Ricco Posted January 8, 2018 Share Posted January 8, 2018 My Rs125DX is showing signs of needing a decoke. No problem removing the exhaust but when I tried to remove the baffle the first bit came off but the rest of it is stuck inside. Seems a previous attempt at this caused the baffle to snap, just where the thinner part meets the thicker part. Neither the exhaust nor the baffle are available to buy so it seems that I'll have to do the best with what I've got. I was thinking of pouring petrol or similar into the pipe then blocking off both ends and allow it to sit for a day or two. Then, with a hammer and broom handle or similar, knock the stuck bit out of the exhaust pipe. Clean the baffle up then repair it by welding. Any other ideas, or is there something more effective than petrol to use? Thanks for any replies. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted January 8, 2018 Moderator Share Posted January 8, 2018 And the signs of needing a decoke are? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted January 8, 2018 Moderator Share Posted January 8, 2018 39 minutes ago, Cynic said: And the signs of needing a decoke are? 1 Link to comment Share on other sites More sharing options...
blackhat250 Posted January 8, 2018 Share Posted January 8, 2018 59 minutes ago, Cynic said: And the signs of needing a decoke are? Pre- ignition,,,, Link to comment Share on other sites More sharing options...
slice Posted January 9, 2018 Share Posted January 9, 2018 Turn the exhaust upside down, whack a large potato over the end (this is your bung) then pour HOT water and caustic soda (mixed) down the other end, leave for a day at least. DON'T do this if your exhaust is aluminium or it will eat it's way out, then empty the crud out and flush with fresh water. You might have to do this a couple of times. If it still won't move then oxy acetylene torch up the end and set it on fire then run the oxy till it all burns off (yep that's right set it on fire..!) DON'T let it get this bad again..! 1 Link to comment Share on other sites More sharing options...
jimmy Posted January 9, 2018 Share Posted January 9, 2018 2 Link to comment Share on other sites More sharing options...
Ricco Posted January 10, 2018 Author Share Posted January 10, 2018 Signs of needing a decoke: The carb is standard as is the air filter. Plug is nice tan colour. Oil pump adjusted correctly. When cold, the engine 'burbles' terribly when I get to around 4k revs and won't rev through this. This is accompanied by quite a bit of smoke coming out of the exhaust. This eventually clears (a mile or two) but then, when I get up to around 50mph (6.5K) revs it smokes badly for 2 or 3 miles, before clearing back to normal. It's not using gearbox oil so I've ruled out the problem being bad oil seals. These symptoms may or may not be down to coking up but I didn't think it was a bad place to start! I've no idea when it was last decoked, I bought the bike last year, I've done 2.5K miles on it. By the state of the baffle and all this smoke I'm getting, it's probably been a fair while or maybe never! Link to comment Share on other sites More sharing options...
Moderator Cynic Posted January 11, 2018 Moderator Share Posted January 11, 2018 That my friend is a perfectly healthy 2stroke doing what a perfectly healthy 2stroke should. Its what they do. Maybe let it get a little warmer before moving off and use the gears to get through the smoke. If yours has a problem i have 3, 2 strokes in my garage need the same remedies. What is actually happening is:- A 2 stroke uses some of the exhaust gas as the charge, wonderful thing 2 stroke engine. Trouble is the oil condensates out when the engine goes cold and some will puddle in the cases (normal only actually a tiny amount). When you start up initially the oil starts to burn off, when you ride off and give more throttle the oil burns off roughly, this smokey rubbish gets in the way of the charge and gets spat into the front of the exhaust. As i said, its how they work, letting it tick over for a bit and not revving the engine before you switch off will help as there will be less residual oil. Link to comment Share on other sites More sharing options...
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