chippy Posted March 22, 2009 Report Share Posted March 22, 2009 Hi, my 2001 315 has developed a strange intermittant fault. After starting and running normally it will suddenly start running really rough, no power and won't rev. If I stop the engine and immediately re start, the fault has gone and it will run perfectly again. This sometimes happens after an hour or so of riding, but has happened almost straight after starting. It may not re-occur again for another hour, or it may happen after 15 minutes, but again if I cut the engine and re start the engine runs perfectly again. I have stripped the carb but found nothing amiss, I have taken off the mag cover but everything was ok in there. Any suggestions? Thanks, Chippy. Quote Link to comment Share on other sites More sharing options...
tt5th Posted March 22, 2009 Report Share Posted March 22, 2009 I would guess at it being electrical and would check the resistances are in tolerance on the Coil and on the Stator (or Magneto or whatever it's called). Quote Link to comment Share on other sites More sharing options...
wherry Posted March 23, 2009 Report Share Posted March 23, 2009 To me it sounds like a tiny droplet of water in your carb still. When you stripped it did you blow through all the jets and holes with compresed air or a can of carb cleaner? Quote Link to comment Share on other sites More sharing options...
chippy Posted March 23, 2009 Author Report Share Posted March 23, 2009 Thanks guys, I will re check the carb as that is easiest and see how it runs on Sunday at ESTC. Quote Link to comment Share on other sites More sharing options...
fastducs Posted March 23, 2009 Report Share Posted March 23, 2009 The fact that your problem is so intermittent makes the electrics a prime suspect. Check the kill button/circuit. Possibly a problem in the button itself, which could be intermittently shorting out. When you kill the ignition by pressing the button, you may temporarily relieve the cause of short circuit (corrosion?) Quote Link to comment Share on other sites More sharing options...
finn Posted April 6, 2009 Report Share Posted April 6, 2009 Hi Chippy, Did you ever get to the bottom of your intermittent running problem? I ask because I hand exactly the same problem on Sunday, mine ran fine 90% of the time then all of a sudden she ran flat, wouldn't accelerate, knocked and popped etc.. As soon as I stopped her and kicked her again she was fine? She did this about 5 times, usually during a section - very helpful! Any info would be of great help. Nick. Quote Link to comment Share on other sites More sharing options...
stuartcmorrison Posted April 19, 2009 Report Share Posted April 19, 2009 hi, was out practicing today on my '99 315 and had exactly the same problem, not running smooth, making the most awful noise and chucking smoke out the exhaust. turned it off, visual check over, nothing out of the ordinary, started up again and fine! did either of you guys (nick or chippy) get to the bottom of the problem so that i know where to start looking. cheers, stuart. Quote Link to comment Share on other sites More sharing options...
martin belair Posted April 19, 2009 Report Share Posted April 19, 2009 (edited) Chippy, I would bet a large sum of money that you have a non-resistor spark plug in your Cota. What plug are you running? Martin Edited April 19, 2009 by Martin Belair Quote Link to comment Share on other sites More sharing options...
stuartcmorrison Posted April 19, 2009 Report Share Posted April 19, 2009 Stuart, I would bet a large sum of money that you have a non-resistor spark plug in your Cota. What plug are you running? Martin Hi Martin, I've only had the bike for a month and the spare time I've had has been spent riding (probably about 9 hours) and not maintaining. I know the basic principle of how a 2 stroke works but not the detail, do you know what spark plug I should have and what effect a non-resistor vs restistor spark plug would have. Cheers, Stuart Quote Link to comment Share on other sites More sharing options...
martin belair Posted April 19, 2009 Report Share Posted April 19, 2009 Hi Martin, I've only had the bike for a month and the spare time I've had has been spent riding (probably about 9 hours) and not maintaining. I know the basic principle of how a 2 stroke works but not the detail, do you know what spark plug I should have and what effect a non-resistor vs restistor spark plug would have.Cheers, Stuart Stuart, the manual says NGK BR6ES. We also used the Bosch WR8DP. Both plugs have the "R" in the designation meaning Resistor. Some people will tell you that you don't need an R plug and that the R is for Automotive purposes, they are wrong. They symptoms described are exactly what happens when a non-resistor plug is used in the Monty. I am sure one more knowledgeable than me can explain it better, but I think that a charge builds up in and then is disapated when the bike is shut off. Then it runs great for a bit 'till the charge builds up again and so on.... Martin Quote Link to comment Share on other sites More sharing options...
jse Posted April 20, 2009 Report Share Posted April 20, 2009 Stuart, the manual says NGK BR6ES. We also used the Bosch WR8DP. Both plugs have the "R" in the designation meaning Resistor. Some people will tell you that you don't need an R plug and that the R is for Automotive purposes, they are wrong. They symptoms described are exactly what happens when a non-resistor plug is used in the Monty. I am sure one more knowledgeable than me can explain it better, but I think that a charge builds up in and then is disapated when the bike is shut off. Then it runs great for a bit 'till the charge builds up again and so on.... Martin Martin, I really agree with you. From my understanding, most of the newer CDI systems are "matched" to a resistor plug and the engines must use resistor plugs for a proper "talkback" to the electronic ignition. However, I'm not sure how the shut off/restart solves the problem, but I bet there's a MSEE or two out there on the forum that can explain it to us. As an added example, in some marine CDI systems, the engines require a spark plug with a special inductive type resistor (such as the NGK Z-type plugs). These types of ignitions systems produces less voltage and use of non-inductive type plugs can cause misfires and poor performance, so you can see that it's really important to follow the manufactuers recommendation as to plug type. Jon Quote Link to comment Share on other sites More sharing options...
stuartcmorrison Posted April 20, 2009 Report Share Posted April 20, 2009 Stuart, the manual says NGK BR6ES Thanks for that Martin, had a look at mine this morning and as you predicted it is a non-resistor BP5ES. Have ordered correct plug this morning, I'll let you know how I get on. Cheers, Stuart. Quote Link to comment Share on other sites More sharing options...
rdchair Posted April 20, 2009 Report Share Posted April 20, 2009 My 97 mont does this as well. It 'fourstrokes' and doesnt rev out. I was told it would be water and to put the choke on and run it as fast as it will go, this clears it (happened 3 times now) . I have cleaned the carb twice inbetween and I suspect its electrical, reminds me of a coil fault I had on a fantic years ago. It cost me a 3 yesterday, seems to kick in after heavy drop offs, maybe I should check for a loose wire? be interesting if someone finds the answer. Quote Link to comment Share on other sites More sharing options...
martin belair Posted April 20, 2009 Report Share Posted April 20, 2009 My 97 mont does this as well. It 'fourstrokes' and doesnt rev out. I was told it would be water and to put the choke on and run it as fast as it will go, this clears it (happened 3 times now). I have cleaned the carb twice inbetween and I suspect its electrical, reminds me of a coil fault I had on a fantic years ago. It cost me a 3 yesterday, seems to kick in after heavy drop offs, maybe I should check for a loose wire? be interesting if someone finds the answer. did you clean the choke slide? Quote Link to comment Share on other sites More sharing options...
rdchair Posted April 21, 2009 Report Share Posted April 21, 2009 no! will do now though. Quote Link to comment Share on other sites More sharing options...
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