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8/18/2015
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GB
carl-h
8/16/2016 10:22am
8/16/2016 10:22am
I'm hoping someone here can help, I've been having a nightmare recently with my CR. 10 hours ago it had a full rebuild including genuine crank and wiseco piston. It's on a Lectron carb which has been running great for 6 months. Bike has felt great after rebuild until now.
All started after I took the flywheel weight off. Fired it up at home the day before riding and it had a slight hesitation or bog every now and then when blipping. I checked the needle in the lectron was seated right fired it back up and it was fine. It did it again the next day at the track after running for a few minutes. Then it was okay till I got out. 1 and a half laps in to my first session it died coming out of scorned at low revs. Fired straight back up and did it again just as I was coming to the track exit. Got it to the van and it had no spark and wouldn't fire back up. Got it home and it fired straight up.
The stator was sent off and found to be reading low so that was rewound, but the problem is still there. I replaced plug cap HT lead spark plug and cleaned the electrical connections. Running fine on the stand, went to the track and it died after half a lap but fired straight back up. Put my old carb on and it was the same so it rules out a feeling issue. Also, it's not the tank vent or feed pipe as the lectron has a clear float bowl which is still full when it cuts out.
Just replaced the coil, fresh plug and HT lead and it's still doing it.
I took the powervalve cover off with it running and that's working as it should even when the bike bogs/cuts out and closing at lower revs so it's not a problem there.
Only thing I noticed that's different is that it seems to be leaking a lot of splooge out the front where the flange sits on the cylinder. I cleaned it up Sunday and after running for 10 mins just its spewed enough out to run down the engine. But the bike isn't really running rich, I was wondering if a leak there could make enough of a back pressure loss to make it cut out? Doesn't explain why it's only intemittent though.
Does anyone have any ideas to try next?
Thanks for reading, sorry it's a bit long winded.
All started after I took the flywheel weight off. Fired it up at home the day before riding and it had a slight hesitation or bog every now and then when blipping. I checked the needle in the lectron was seated right fired it back up and it was fine. It did it again the next day at the track after running for a few minutes. Then it was okay till I got out. 1 and a half laps in to my first session it died coming out of scorned at low revs. Fired straight back up and did it again just as I was coming to the track exit. Got it to the van and it had no spark and wouldn't fire back up. Got it home and it fired straight up.
The stator was sent off and found to be reading low so that was rewound, but the problem is still there. I replaced plug cap HT lead spark plug and cleaned the electrical connections. Running fine on the stand, went to the track and it died after half a lap but fired straight back up. Put my old carb on and it was the same so it rules out a feeling issue. Also, it's not the tank vent or feed pipe as the lectron has a clear float bowl which is still full when it cuts out.
Just replaced the coil, fresh plug and HT lead and it's still doing it.
I took the powervalve cover off with it running and that's working as it should even when the bike bogs/cuts out and closing at lower revs so it's not a problem there.
Only thing I noticed that's different is that it seems to be leaking a lot of splooge out the front where the flange sits on the cylinder. I cleaned it up Sunday and after running for 10 mins just its spewed enough out to run down the engine. But the bike isn't really running rich, I was wondering if a leak there could make enough of a back pressure loss to make it cut out? Doesn't explain why it's only intemittent though.
Does anyone have any ideas to try next?
Thanks for reading, sorry it's a bit long winded.
Your problem is indicative of a loose flywheel wobbling around. the small metal strip where it's supposed to pass beneath the magnet on the stator will "miss" the magnet and cause misfires. It will be ok on the stand because the bike is flat and motionless. but on a track, it will cough and sputter when the flywheel wobbles.
But I trust you've tightened it. So that's probably not the problem. I'm typing this to jog the next guy's mind who reads this.
the only other solution is the CDI box itself, and if im not mistaken, those 02ish CDI boxes did have issues. Have you tried replacing it with a buddy's? That's what I'd try next. then when I got done with that, I would replace the rectifier that's on the left side frame spar under the rad shroud. those are the two things within the electrical system you haven't tested/tried, so go out in the garage and do it.
I bought the bike with the flywheel weight fitted and the box with the original nut in. I've just had a look at the diagram in my manual and it appears I'm missing a washer between the flywheel and nut. The flywheel felt completely tight with no movement by hand but do you think this could of caused the problem? I'm going to put the fly wheel weight back on and try it asap!
At the minute I don't know anyone with a Cdi I could borrow but my mechanic thinks he does. Do you know if the years are interchangeable? I'm guessing if so I'll be able to use 02-04 on mine? Also, is there any risk with me using someone else's cdi? I'd hate to break theirs too and have to buy 2 of them.
Well I'll be damned, your flywheel is installed incorrectly...imagine that...
Report back, let us know what you find. Good luck.
one more thing, when your flywheel is off, make sure your keyway isn't buggered. little halfmoon piece of metal that keeps your flywheel securely on your crankshaft.
The Shop
The mating tapers on the crankshaft and corresponding flywheel, held together by the flywheel nut, do all the securing.
Good luck mate.
I'm sure the cdi can be tested needing a reading of 0.7 volts while kicking the bike over. I'm not sure if this test will show any problems though as mine only plays up after a few minutes of running.
JW381, hopefully I'll get mine sorted soon. It's frustrating isn't it? I've literally put so much into this bike now. Every bearing has been replaced suspension is sprung and valved for me, SM pro wheels 2015 restyle kit the lectron carb 280mm brake kit. I've literally improved every single bit of the bike since buying it and now it does this to me. It's made me start considering the new crf a lot more now. It's a shame as this bike has been good to me right up till now and it probably will be once I've sorted it out.
I think cdi will be the next thing to try if the flywheel hasn't made any difference?
And that will probably be the next thing to replace. This will start really well pretty much all the time. First kick and it doesn't even need a proper kick really. When it's playing up it sometimes starts back up with a bit of throttle but instantly dies again, other times it will start and run fine for a few more minutes.
I've found a used cdi for £80 delivered and I may see if he has a regulator too and if it's not much get it thrown in so I can figure it out once and for all
But, I still wouldn't ruin out the stator. You had it re-wound, correct? Try swapping it out with a known good.
If it's still no good were gonna send the stator back for a bit more testing.
My hour metre reads rpm too and just to confirm its a spark problem it cuts down to around 6-700 when the problem occurs, even though the engine is obviously spinning faster than that. The fact it drops to 6-700 and not 0 until the bike actually dies means it's still getting spark albeit not enough I imagine? This doesn't really mean anything to me but someone else may recognise the symptoms?
and another thing if i remember correctly those models needed a resistor in the sparkplug or they had problems
I've ordered a rectifier
Pit Row
I must state that it sounds like a fuel issue, but a bad coil will do the same thing.
Paw Paw
I'm running a BR8ES plug. I assume the R means a resistor is fitted?
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