Jump to content
Sign in to follow this  

How does my piston/cylinder look?

Recommended Posts

Hi, its a 250 xcw 2013, stock.

 

What do you think?

 

vsj448.jpg

 

6fzg3r.jpg

 

23r7dab.jpg

 

15ed6xj.jpg

 

:ride:

Share this post


Link to post
Share on other sites

Its my first 2 strokes, 150h on it..

If it's 150 hours on that top end your long overdue for a new one. If it's still running then you should only need the cylinder honed by a machine shop that has the right tools, and a top end kit. Replace it before it becomes more expensive. New plating and possibly a new bottom end if your piston were to break from wear is a lot more expensive then maybe 150 for the top end kit and 40 bucks for it to be honed out by a good shop.

Share this post


Link to post
Share on other sites

The bike works great and it has enough compression, I do not notice a malfunction.

I was thinking of putting a new top end, without touching the cylinder.

Why do you say honing the cylinder?

Share this post


Link to post
Share on other sites

The bike works great and it has enough compression, I do not notice a malfunction.

I was thinking of putting a new top end, without touching the cylinder.

Why do you say honing the cylinder?

Because for the new rings to seat correctly, the cylinder needs to be very clean. It's only 20-40 bucks depending on shop price, they will clean out all the ports and all gasket surfaces, and make sure it's still in spec even though it may look ok.

Doing a top end without a hone is what defines a cheapo ;)

Imagine all the little crosshatches as pathways for the oil. When rings wear, they can clog those little paths so the oil doesn't transfer right and your new rings won't wear right.

Plus if your cylinder is out of round it would be a bad idea to put a new top end in. Chances are it's fine but for the 20-40 of them cleaning honing and checking, you can't deny how valuable it is.

Share this post


Link to post
Share on other sites

Do NOT hone nikasil plated cylinder ever. Whole idea is to maintenance your bike like it should. Keep your air filter clean and bike jetted correctly and change the piston much earlier. Your cylinder plating will last long time if you change the piston at time...

And second how do you see from those pictures plating?

Edited by KTMfinrider
  • Like 1

Share this post


Link to post
Share on other sites

It looks fine to me. The piston in my 300 went 9 years before needing replacement. The guy never changed the air filter, it was so dirty. There was dirt all over the intake side of the slide on the carb. Dirt all over in the airbox. Point is, my 300 still ran great with a f*cked up piston. 1ced781236fb5fc2eda22d5727d50d60_zps72da if I didn't need to change the cylinder base gasket, I would've never took it apart. Your piston looks stellar compared to mine.

  • Like 1

Share this post


Link to post
Share on other sites

I just did my 2010 xc 250 with 165 hrs.  The piston sides were clean so I wasn't getting any blow by. I checked  the old stock and new B piston clearance with a feeler gage.  They were the same. 

 

I ended up getting a used 2013 cylinder because the exhaust  flange was broken. I got the gasket kit first with a .5mm bottom but when I took out my old one in measured .65.  I put a hose clamp around the flange so maybe it won’t break again.  I’m thinking it was from the rocks or a crash.  It took me a while to get my pipe straightened out right.  The cylinder I got was honed and cleaned up some.  I have to send my old one back for the swap.  I will fire it up tomorrow after the rtv on the pipe connections dries

Share this post


Link to post
Share on other sites

If it's 150 hours on that top end your long overdue for a new one. If it's still running then you should only need the cylinder honed by a machine shop that has the right tools, and a top end kit. Replace it before it becomes more expensive. New plating and possibly a new bottom end if your piston were to break from wear is a lot more expensive then maybe 150 for the top end kit and 40 bucks for it to be honed out by a good shop.

He said 250XCW not 250sx. 150 hours on a 250 (xcw) isn’t too unreasonable. The piston doesn’t look too bad to me, does it? Sure it can use a top end but long overdue?

Share this post


Link to post
Share on other sites

im not sure some of these folks are qaulified to be giving advice 

 

you may want to have a competant shop thats familiar with plated cylinders visually inspect it, take a few measurments etc. its unlikely they will recomend honing it

  • Like 1

Share this post


Link to post
Share on other sites

He said 250XCW not 250sx. 150 hours on a 250 (xcw) isn’t too unreasonable. The piston doesn’t look too bad to me, does it? Sure it can use a top end but long overdue?

150 hours on ANY two stroke is too long in my opinion. I would run it 100 tops. Because at the price of a two stroke top end it's just not worth saving a buck on a top end only to have to put more into a bottom end or a cylinder replate. If I were going to run a piston that long it would at the LEAST get new rings at 75hrs if I planned on going for 150.

Heck don't some two smoker manuals suggest like a 14hr top end replacement? Now that's crazy but 150 hours is just too much. If he's worried enough to post pics of the piston, then that should say it's time for a new one.

Share this post


Link to post
Share on other sites

http://slavensracing.com/video/engine-videos/?tubepress_page=2

 

    Slavens racing has some excellent vids on a ton of KTM/Husaberg topics, heres one on cylinder maintenence. If the link doesn't work take the time to find it and check it out before you decide to hone the cylinder. I'm certainly no authority but I think the piston looks a little worn sure but I don't see signifigant blow-by yet. The skirting looks marked up a bit too but I didn't see any gouges. Given the hours on the bike, a new pistion and rings at this point would be good preventative maintenance to ensure the engine remains running strong.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×