Melted piston, other looks fine!

[Himay]

Shee' was running rich so I moved the needles down a clip, throttle was much more responsive everything seemed great. Hit the dunes today after about 15-20 minutes riding, it started to feel sluggish. I stopped looked down and noticed the cool head sticker was burning off the one side of the head, black goo and smoke came out from the head also. But only on the left side.

 

Got it home, tore the head off and the left piston is melted bad, the right hand one doesnt seem affected. I am planning on having the jugs bored and getting a port and polish done while im at it. What else needs to be done, this is my first ever ATV engine rebuild!

 

Below are pics of the melted piston and the non-melted, Im thinking that I had an airleak on the left side causing the destruction. If it was because of me moving the needle clip wouldnt both sides have damage??

 

left side:

 

Right side:

[wayfst]

no, one side will usually go first. the other side has a seizsure mark on the exhaust side. I'm guessing you were way lean all the way through.

[Ruko]

Any time you change your jets or needle you should do a plug check before riding. I have also heard when they're lean they run and pull really good... until they melt down.

[switchblade]

They always run the best right before they let go.

[Himay]

Okay well let that be a lesson to me on making sure its not too lean!

 

What exactly do I need for the rebuild??? Do i have to go all the way to splitting the case?

What needs to be replaced??

[AllMotor347]

I just bought my banshee a little over a month ago and the first night i rode it it did the exact same thing, I tore it apart and put a new top end in the thing and now shee's great, just watch your jetting and make sure you dont have any air leaks when you fire it up

[thegroup]

What exactly do I need for the rebuild??? Do i have to go all the way to splitting the case?

What needs to be replaced??

412004[/snapback]

pistons(WISECO! ), wirst pins, and ''c'' clip, all come with wiseco piston kits. id also go with an aftermarket head and billet water pump and aftermarket exhaust

Edited September 7, 2005 by thegroup

[Himay]

Already have pro design cool head, boyseen reeds, toomey t-5's Thats why I was thinking of getting them bored, and port and polish while its apart!

 

Any certain brand on the water pump??

[thegroup]

ModQuad kindof pricey, but works a hell of a lot better then stock

[pimpeinkc]

what size domes you run in the head? if they are below 20cc, you need to run race fuel, me and two of my buddys found out the hard way, piston looked just like yours, i now have 21cc domes just so i can run pump gas and not worry about melt down

[Himay]

Im thinking they must be 21cc domes because I have been riding it hard all summer with no problems except it seemed to be running rich. Always ran it on Chevron Premium......

 

Another question the dome on that side has little pieces of the piston ring (assuming) stuck in it. Do I need to replace the dome, or can it just be smoothed out??

[Himay]

Well the jugs are going to be shipped to a local guy about 4hrs away where he is going to bore and port and polish them! I'll let everyone know how it rides afterwards, and if its good ill recomend him to people around here!

 

Im planning on just boring .020" over and using wiseco pistons. Im looking at a kit on ebay that includes the gaskets and bearings, but they dont call them pro-lites in the auction. Are there non pro-lite Wiseco's?????

 

Also needed to get the rear shock re-srpung and re-valved while the quad is down. Any suggestions??

[iceman]

Youll have to send your shock somewhere to get it serviced. Sending it to Elka or TCS or any other company like that is a good idea. If youre anywhere near Sandy theres a race tech center there. I took my dirt bike suspension to the race tech here in atlanta and its awesome now.