Teardown has started....

[4bz1d2006]

Well, have started my teardown, not really happy with the way the valves and piston look. Glad I decided to do this when I did.

The piston is really dark all over the top, and the valves were really looking bad. two of them, half of whatever they are coated with, is completely gone.(Stockers) The cams look brand new. Haven't pulled the valves out yet. Have to get a spring compressor tomorrow.
Here's the pics....

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http://i161.photobucket.com/albums/t...nisToys013.jpg[/

[atv4life95]

What the hell is that all over the piston?

[TuckerHardRide]

Carbon build up.

[4bz1d2006]

I only have about 25-30 hours total on the machine since buying it in 2007.
I only get to ride once, maybe twice a year, right now unfortunately. I didn't expect things to look quite this bad I have to say.

[Basket Case]

keep in mind running it on tar instead off gas is not recommended nice catch tho, could have been expensive

[biggiej42]

Time for some new valves! My piston looked exactly like that when I took it out. I think it was running too rich for way too long.

[4bz1d2006]

I know, looks bad. Could I have maybe needed a hotter spark plug or something? The only engine mods I had up to this point were a Yoshi full exhaust, no airbox lid, and a twin air filter. The spark plug that was in it was a cr7e. It was within the recommended gap range. Is build up just fuel not burning completely enough? Crappy fuel? Both? the dealership where I bought the quad installed everything for me. Only recently have I begun to take on this project myself of checking it out and attempting to do the other mods myself.

[hmg9194]

No jets? I'm not sure what running lean will do to your engine (outside of Fing it up) but I do know it's not good for it.

Btw nice quad, I have the same one ^_^

[4bz1d2006]

They supposedly jetted it when they installed the pipe. It always ran great until just recently. If I can make it through installing this stroker crank and bbk kit into this thing myself, I'll never have them work on anything ever again.

[hmg9194]

You may want to check what jets they put in there/check your jetting with the spark plug, that might be the issue.

[4bz1d2006]

Update on teardown... I have gotten the motor out and on the bench, got the clutch cover and flywheel covers off today. Everything inside the motor looks brand new, except for that black-topped piston that I posted pictures of in the beginning. Everything came out fairly easy for the swingarm pivot bolt, and the lower motor mount bolt. Have a couple pics, but have to take a couple more before pulling the clutch and stuff to get the crank out.

[CFM-Z440]

Are those drops of liquid on the piston, or is that a tar like substance that is stuck there? Beyond that, the piston looks normal from what I can tell by the pics

[yOGi420™]

If it looks like that, is it possible to clean it up or is it beyond cleaning once its to that point? I think I may be a little rich now, and even though when I pull the engine apart I will be putting in new parts, I want to know if the stock stuff will be salvageable or if it would be junk if at the point of the one pictured?

[ltz4-rum]

The piston looks good considering the quality of today's pump gas. The black on the piston is normal and this would not be considered carbon build-up. (the liquid is from water left in the water jacket when he removed the head)

As for the valves...not quite sure! It's time for a set of good after markets with a great grind to go with it.

[CFM-Z440]

What makes everyone think that carbon on the piston makes the piston bad? Carbon build up is normal, and actually makes a nice thermal barrier to keep the piston cooler. The same goes for the head and valves as long as it doesn't get to thick.