Does my bore look okay?

[flyingcr250]

it sorta looks to me that it has worn through the coating in a couple of places, is this possible?

thoughts........

[little.whittle]

Hows the piston?

[IIIRII]

Looks like varnishing to me, is it smooth if you run your fingernail across it ?

[flyingcr250]

Hows the piston?

doesnt look bad at all

[little.whittle]

How many hours did u do on that?

[flyingcr250]

Looks like varnishing to me, is it smooth if you run your fingernail across it ?

yea its smooth.... is varnishing bad?

[flyingcr250]

How many hours did u do on that?

85hours...........

[little.whittle]

:bash: poor thing haha:shutup:

[flyingcr250]

:bash: poor thing haha:shutup:

100 hours is supposed to be nothing for the 2T EXC's

[little.whittle]

wow! :shit: my one is recemended every 30-35 :confused:

[IIIRII]

Shit no, no worries, as long as theres no obvious grooves you can feel with your fingernail or anything else it should be fine, nikasil is really really hard so the bore should be sweet

[camchain]

Hey, nice clear sharp photos. I'm not an expert by any stretch but everything looks OK to me. You can't beat a good accurate measure up with a bore guage, take it to engine recon then you'll know. Common hot spot/seize spot apparently is the bridge on the exhaust ports, yours looks nice. You can see more wear down at port level (to be expected) but you can still see hone marks here and there, hopefully they are original. Search for my thread and photos of my grubby bore for comparision (about 9mths ago?).

Piston looks real good (but wot - no pic of front of skirt?) Danger has gotten super long hours out of his 200 pistons and your 300 much lower revver so longer lasting. I'd be tempted to run that for another 80hrs if it measures up OK.

I don't know how close the power valve is to piston on the 300s but on mine, piston/rings had been picking up carbon build up from power valve. I used CRC and a green kitchen pad to deglaze my bore. Don't mention the 'H' word. KTM wear limit on nicasil coating is only .025mm - very little to play with. Extremely unlikely to be any wear through the coating, it's super hard and tough.

After you give everything a real good clean you'll see the Nicasil coat runs into ports a few mil. The Nicasil is darker - looks a bit like a varnish.

[flyingcr250]

Hey, nice clear sharp photos. I'm not an expert by any stretch but everything looks OK to me. You can't beat a good accurate measure up with a bore guage, take it to engine recon then you'll know. Common hot spot/seize spot apparently is the bridge on the exhaust ports, yours looks nice. You can see more wear down at port level (to be expected) but you can still see hone marks here and there, hopefully they are original. Search for my thread and photos of my grubby bore for comparision (about 9mths ago?).

Piston looks real good (but wot - no pic of front of skirt?) Danger has gotten super long hours out of his 200 pistons and your 300 much lower revver so longer lasting. I'd be tempted to run that for another 80hrs if it measures up OK.

I don't know how close the power valve is to piston on the 300s but on mine, piston/rings had been picking up carbon build up from power valve. I used CRC and a green kitchen pad to deglaze my bore. Don't mention the 'H' word. KTM wear limit on nicasil coating is only .025mm - very little to play with. Extremely unlikely to be any wear through the coating, it's super hard and tough.

After you give everything a real good clean you'll see the Nicasil coat runs into ports a few mil. The Nicasil is darker - looks a bit like a varnish.

im gunna take it in to the bike shop tomorrow when i order my new piston kit, for the amount of hassel it is to get the head off, think id rather just put a new piston in. if you sw the rest of the bike youd see ive got a lot of work ahead of me lol

[camchain]

Ha, Ha, looks like you got a bit carried away with the spanners.
:gob:

[flyingcr250]

Ha, Ha, looks like you got a bit carried away with the spanners.
:gob:

just a tad lol, gunna do a bit of customizing, polished this and painted that, take a photo of the finished bike then wreck it all in the mud :scooter::scooter:

[Rupe]

thoughts........

Burn it.....

[flyingcr250]

Burn it.....

dont tempt me:shutup:

[cheese]

I was about to say WTF its an 08, what are you doing!!

[flyingcr250]

I was about to say WTF its an 08, what are you doing!!

thats how i roll son:wari:

gunna trick it up a bit, need to find a gnarly pipe too

[andy 101]

thats how i roll son:wari:

gunna trick it up a bit, need to find a gnarly pipe too

Got a fmf gnarly for my 250 xcw a few months ago, it will give ya mid range a real boost,be sure to get the carbon pipe guard as well,saves alot of dents, got mine from triplex moto, awsome service.

[That Guy]

look forward to seeing the bike back together....bore looks ok to me - I used to race RGV250s and often was replacing pistons bores etc - I'd put that bore straight back in after giving it a clean, it looks good to me (really need to run you finger over it to feel for any scouring but from what you've said it sounds fine). If you've taken the time to take the bore off I'd replace the piston and ring anyway, then you know you've got another 50 hours plus (100 on EXCs?) before you have to do it again regardless.

[flyingcr250]

look forward to seeing the bike back together....bore looks ok to me - I used to race RGV250s and often was replacing pistons bores etc - I'd put that bore straight back in after giving it a clean, it looks good to me (really need to run you finger over it to feel for any scouring but from what you've said it sounds fine). If you've taken the time to take the bore off I'd replace the piston and ring anyway, then you know you've got another 50 hours plus (100 on EXCs?) before you have to do it again regardless.

yea for the amount of stripping you have to do to get the heads of on these bikes its worth just putting another piston in:rockon:

[flyingcr250]

jsut been in to the bike shop, the mechanics reckon it looks sweet, but will need recoating after a couple more pistons

[Hazza]

im gunna take it in to the bike shop tomorrow when i order my new piston kit, for the amount of hassel it is to get the head off, think id rather just put a new piston in. if you sw the rest of the bike youd see ive got a lot of work ahead of me lol

Shit that looks alot like my crf atm aha

[flyingcr250]

all sorted, new piston is in, bikes almost back together,

i gotta say i was pretty impressed with the piston kit, it was all factory KTM stuff, with ample base gaskets, power valve gaskets, head gaskets, exhaust pipe orings, top end bearing, pin, and the rings were already installed on the piston. def worth the $300 odd bucks, but i now have about 8 leftover base gaskets. lol

[Pornstar]

horay for me, someone with a worse work bench than me.