Melted piston New Blaster

[Woodzmen]

Hey I got a new blaster and I just melted the piston on it after 15 hours of riding. I got it with a stock carb and a dirty air filter and worn out reeds and a bad stator. I put new reeds boysean duel stage reeds. New pro filter on it and I bumped the main jet from a 220 to a 250 because it was a stock main jet. And 250 is what I heard most people ran after taking the cover off it. Can anyone tell me why I melted my piston on the exhaust side. I'm new to the motor tinker world

 

[joeak47]

Can you tell us more about your blaster... photos go a long way in helping. Does it have an after market pipe? What modifications are you aware of? Help us help you. We'll figure this out as a team. Welcome aboard by the way.

 

[Woodzmen]

It also has a reed spacer. I'm not home I'll send you a better picture of the fourwheeler later I think it's stock exhaust but not sure

 

[Markblaster]

WOW Red engine ahhhh. Its not a Honda. Paint that engine black or silver.

That piston is toast. How is the crank?

Download service manual.
http://www.blasterforum.com/threads...ervice-and-owner-manuals-free-download.17325/

Buy a leak tester.
http://www.blasterforum.com/threads/leakdown-testers.55015/

Both of them you will need.

 

[blasterboy91]

That's ruff dude. My vote is an air leak. Either that, or the main jet was to small/clogged. You said it's got about 15 hours on it, but what made you take the jug off in the first place?


the one pic it looks like the rings are not seated correctly. It could be my pic, but we're the rings set right?

Who did the bore/hone work?

Could be that the ports weren't chamfered before instal?

On the gas tank, look at the breather tube on the cap. Is it clogged? Take off the tube from the cap (if it has a tube). Open the petcock and see if fuel flows freely. Then, put your finger on the vent on top of the cap. Does it still flow? If it slows, or stops that could be your problem.

 

[blasterboy91]

Did you plug chop?

It also could be starving of fuel.

Did it start knocking or start to get piston slap?

If your piston to wall clearance and ring end gap are fine, I think it could be running out of fuel.

 

[speedyslyder]

you really should have washed that before taking it apart
also looks like red rtv was used on base gasket?. Don't do it get oem base gasket/or cometic and that's it.
no rtv silicone on base gasket.
leak test it after you have had the cylinder bored out and fitted a new piston.
or at least have a shop measure the cylinder for out of round specs before you fry another piston/rings.
so first step is=money lol
cylinder measured bored whatever fitted with TOP END.By a trusted shop
leak tested
proper jetting,basic i care about this engine
and proper break in

clean up the base gasket mating surface without getting it into the lower crank.

the quad has been neglected by previous owner know you need to pick up the pieces.
either way you look at it is going to be a expensive issue.
Either you fix it right or fix it RIGHT KNOW

 

[best]

Blaaster used to pipe in and say "Did you do a leak test and plug chop?"
There is your answer. A couple hours of works saves many hours and $$$ of aggravation.
Read up on "leak test and plug chop" in past posts.

 

[Woodzmen]

I didn't put the gasket sealant on the guy before me did and I didn't rebuild it. I took it off because it quit while riding and it had a compression test of 30

 

[Woodzmen]

Exhaust idk if it's stock or not. I got the blaster I rode it and it died after 15 hours of riding that's alll I know of it the rings are on right

 

[blasterboy91]

Well, it's a right bend exhaust. Dynoport? DMC? There should be something stamped somewhere on the exhaust.

I'll stand by my original statements of an air leak, or lack of fuel. I know it's late now, but you should have done a leak test BEFORE you tore it down. No worries tho. Grab a clymers manual from your local shop and enjoy the process of a rebuild. Only 3 things you'll need to complete this task.

1. Tool box of basic tools
2. Time alone in the garage
3. Beer.

 

[dirtysquared]

A 250 main with that exhaust didn't help matters. I'd suspect lean jetting and probably an air leak to be your killers.

The piston didn't grenade, which is good. But your going to have to do some rebuilding to get it back to running.

On a positive note, you have a really good exhaust and a pretty nice Blaster! Once you get the engine straightened up, you'll have a great runner.