chimpy Posted December 5, 2008 Share Posted December 5, 2008 Hi, please help My 2003 XT600e has decided to start missfiring (sometimes doesnt fire at all) when accelerating from 3,200rpm or less. It also misses a beat when at a constant low rpm when riding under no load at a low'ish rpm. It only does this when fully warmed up. When it does cut out it takes about 10-20 seconds of cranking before it starts, wilst cranking it pops a bit. I have had a non standard exhaust fitted and jetted to match but i have put it all back to standard and it's still the same. Thanks for any ideas Link to comment Share on other sites More sharing options...
Moderator YamaHead Posted December 5, 2008 Moderator Share Posted December 5, 2008 It only does this when fully warmed up. When it does cut out it takes about 10-20 seconds of cranking before it starts, wilst cranking it pops a bit. Sounds like it could be a stator coil going tits up My XT showed these symptoms once.......& after learning the hard way .......the Stator was the guilty culprit. Link to comment Share on other sites More sharing options...
chimpy Posted December 5, 2008 Author Share Posted December 5, 2008 Sounds like it could be a stator coil going tits up My XT showed these symptoms once.......& after learning the hard way .......the Stator was the guilty culprit. Thank you, ignition is the sort of route i was going however when i call the local yamaha dealer to get a price for a coil (£46+vat ) he asked what the problem was so i explaned and he said there was no way this could be the cause as the fault would be there all the time, he said check the valve clearances and make sure the carb is clean. Well in my opinion it would be the other way round. Im a car mechanic so im not stupid, if there was crap in the carb the fault would be more likley to show all the time however like you say a coil or stator breaking down usualy shows itself when hot to start with. Im unsure why the valve clearances would matter unless they are miles out but he being the yamaha dealer should know so i didn't argue, i will do as he said tomorrow and see what happens..... Link to comment Share on other sites More sharing options...
Moderator YamaHead Posted December 5, 2008 Moderator Share Posted December 5, 2008 he said there was no way this could be the cause as the fault would be there all the time, he said check the valve clearances and make sure the carb is clean. Typical Dealer mentality Anytime you have firing issues ONLY when the motor is hot........Money on it, it's got to do with the Ignition. Granted, Stator's, CDI boxes & primary coils are not cheap ........but @ least they're easy to swap out. Link to comment Share on other sites More sharing options...
SplinterThumper Posted December 6, 2008 Share Posted December 6, 2008 Hi, please help My 2003 XT600e has decided to start missfiring (sometimes doesnt fire at all) when accelerating from 3,200rpm or less. It also misses a beat when at a constant low rpm when riding under no load at a low'ish rpm. It only does this when fully warmed up. When it does cut out it takes about 10-20 seconds of cranking before it starts, wilst cranking it pops a bit. I have had a non standard exhaust fitted and jetted to match but i have put it all back to standard and it's still the same. Thanks for any ideas Hello there, well i'm sure the guy's who have alraedy replied are pretty clued up bikers and there reasons are good. I had a problem like this with a Honda 400/4, the fault was only down to the spark plugs of all things. 2 of them were missing sparks when the motor was warmed up and under more combustion pressure. Also if the HT lead is at fault i found out that when the motor has warmed up it can cause 'leakage' sparks to 'track out' from the lead to other area's of the bike, mostly arcing out to the frame or cylinder head. I suppose you only need a miss fire or 2 together to cause cutting out on a big single, bares a thought. A test i did was to fire up the bike at night on my really dark back garden and wait to see if there's tracking , arcing from the HT lead. I also found out in time that the resistor plug cap can go faulty too. Cheap things to replace are the plug and cap and then check the HT lead as i said above. A good quilaty 8-10 mm bore tubeing won't go a miss over the HT lead to solve a tracking problem. Just my expirences in this. Cheers Splint. Link to comment Share on other sites More sharing options...
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