Burned Up My 800 Help

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Rickb1b

New member

Mar 29, 2010

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• Jan 8, 2011

• #1

Well guys I committed the cardinal sin, I lent my machine to someone else. They were riding on hard pack snow, the hot light came on, they continued to ride until the coolant was gone and the engine stopped.

Needless to say I now have to get new pistons and cylinders. However here's my real question. The heads look a little funny, I've attached some pictures. The dome on both have a light brown color, however there is an area of discoloration, looks like the light brown has been sandblasted off. In the picture it is the shiny triangle area. Is this normal and is the head OK to reuse.

BTW its an 05 800 Switchback if this matters.

 

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Leardriver

Free Member

Dec 2, 2007

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Elizabeth, CO

• Jan 9, 2011

• #2

It's hard to tell until they are cleaned up. Heat can add all sorts of funny colors.

Clean them and even rub down the combustion area with aluminum or chrome polish so that you can see the actual metal surface. I've seen some pretty pitted up heads run forever.

I suspect you are ok, but without seeing the bare metal, it's tough to tell.

 

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Rickb1b

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Mar 29, 2010

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• Jan 9, 2011

• #3

Thanks for the reply. A few more questions. Assume there is a small amount of pitting, is it OK to polish these out. I'm concerned, if I leave a small pit it will create a hot spot and burn a piston. The reason I ask is, by the feel of it, I think I could pretty easily polish the dome to a smooth finish.

 

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boxster7614

Well-known member

Sep 20, 2008

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• Jan 9, 2011

• #4

You're fine dont waste your time, I've seen heads where piston rings have come loose and chewed them up and people put them back on and they ran just fine. You will get carbon build up on the piston and domes that has a rougher surface than that. I think all you are seeing is where the heat has burned off some of that build up on the heads.

 

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Rickb1b

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Mar 29, 2010

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• Jan 9, 2011

• #5

Boxster, you're spot on. I cleaned them up and all it was, is where the carbon build up burned off.

Thanks guys,

 

Last edited: Jan 9, 2011

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Rickb1b

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Mar 29, 2010

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• Jan 9, 2011

• #6

OK guy's my initial assumption was I needed two new cylinders, however as I'm cleaning them up I can only find one damaged spot.

Attached is a picture of the damaged cylinder, it's a really small chip in the coating close to the bottom skirt. I'm fairly confident all the other minor score marks will hone out. I've never worked with coated cylinders before, is this a big problem requiring a new cylinder or is it in an area which I can let it go, after I hone them.

 

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Nuge

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Feb 27, 2010

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WI

• Jan 23, 2011

• #7

I'd replace them. Looks like a bit of scoring to the cylinder walls. If you replace, make sure to compare height. I've gotten some that are quite a bit different. Last time I replaced with one from Millenium. Had to measure a few until I found one exactly the same.

 

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locknload

Active member

Dec 5, 2007

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• Jan 23, 2011

• #8

Clean the melted aluminum off the clinders with muratic-acid (SPELL) . Then have your local machine shop quickly run a hone thru them. That nicasil is very hard and I believe over 0.015 thick. You should be able to see at that point if you can reuse them. Ive seen way too many people buy new jugs when they should have spent just a little more time cleaning.

 

rmkboxer

Well-known member

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Nov 26, 2007

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Bonney lake WA

• Jan 23, 2011

• #9

I would get them renicked, way cheaper then new. or go to millenium and exchange them for like 200 ea and you will have them in a couple of days most likely

 

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clutch man

Well-known member

Sep 8, 2009

619

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43

La pine Oregon

• Jan 24, 2011

• #10

check bottom end too

with it getting that hot you should replace the seals in the bottom end and rebuild the water pump too.

Rickb1b said:

Well guys I committed the cardinal sin, I lent my machine to someone else. They were riding on hard pack snow, the hot light came on, they continued to ride until the coolant was gone and the engine stopped.

Needless to say I now have to get new pistons and cylinders. However here's my real question. The heads look a little funny, I've attached some pictures. The dome on both have a light brown color, however there is an area of discoloration, looks like the light brown has been sandblasted off. In the picture it is the shiny triangle area. Is this normal and is the head OK to reuse.

BTW its an 05 800 Switchback if this matters.

Click to expand...

 

Hardass

Well-known member

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Nov 26, 2007

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Troy Montana

• Jan 24, 2011

• #11

I will be sending some cylinders in for rebuild here soon if your interested just pm me Cost should be around 165 which would include any welding needed.