2smoke Posted March 12, 2019 Report Share Posted March 12, 2019 I swear this bloody bike is cursed! So, previously.. The ducati ignition had been causing me some hassle, eventually leading to me buying a complete Kokusan setup off a 2002 TXT. Now after a few issues with parcelforce, I finally got the new setup so like an excited child at christmas set to fitting it. It ran fine for about 20 minutes then started struggling at higher revs, so came back and fiddled. Now its weird.. Itll be hard to start, then refuse to run properly. Popping & banging, smoking and just wont rev. Also getting very hot very quickly! To me, its like ignition timing when it fails to advance/retard. But then start it up afterwards and itll run fine, turn it off and its back to running like *****. With the amount of smoke its chucking out I first thought crank seal & its burning gearbox oil. But that doesnt explain the backfiring and reluctance to rev, neither the fact that itll run right one minute. Feels to me like the cdi is playing silly buggers. Anyone had this before? Ive tried the basics, kill switch, plug, cap, coil. Fresh Super Unleaded, 70ml oil to 5L fuel. Quote Link to comment Share on other sites More sharing options...
2smoke Posted March 12, 2019 Author Report Share Posted March 12, 2019 Update, have got another cdi on the way to try.. Quote Link to comment Share on other sites More sharing options...
arnoux Posted March 12, 2019 Report Share Posted March 12, 2019 Looks and sounds like crankshaft main bearing oil seal (LHS) Quote Link to comment Share on other sites More sharing options...
lineaway Posted March 13, 2019 Report Share Posted March 13, 2019 7 hours ago, 2smoke said: I swear this bloody bike is cursed! So, previously.. The ducati ignition had been causing me some hassle, eventually leading to me buying a complete Kokusan setup off a 2002 TXT. Now after a few issues with parcelforce, I finally got the new setup so like an excited child at christmas set to fitting it. It ran fine for about 20 minutes then started struggling at higher revs, so came back and fiddled. Now its weird.. Itll be hard to start, then refuse to run properly. Popping & banging, smoking and just wont rev. Also getting very hot very quickly! To me, its like ignition timing when it fails to advance/retard. But then start it up afterwards and itll run fine, turn it off and its back to running like *****. With the amount of smoke its chucking out I first thought crank seal & its burning gearbox oil. But that doesnt explain the backfiring and reluctance to rev, neither the fact that itll run right one minute. Feels to me like the cdi is playing silly buggers. Anyone had this before? Ive tried the basics, kill switch, plug, cap, coil. Fresh Super Unleaded, 70ml oil to 5L fuel. Sounds like it is running fine considering you are burning tranny oil and losing crank pressure. Time to split the cases. Quote Link to comment Share on other sites More sharing options...
2smoke Posted March 13, 2019 Author Report Share Posted March 13, 2019 7 hours ago, lineaway said: Sounds like it is running fine considering you are burning tranny oil and losing crank pressure. Time to split the cases. It isnt though, it refuses to rev, lots of popping & banging. Start it up again and its running fine. I initially suspected crank seals, but its too random to be that I think. Plus it doesnt explain the heat of the exhaust within a few minutes of running. The excess smoke seems and smells like the carbon in the pipe burning up (like when you used to do a de-coke on older two strokes) Hence why Im thinking timing is over-retarded. Just a theory mind Ive had bikes with knackered crank seals in the past & they will at least rev out. Plus the plug isnt coming out oiled up, or overly dark.. Its a jonah! Quote Link to comment Share on other sites More sharing options...
b40rt Posted March 13, 2019 Report Share Posted March 13, 2019 If its running advanced, it will build heat quickly, causing crap it the exhaust to burn, hence smoke. As you said, swap cdi before going any deeper. Quote Link to comment Share on other sites More sharing options...
mcman56 Posted March 13, 2019 Report Share Posted March 13, 2019 Could the flywheel be loose and changing position? Quote Link to comment Share on other sites More sharing options...
thall1 Posted March 13, 2019 Report Share Posted March 13, 2019 A friend has a Sherco that had intermittent running issues... Wouldn't start without loads of kicks... Started fine when warm - usually, but also died at times and wouldn't rev out... After multiple carb cleans, base gasket change, fuel pump clean etc a new crank shaft seal behind the flywheel cured it Quote Link to comment Share on other sites More sharing options...
d2w Posted March 13, 2019 Report Share Posted March 13, 2019 Hmmm ... I'm just trying to learn from this thread (and not de-rail it). Doesn't the LHS oil seal actually keep the crank and flywheel/stator areas separate? Neither of those areas contain liquid oil. So if there was a leak wouldn't it be an air leak? And then wouldn't that cause the bike to run lean (with the added air into the crank) or just poorly (with less vacuum to draw in the fuel/air mixture)? And isn't it the RHS oil seal which separates the crank from the oil within the clutch/transmission? I could imagine a leak in that seal would draw oil into the crank and colour the exhaust as the oil would be combusted. Thanks for the education. Quote Link to comment Share on other sites More sharing options...
2smoke Posted March 13, 2019 Author Report Share Posted March 13, 2019 9 hours ago, b40rt said: If its running advanced, it will build heat quickly, causing crap it the exhaust to burn, hence smoke. As you said, swap cdi before going any deeper. This is my thinking, although retarded timing so the flame is still travelling down the pipe rather than giving the piston some downwards force. Happy to be corrected, but we seem to be thinking the same. The smoke smells like carbon 2t smoke.. CDI is on its way.. 7 hours ago, mcman56 said: Could the flywheel be loose and changing position? Checked that bit already 6 hours ago, thall1 said: A friend has a Sherco that had intermittent running issues... Wouldn't start without loads of kicks... Started fine when warm - usually, but also died at times and wouldn't rev out... After multiple carb cleans, base gasket change, fuel pump clean etc a new crank shaft seal behind the flywheel cured it This will start fine, just runs pants straight away! Quote Link to comment Share on other sites More sharing options...
2smoke Posted March 13, 2019 Author Report Share Posted March 13, 2019 2 minutes ago, d2w said: Hmmm ... I'm just trying to learn from this thread (and not de-rail it). Doesn't the LHS oil seal actually keep the crank and flywheel/stator areas separate? Neither of those areas contain liquid oil. So if there was a leak wouldn't it be an air leak? And then wouldn't that cause the bike to run lean (with the added air into the crank) or just poorly (with less vacuum to draw in the fuel/air mixture)? And isn't it the RHS oil seal which separates the crank from the oil within the clutch/transmission? I could imagine a leak in that seal would draw oil into the crank and colour the exhaust as the oil would be combusted. Thanks for the education. Yeah pretty much spot on. If the LHS seal has gone the bike will run lean (due to the fuel/air mix going to pot with all the air being sucked in past the seal). Symptoms usually include hard starting, high idle, overheating & eventually melting piston(s). RHS seal failing means it will just smoke like buggery, run like crap but will rev out & usually clears itself. I had an RD350LC (still got it funnily enough..) with knackered seals, tootle through a village at 30mph, get to the NSL sign, give it some beans and it was like a forest fire behind! Quote Link to comment Share on other sites More sharing options...
scarboroughbeta Posted March 13, 2019 Report Share Posted March 13, 2019 Good evening I've recently had the same problem with my 2007 beta rev 3 . It sounded exactly the same and smoked the same . I checked threw all the electrics . On the cdi i found a bared wire which I heatshrunk and taped . I also found a loose wire from the block connector which connects the cdi to the stator . It wasn't hanging out of the connector as there is 2 wires in the block it was wedged next to the other wire until I gave it a gentle pull . I cut the block off and put new connections on and also heatshrunk them . Then the next problem was the wire leading to the coil was loose in the block connector so I cut that off and put new one on . I also cut a tiny bit off each end of the spark plug lead to ensure good contact. Put new spark plug in and cleaned spark plug cap out with contact cleaner . I've rode the bike 3 times since this and it hasn't missed a beat . It would start fine but just back fired and popped at quarter throttle . I'm unaware of which part sorted it as I did the things I mentioned in one night but they were all things that obviously needed sorting. It was all worth a try before ordering a cdi which I put the problem down 2 . All I can say is check every connection 1 Quote Link to comment Share on other sites More sharing options...
lineaway Posted March 13, 2019 Report Share Posted March 13, 2019 The gasser feeds the mains with transmission oil. Not two stroke oil. Nothing like a Beta. Quote Link to comment Share on other sites More sharing options...
d2w Posted March 13, 2019 Report Share Posted March 13, 2019 Thank you for that critical bit of knowledge. I found this related useful thread: https://www.trialscentral.com/forums/topic/57493-crank-bearings/ Quote Link to comment Share on other sites More sharing options...
scarboroughbeta Posted March 13, 2019 Report Share Posted March 13, 2019 Sorry didn't realise that lineaway. Quote Link to comment Share on other sites More sharing options...
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