Raider center piston

[anapg77]

I had a lean seizure and the end of my riding season because i didn't richen up my setup in 50 degree air temp. (plus a 140 psi head)

What is going on at the center of this piston?
Is it detonation? I had pump premuim in it.

The rest look fine. Needless to say I am getting a new piston (for center cyl.) and rings for the other cyls. since the engine has about 25 hours.
snapfish

[ January 03, 2004, 10:16 PM: Message edited by: anapg77 ]

[Technical Support]

Can't see the pics, email them to me.

[anapg77]

Sent.

[Technical Support]

What you see is the start of a hole from running lean. I would go through all your carbs and pump.

[Mpeavler1]

Jami,

I lost your email addy or this would of been direct to you. If I was you I would run your top end richer if a drop in 20-30 degrees makes you run lean. I know the engine makes best HP at the 14.1 ratio but if you tune it to that extreme you are going to cost yourself a fortune not to metion always having to retune the thing if the clouds come out!! :( Also you should not have to change jetting for the 140 Psi head on it. More compression does not mean you have to richen it up a bunch. I usually run mine rich enough that it does not matter....really if you got 100-200 rpm increase from exact jetting you may gain 1-2mph but it is not worth new pistons !!!! [img]/graemlins/cwm27.gif[/img] Richen that thing up and let it just run a bit rich on the top end and have fun with it. Email your pictures so I can see them.

Cheers,
Mike

[Mpeavler1]

Ouch....my [img]/graemlins/cwm27.gif[/img] was on the wrong line Jami.....ment it to be after riding and having fun meant to put this one there :( after the comment on the piston!! Sorry bro.... :(

Cheers,
Mike

[Mpeavler1]

Jami,

I would just hone out the center piston...and leave the other bores alone. If you put in the new rings without a fresh hone you may not get the rings to seat real good...which would not hold compression good and that means ...less HP [img]graemlins/crying.gif[/img] I would just have someone take a hone through it for 10 bucks that way the new rings has the cross hatch to seat them well. How bad did the cylinder get scuffed up from the center one.....as far as when you hone it ...what kinda bore are you going to have? You may not get it cleaned up enough with a hone...its hard to see how deep the groves are in that piston...but you may need to get that center one resleeved if your at 1mm o/b already!

Mike

[anapg77]

Hey tech,

I was going to put fresh SBT rings on the other 2 cyls. after a ball hone job.

What are your thoughts?

Should I leave the rings alone without honing since they only have 25 hours and look OK?
Should I ball hone with new rings?
Or should I have honed by a professional with new rings?

[anapg77]

Center cylinder is just lightly scuffed.

It rubs right out with scotch brite. It should hone out very nice.

I was smart for once in my life and parked the 'ski as soon as it happened.(Well not actually)

It stuck once and shut the motor off. I didn't realize it was a seizure right away because it started right back up.

It stuck again during a high speed pass and I saw the seizure happening on the Tiny Tach but I was too slow to get out of it.

Then I got it stuck in the mud trying to adjust the high speed screws. Then I sucked up a bag in the intake. THEN I called it a day.