot it melted the piston.

The main jet is inside the float bowl right in middle. There will be a tiny number stamped on the bottom.
I have a buck says it's a 220-230 (stock size)

​

https://www.blasterforum.com/thread...ervice-and-owner-manuals-free-download.17325/

 

[Larry's Shee]

https://www.blasterforum.com/threads/kor-engine-assembly-vids.51169/

 

[jbuckster07]

has anyone told you 2 stroke motors in general dont like 2 miles worth of WOT??? Your piston is melted!

Things got way to hot, your jets are off. From what I have read, 2 strokes get leaner and leaner the higher RPMS you give it, go if you bike is running lean to start with, then you tape the throttle open for 2 miles, sh*ts going to break lol..

 

[Larry's Shee]

Think of land speed record, Isle of Mann TT, track racing before AMA killed the 2s, Baja 1000, Paris to Dakar. It's all in the jetting.

Lean AFR burns hotter, the Piston is primarily cooled by the incoming A/F charge . There's not enough contact between piston and cylinder to absorb much, if any heat.