KTM Owners Forum banner

How do you know?

1K views 17 replies 9 participants last post by  jmspear 
#1 ·
How would I know when the piston and/or rings will need doing on a 300 2t?

Iv done a compression test which was 160psi (which is obviously a good reading) as the bikes running fine.

What reading would I be getting if the piston/rings are getting ready for swapping?

Cheers
 
#3 ·
X2
Punch yourself in the dick
And just ride it m8
 
  • Like
Reactions: Bungie
#5 ·
Scott explain what it's doing m8 and then we can help you
 
#6 ·
I've been out on my 300 today with the king of tydesley and we both had jetting running issues which because of the heat in the woods were cured by turning the air screw out a quarter turn
So give us a detailed explanation and perhaps we can help m8
 
#8 ·
Yeah that's spot on Mitch mate, it's running sweet at the mo and want to keep it that way lol. Iv got no Hours to go by (like you normally would) so it's just another way of keeping an eye on it really. If the piston/rings 'went' I wouldn't know what it would run like, so just trying to look it up before it does if you know what I mean.

Basically (to me) its running fine, but what do I know, it could be running like a bag of dying cats.

The bike could have done 200 hours for all I know, so just trying to find another way out of seeing wether things are getting ready for the swap....

Cheers
 
#9 ·
If it loses power, becomes hard to start or starts to rattle you have two options. Pop the exhaust or head off and check the piston/bore.As long as you use quality oil,regularly clean air filters and warm it up before you ride you should have no problems. I have an '09 300 and I rag the snot out of it. Hth
 
#10 ·
for me i would put a fresh piston in now then you can log how many hours it does. that peace of mind is priceless! how pissed off would you be if it went bang first time out? it may have good comp from fresh rings on a shagged piston but if when you strip it you find the old piston is mint you have a nice spare dont you.£100 ish quid well spent in my book.
 
#16 ·
I haven't messed with the jetting since fitting the sxs pipe would that change things? I did a couple of miles turned it out and it got worse then turned it in abit and it was running sweet, it probably is wrong size because it isn't far from all the way in now.

Either way my forks are feeling sweet now !!!!
 
#17 ·
Cheers for that guys, yeah I could always fit the piston kit now and then the hours I put on it at least I know where I'm at;)

Yeah mine also felt a bit rich too today nipping to work and back, I know if I screw mine out a quarter itl start pissing it down and turn freezing cold ha but that's just my luck :dozey:
 
#18 ·
I would leave it well alone, you know what it feels like on now at 160 psi (which is good compression on a 300??) on the kickstarter, when it changes or gets easier to kick over it needs checking again or new rings / piston. It isn't going to go bang unless you over rev it massively, its a 2 stroke FFS. LEAVE THE ENGINE ALONE. Where are you going to stop? Have you looked at the crank seals? likely to be worn if you don't know history, will affect power if they are worn, (sucking in air, leaning the mixture, or oil from box, leaning mix again) how can you check, does she smoke, does the gearbox oil level go down - shit that's done it something else for you to worry about, if she starts and runs well with great power then ride it................ you are more likely to bugger it up trying to do preventative maintenance, read all the thread about setting power valve, no power after put back together etc, etc.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top