Damon367 Posted October 1, 2019 Near the end of this season my klx125 started to smoke a bit. I just took apart the top end to find an excesive amount of carbon build up on the top of the piston and head. I was surprised as the bike runs fine besides the small amount of smoke. Bought the bike used last year and this is the first time I've had the top end apart. Any ideas of what could cause this build up??? 1 1 Share this post Link to post Share on other sites
bweighmaster Posted October 1, 2019 Whar year bike ? Looks like it has been burning oil for a while ... install rings in cyl. And check end gap .... could have been just re ringed ? Mic. Cyl. Bore ...... new to you ? Or original owner ... Share this post Link to post Share on other sites
Fore-50 Posted October 1, 2019 Holy! i didn't think that much carbon build up was possible. ? 3 Share this post Link to post Share on other sites
Damon367 Posted October 1, 2019 9 hours ago, bweighmaster said: Whar year bike ? Looks like it has been burning oil for a while ... install rings in cyl. And check end gap .... could have been just re ringed ? Mic. Cyl. Bore ...... new to you ? Or original owner ... Bike is from 2004, just got it at the start of summer so yeah for all I know it could be 15 years of run time on that piston. I'm gonna measure everything today and see if anything is way out on it. Keep ya updated! 1 Share this post Link to post Share on other sites
mlatour Posted October 1, 2019 Worn / damaged piston rings and/or cylinder or, a bad intake valve stem seal. Share this post Link to post Share on other sites
donwann Posted October 1, 2019 (edited) Looks like there is adequate valve to piston clearance. No crescents from the edge of the valves protruding into the carbon. My guess would be valve stem seals as well. Edited October 1, 2019 by donwann Share this post Link to post Share on other sites
Rickf92592 Posted October 1, 2019 You know you don't need premix in that bike, right? 1 1 Share this post Link to post Share on other sites
Creeature Posted October 1, 2019 WOuld do stem seals for sure lmao 1 Share this post Link to post Share on other sites
Eric@ScottsPerformance Posted October 1, 2019 I am confused.... says he has a 2 stroke but shows a 4 stroke? Share this post Link to post Share on other sites
Rickf92592 Posted October 1, 2019 (edited) 12 minutes ago, Eric@ScottsPerformance said: I am confused.... says he has a 2 stroke but shows a 4 stroke? I think you're thinking of a KX125. And he's in the wrong forum. Edited October 1, 2019 by Rickf92592 Share this post Link to post Share on other sites
woods-rider Posted October 1, 2019 (edited) 2 minutes ago, Rickf92592 said: I think you're thinking of a KX125. He did post it in the Kawi 2 stroke section. I bet he is runnin pre-mix thinking that his bike is a two stroke. Edited October 1, 2019 by woods-rider 1 1 Share this post Link to post Share on other sites
Eric@ScottsPerformance Posted October 1, 2019 32 minutes ago, Rickf92592 said: I think you're thinking of a KX125. And he's in the wrong forum. Ahh I didn't see it say KLX 125. Share this post Link to post Share on other sites
capt justin Posted October 1, 2019 ive never seen that much Share this post Link to post Share on other sites
Robert Malcolm John Livingstone Posted October 2, 2019 On 10/1/2019 at 2:38 PM, Damon367 said: Near the end of this season my klx125 started to smoke a bit. I just took apart the top end to find an excesive amount of carbon build up on the top of the piston and head. I was surprised as the bike runs fine besides the small amount of smoke. Bought the bike used last year and this is the first time I've had the top end apart. Any ideas of what could cause this build up??? 1 Share this post Link to post Share on other sites
Damon367 Posted October 2, 2019 17 hours ago, Eric@ScottsPerformance said: I am confused.... says he has a 2 stroke but shows a 4 stroke? Never said it was a 2 stroke Just now, Damon367 said: Never said it was a 2 stroke My apologies I see where the confusion was, my bad 1 Share this post Link to post Share on other sites
Damon367 Posted October 2, 2019 17 hours ago, Rickf92592 said: You know you don't need premix in that bike, right? Yeah I know lol I've always just put regular pump gas in her, cant say what buddy before me was doing though Share this post Link to post Share on other sites
Eric@ScottsPerformance Posted October 2, 2019 2 hours ago, Damon367 said: Never said it was a 2 stroke My apologies I see where the confusion was, my bad Its ok- I am simple! Does the bike use oil? It might very well be a bad valve seal. Share this post Link to post Share on other sites
Layton Posted October 2, 2019 No matter what engine it is it has a really bad score mark on the side of the piston. You might want to check that out. 1 Share this post Link to post Share on other sites
shrubitup Posted October 2, 2019 Interesting power valve linkage on the left 1 1 Share this post Link to post Share on other sites
Smoking 2's Posted October 3, 2019 11 hours ago, shrubitup said: Interesting power valve linkage on the left You mean yours don't have that ?? 1 Share this post Link to post Share on other sites
