SledNutZ

SledNutZ (http://www.slednutz.com/index.php)
-   Ski-Doo (http://www.slednutz.com/forumdisplay.php?f=36)
-   -   Scoring: Too much or fine (http://www.slednutz.com/showthread.php?t=6769)

Dirty_Harry 12-03-2013 05:48 PM

Scoring: Too much or fine
 
7 Attachment(s)
My pit crew and I (Mud) are in the process of rebuilding the top end on my sled. We were up in the air on the cylinders. Looking at these pictures, would you guys replace them or run them?

The Gerbil 12-03-2013 06:31 PM

Is it possible to get them honed and not have to replace them?

Dirty_Harry 12-03-2013 07:30 PM

I dont know. Not an expert.

Dirty_Harry 12-03-2013 07:31 PM

Mud and I already put the ball hone to them, but we were afraid to take too much off.

Rubi 12-03-2013 08:03 PM

Is that NicaSil, or a steel sleeve? $40 to get old school sleeved cylinders bored, $420 to get cylinders reNic'd.

I don't know if I'd let Mud's ball hone near my cylinder. I know everyone loves Mud's balls, but I like to keep my cylinder to myself.

flatlander_summit 12-03-2013 08:25 PM

If you can feel the scoring with your nails I'd have to say that you're going to need to throw new cylinders at it. I think it's probably time to hit up Doo, snowest, backcountryrebels, and the rest of the forums. You should be able to find something that you can use.

Gotmud 12-04-2013 06:47 AM

^^ Yes you can feel the grooves with your fingers, and that was after a good honing. It wasn't a ball hone we used, it was a spring loaded hone. I didn't like the grooves in it. I thought he should get more opinions on whether to bore them and swap his pistons for next size up, or get new/refreshed cylinders? I wouldn't use them in my machine. I realize it's more money than Harry wants to spend, but he also wants it done right.

stagesrt4 12-04-2013 08:34 AM

i like to use a flex ball hone

did you give it a nice long hone or just a glazing?

im not seeing much in the picture(but thats cause the pics blow balls)

Id say run it... if she runs well n compression is in spec/even then a lil scoring wont be big deal. Did you fry the last top end OR just doing a freshen up?

Gotmud 12-04-2013 08:58 AM

I realize you like a nice long hone Stagsex, but no we only deglazed the cylinder lol. Not sure wtf you mean by long hone lol. The whole point of a ball hone is to deglaze the cylinder, not bore it larger. Are you serious? ???

Dirty_Harry 12-04-2013 09:08 AM

Quote:

Originally Posted by stagesrt4 (Post 126053)
i like to use a flex ball hone

did you give it a nice long hone or just a glazing?

im not seeing much in the picture(but thats cause the pics blow balls)

Id say run it... if she runs well n compression is in spec/even then a lil scoring wont be big deal. Did you fry the last top end OR just doing a freshen up?

I didnt necessarily "fry" the top end, but the clutch side piston was real low compression. Piston was bad, but it "ran".

So flatty, would you run used cylinders?

Powersledder 12-04-2013 09:22 AM

If you can catch a groove with your fingernail it's time to re-nic. Yes you can run a hone at them for a while, but if it's that deep there's not much you can do.

I've ran plenty of used cylinders without issue. If the pistons are fine, then just get new rings.

Gotmud 12-04-2013 09:25 AM

The pistons aren't fine, he has new pistons. The scoring is deep enough if we tried to get it out with the hone, I'm worried the pistons would be too loose? Hate to see him ruin a set of pistons.

Powersledder 12-04-2013 09:26 AM

If you take enough material out to make the pistons loose....you've worn through the nicasil.

Pulled this from a MX forum

"The standard thickness on OEM cylinders is .002 inch whereas aftermarket platers like US Chrome use .006 inch. That way you can hone is several times before it wears though in areas like the top of the ring travel and around the exhaust port.
The typical life of a stock plated cylinder is about 100 hours or 5 piston changes.
Plating can be layered thicker but too much and it can become brittle."

Gotmud 12-04-2013 10:10 AM

I'm not honing the grooves out of his cylinders with the standard pistons. The grooves are too deep, I don't feel comfortable. I would get new cylinders, Harry already knows my stance.

Gotmud 12-04-2013 10:15 AM

1 Attachment(s)
Piston before we pulled the cylinder. I didn't take any pics of the piston after the cylinder was removed. I have more pictures of the cylinders but I can't see the grooves in them so didn't post them.

Ratstang 12-04-2013 10:35 AM

The pictures are bad and the bore is dusty but I see scoring that will catch a nail. I don't think I would use them, especially I if was going to hang on to the sled. Remanufactured cylinders are $200 + shipping.

Harry what pistons are your going to run, Oem, aftermarket, Ebay topend kit for $170 shipped? I would be tempted to stick a Ebay kit in it to see what happens. You could monitor compression and look through exhaust for piston scoring.

Gotmud 12-04-2013 11:14 AM

Used SPI pistons, same ones I rebuilt the indy400 and RXL with. I liked them so recommended them.:poosy:

Dirty_Harry 12-04-2013 11:15 AM

Quote:

Originally Posted by Ratstang (Post 126063)
The pictures are bad and the bore is dusty but I see scoring that will catch a nail. I don't think I would use them, especially I if was going to hang on to the sled. Remanufactured cylinders are $200 + shipping.

Harry what pistons are your going to run, Oem, aftermarket, Ebay topend kit for $170 shipped? I would be tempted to stick a Ebay kit in it to see what happens. You could monitor compression and look through exhaust for piston scoring.

This is what I bought.

http://www.ebay.com/itm/290993852939...84.m1497.l2649

Powersledder 12-04-2013 12:02 PM

Looks like she ran a little lean.

Gotmud 12-04-2013 12:10 PM

Well looks like captain obvious chimed in lol.:pointlaugh:

The Gerbil 12-04-2013 12:17 PM

He does bring up a good point though. What caused it to run lean? No sense spending the time and money to rebuild it if the root cause of the problem hasn't been fixed.

OCR 12-04-2013 12:25 PM

From the pitting across the entire crown, my guess would be a coolant leak into the cylinder.

Gotmud 12-04-2013 12:50 PM

^^ Judging from the color of the piston I would agree. We intend to clean the carbs and make sure there are no clogged jets. There really wasn't much coolant in there either.

Ibreakstuff 12-04-2013 02:35 PM

FWIW there is no buildup of compression below the ports. Most of the scoring is even wit h and below the ports. I "think" based on the sucky pictures that the top 3/4 inch has no scoring? I say fuck it and run it.
In a perfect world, a whole new top end would be in order but dropping a g-note into it isn't what you want to do. The life expectancy will be slightly decreased and you're probably down 2hp but who cares.

Gotmud 12-04-2013 02:55 PM

Yeah I agree, fuck it Harry. Lets just do it once a year? RUN IT!! :woot:


All times are GMT -5. The time now is 08:24 PM.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2007 Slednutz.com