Search the Community

Request help for my kx250F just got my head back from the shop with the valve clearances set. installed and and timed bike started right up but it smokes more than i believe it should. The head was in the shop for a dropped valve.

OK here goes... Picked up an 04 200 EXC few months back, needed some work to say the least, wont go into detail of all the things i've fixed on the bike just the current and most present issue I cant seem to fix... it is smoking IE blue smoke/lots of splooge to the point that at the end of a few hour's ride, it's out the tail pipe, running down the back and dripping onto the swing arm/rear break caliper and blue smoking quite a bit. When I first got it, it smoked more and smelled like shit. So first things first went to the carb, I live on the Oregon coast (elevation/temp reference) it's old dirty/stained but inside looks good, came with jetting pilot-45, main-178 needle: no idea what brand guessing stock in the 3rd clip, adjusted the float height due to it leaking gas when bike was upright no tilt with the gas on, Bought JD jet kit and running pilot-45, Main-185 and Needle is blue 3rd clip (JD's recommend specs for my bike @ my attitude). I have also replaced my Inner crankcase seal twice (First time I thought I messed up the O-ring so redid to make sure). I've rebuilt the top end/new piston (same thing) cleaned the PV, NOTE HERE that the PV has some issues, it seems to work fine but the screw that goes on top of the cylinder, down into the PV/flap would not come out preventing me from removing the flap to clean it, however it move's/ function's correctly, and has minimum clearance on both sides. One of the PV cover bolts that also works at the exhaust spring holder, was over torqued at some point (impact driver prob), or a result in a hard impact, the hole the bolt goes into is flailed/jared open a bit, not bad, not in the way of any function/ PV Gearing/hinge, it is not needed for that area to be air tight as their is also a breather that goes out of the PV so will not result in an "air leak" or loss in Top end PSI.... anyway... it's still smoking.... quite a bit.. now the bike itself rides fine I feel, the carb does puke gas when tilted over slightly/ hard to start (kick start) after flooded (like all bikes tho) I don't have any stalling/low idle issues outside of user error on clutch control. Honestly outside of it smoking as much as it does I would think nothing is wrong with it.. I have also tried raising the needle Clip to 2nd clip and it changed nothing at all, not even feel of the bike/response and have a new Spark plug I have yet to put on the bike. I have also "compromised" the crankcase Gasket (new one in the mail) while I was putting the Crankcase back on but that should do nothing with the exhaust just a little gear oil leak not relevant but throwing it out there. So I am at a loss... I've been toying with the idea of getting a Lectron carb... However... would hate to drop $400~$500 and the issue still persist, if it's a jetting/carb/float issue that would fix it and improve MPH/fuel consumption Or something with the PV? but I don't see the PV causing that much smoke/sploogee... I've ridden the bike normally/hard and nothing's happened but I don't want to keep pushing it and possibly clip the bike. Any ideas? "Oh help me 2 stroke community you're my only hope"

Just bought a used 2017 Husqvarna FC450. It's my 1st EFI bike so I'm hoping someone can help me out with this issue. After starting the bike cold and idling for about a minute or two, it blows a puff of blue smoke from the exhaust pipe if I roll the throttle. It also does this if I stop to talk to a riding buddy on a trail or on the side of the track, let it idle, and then start out on track again. After revving it once the blue smoke is gone but riding buds have told me they smell and occasionally see a puff of blue smoke when following me - not a constant stream just a puff and then it's gone for a while. I'm talking to myself over trying to locate the cause of this as a leak-down test shows no issue. Bike history Bought used with 70 hours on it. Original owner had an FMF header and tailpipe on it which he kept. He sold it to me with the stock pipe. He never had it remapped for the FMF pipe Started it's life in Atlanta GA Now mostly ridden at sea level He told me he used mineral-based 10w-40 Yamalube oil. The manual calls for 10w-50 Ester-based synthetic - which the bike is now running. This is what I've tried so far: Leak-down test produced only a 3-5% loss. No bubbles in the coolant with the cap off No air leak at the exhaust pipe No leak at intake Barely, barely noticeable hiss when I remove the oil fill cap - but again not enough to lose any more than 5% pressure during the leak-down test. Wouldn't matter but checked the valve clearances while the valve cover was off. They were in spec. No loss of power No milky engine oil from a coolant leak No loss of engine oil as seen at the engine oil level window - never needed to add oil between changes Talked to someone who builds motors for a living and he said "all KTM/Husqvarna's do it especially when cold because the EFI delivers more fuel on startup as opposed to running at operating temperature". I guess I can see that but why does the bike blow blue smoke at operating temperature then if I pull off the trail or track for 1 minute to ask one of my riding buds something? I'm not letting it idle for minutes at a time. 1-2 minutes tops. Is this just normal for KTM/Husqvarna/4-stoke racing bikes?? Any help would be greatly appreciated! Former bikes where 2-strokes (CR250, RM125) and a 1993 DR350 which I could've let idle for 20 minutes an not seen blue smoke - but that was a carbed bike. I've always known if a 4-stroke is smoking blue it's burning oil and you shouldn't keep riding it. So I'm a bit concerned about whipping it around the track or taking it out a few miles on trails.