no more b.s... heres the piston OUT of the bike

[Gani_riders]

How does it look?

http://s157.photobucket.com/albums/t41/Ty230/?action=view&current=topend014.jpg

http://s157.photobucket.com/albums/t41/Ty230/?action=view&current=topend015.jpg

http://s157.photobucket.com/albums/t41/Ty230/?action=view&current=topend016.jpg

The wrist pin bearing felt smooth and the wrist pin was mint ... Do you guys think this condition is "Bad"?

Also how do u clean the shat off the cylinder studs? Do you just leave the corrosion on there? and tthrow on some anti sieze or what?

[kingoddball]

Bad..

How did it get in such a bad way?

Looks like the piston has some bad scoring on it, it even looks like it been scraped away on the right side of your photo (16?)

Get the cylindar cleaned, honed and done professionally at a shop, dump that piston.

Mate, thats bad.

Get your Carb jetted and tuned up properly. Running way too rich by the looks of it?

Maybe evenm try a high/hotter spark plug?

NGK - 9EIX? (Irridium.. I dont remember the exact model)

You might also want to make sure your bottom end is ok.

[Gani_riders]

the bottom end has new bearings.. and i think its the fmf sst that facked the piston up so bad... my bike ran dirty rich with that pipe. I dont think it needs honing. my cylinder is mint... Im doing the whole piston and rings..

[2 stokes for life]

Why chance a $100 piston without a hone for $35? Its well worth the money and while you are there clean out the powervalves from running that rich.

[kingoddball]

Good news there.

You should always get your carb rejet and tunes with the change of an exhaust. Maybe run on less 2T.

I run 40/1 becauz I'm riding soft at the moment.

But I'd try use a hotter grade plug. NGK 9/irridium I think will burn hotter and burn off more of that crap.

If you want to do the work yourself, try get a guide and thin the fuel by adding more air and just for good measure change the reeds, dump some boyesen reeds in it.

[kingoddball]

Also check that your crank/conrod is aligned perfectly, it could also explain why you had such bad wear on one side. Anything can go wrong with bikes.

[Gani_riders]

the reason is cuz i put on a dented pipe and the area of the pipe that was dented was right at the first bend so it restricted a lot ..and i also ran a forest approved silencer..but im never going back to that shit. Jettting is spot on for a stock setup .. im pretty much at sea level with temps around 20degrees celcius.

Also is a hone really necessary?? if u need to see cylinder pics i have them too..

And im cleaning it all up and its gonna be as sexy as new after im done.. im just gettin started

[rusky]

looks like you kept the rings on that piston for wayyy too long which caused the piston to get scraped up like that.

Did you do the bottom end yourself?

[Gani_riders]

no the previous owner said he had all bottom end bearings done.. its weird cuz the wrist pin and bearing and skirt all look beautiful.. but the rest looks messed.. apparently the fmf sst supposedly melts the "crown of the piston" .. do u think that was the case for me

[kingoddball]

"Previous owners" say alot of things to get a sale.

It may very well have been done... 2 years ago.

Take the bike to a shop, tell them to tune it, hone and install the piston.

If you wanna do everything yourself, goto your local car parts store, tell them you want to home your cylindar and they'll give you a kit for your drill.

It'll probably cost about $25.

Put a hole in the dent of the pipe, get a tool in there and rip until the dent is out and weld the hole. Easy solution to a simple problem.

Throw the silencer away and get a stock or fmf power core or similar from ebay.

[Pincushion]

Piston was ran too long. Lots of blow-by and scuffing from it getting sloppy in the bore.

Have the bore measured and if its out of round then you'll need either a new jug or a bore & plate job. If its within spec, deglaze the cylinder with a scotchbrite pad and wd-40 as lube. Gently scrub at 45 deg and then gently scrub the opposite direction at 45deg until the cross hatch marks are clearly visible again. Put in a new piston & rings and then worry about tuning the carb once the engine is fresh.

[mtrablue]

bottom line, shoulda' changed that piston a bit sooner. take the time, do it right. clean the power valve. clean up the cylinder. if there is someone that you trust to hone the cylinder, do it. you can clean up the cylinder yourself with scotch-brite. just take some time and clean it up with great care. you don't want any of the abrasives from the pads left in the motor. do a search for info on dry assembley and cleaning the cylinder with ATF.

my 2cents on honing. there are dozens of differant grades of abrasives used in honing. some just for breaking the glaze on a plated cylinder. the old ball hone may be fine for an old harley but it is not the right tool for a plated cylinder. cleaning up the glaze should not remove any plating.

[harrperf]

Piston was ran too long. Lots of blow-by and scuffing from it getting sloppy in the bore.

Have the bore measured and if its out of round then you'll need either a new jug or a bore & plate job. If its within spec, deglaze the cylinder with a scotchbrite pad and wd-40 as lube. Gently scrub at 45 deg and then gently scrub the opposite direction at 45deg until the cross hatch marks are clearly visible again. Put in a new piston & rings and then worry about tuning the carb once the engine is fresh.

I would agree and say do not use a stone type hone you would most likely get at a auto store...

I personally use ball hones for nikasil...and they work well if you do it right.

scotch brit works well though, I would stick with that.

I hate the sst for the 250....I think it's junk.

Stock performs much better, and I have heard cases of piston crowns melting with the SST, but have not seen it in person....I can't think of anyone here who runs that pipe.

The piston sides certainly look scuffed, what premix?

And your hot spot underneath looks too big for my tasts...

Are you running amsoil of some sort? Rest of the piston is really clean....and I have seen only amsoil run that clean (it's full of detergants)

the "blow by" seen near the wrist pin hole is from the secondary powervalve....it happens on the best of bikes, but It is bad enough to make me ask...is the powervalve functioning correctly? Are the secondary ones stuck open?

[Gani_riders]

Sorry this experience is new to me where are the secondaries located is that the tube on the left side of the jug? I know that one problem i have right now is that in the right pv cover it leaks oil like crazy out of the seal..ive even replaced that seal and sealed the sh*t outta it

I have been running ipone for the time ive owned the bike

Also is deglazing and honing necessary? What do they do.. obviously deglazing deglazes the cylinder but what is the advantages of this?

[kingoddball]

The cyl will be smooth as ice, you wont have any issue of scratching, chipping, perfectly moving piston. you wont get oil/fuel anywhere other than right where it needs to be.

I had a scrape in the middle of my cyl, it worked, but it was just lacking something.

[adam728]

Also is deglazing and honing necessary? What do they do.. obviously deglazing deglazes the cylinder but what is the advantages of this?

A used cylinder will have a glaze left on it from oil, and buildup left from the combustion process. If you throw a new piston & rings in without cleaning this glaze you're rings will never break in correctly. This means lots of blowby, even with the brand new rings. There needs to be proper cross hatching on the cylinder when everything is new so that it can break in and seal up correctly.

[Gani_riders]

So scotchbrite and brake clean will do ?? what pattern do i wipe the scotchbrite in ?? just any direction?

[studboy]

So scotchbrite and brake clean will do ?? what pattern do i wipe the scotchbrite in ?? just any direction?

Re-read pincushion's post.

[1.21GW]

I keep seeing this on this forum that a 9 is hotter than an 8.....thats not what I remember reading on the NGK site....I'll have a look again.

[Markopolo400]

Your rings were left in way too long, and your engine is running very lean. Which is a recipe for disaster.