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2008 Kawi KX450f NO START

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Hello everyone i have finally ran into a bike that i'm very close to giving up on. I defenatly need any help on new ideas. So here is where im at. I have this 08 kx450f that i have what i think checked and double checked everything on. First of i bought it NOT running. I could not see any sighns of engine been torn in to or anything missing. Complete bike overall. Here is what i have done so far in the effort to get it started. First of i do have the service manual for it. I have checked "stator" its good with in spec, "crank positioning sensor" also good with in spec both with good resistance and clean. Completly have cleaned carb, bought a new  CDI, have unplugged kill switch, have reshimed intake valves, all are in spec, have done a leak down test and that was good. Cleaned the grounds of the ignition coil. Verified ignition spark with light tester and spark plug out to ground. Have cleaned all connections and even went as far as trying a new wiring harness. Have checked timing numerous times and all that is good. Have checked the gear selector switch and thats has good resistance in every gear. It apears that i do have the 1volt +- from the crank positioner, but i can not read much voltage when im kicking over from the stator only about 20ishhhvolts, from the expected 50ishh in manual but resistance is good and in spec and i have a good spark at the plug and i get random backfires with and without starting fluid. I AM PUZZELD.  I have read in other topics that the fly wheel may looses magnetism but this one will hold on to my screw driver when i put it on the inside of the wheel but not on the outside or on the bumps it has and not sure if thats how it has to be or not. ANY IDEAS ARE GREATLY APRECIATED!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Edited by ajchamp
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I have no experience with that particular bike, but from a generic engine perspective if you are getting backfires without starting fluid that tells me you are getting fuel and spark.  You have also verified that you have compression.  So I'm guessing you either have an ignition timing or cam timing issue.

Not much help, I know...

Doc

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That's what i was thinking also about the timing. I have gone as far as rotating timing 180degrees just in case someone previously messed with it but i got worse..i timed it back up on the compression cycle, lighned up the fly wheel mark at the engine plug also the timing marks on each cam level with the head, cam lobes pointing outward and cylinder on TDC. I also verified the 29 pins on chain from mark to mark all good their...i've heard of the main cam sproket moving out of place but i've kicked it over 100 and verified timing marks all over again and they are exactly where i put them..any ideas welcome!!!

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When you say - Completely cleaned the carb - did you dismantle the whole thing - making sure nothing was blocked ?

It does sound like timing and weird it would only backfire on starting fluid

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Midge, yes i diamanteled the whole carb and their was really nothing wrong with it. Sorry about the confusion, it will backfire with and without starting fluid...i can take the plug out and kick it and see some  gas come out the spark plug hole...Another question to anybody is can the stator still be bad if the resistance is still with in tolerance  but i'm only getting 20ishh volts at the leads instead of the 50 i believe it should have? Spark looks pretty good when kicking over.

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I had similar issue on two separate engines , one my generator which was  brand new, and 2nd my lawn mower. I know , i know, hold on..., in both cases it was the spark plug. Yes, I was getting spark but how do you know it is good. If you have not purchased a new spark plug one, you don't know for sure! Your starter fluid test is a good one to eliminate few things. My generator was brand new with a weak spark plug from the factory. Anyway..., this is my 2 c.

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joyhnye75.....I have tried 2 different new plugs on it, and have tested spark with the inline tester and thats how i'm looking at spark besides the old fashion way of holding spark plug to chassis and risk the shock. lol i am wandering that if their is a chance the woodruff key could of sheered from fly wheel and it throws the whole timing thing off all though i have no indication of that considering timing marks are not moving away from TDC. I just purchased the removal tool to inspect because i am pretty much out of things to check. I'm stumped on such a small engine. Also after reading the manual again i see that the stator checks out fine on the output and the resistance. Glad cause they are expensive. Thanx everyone so far for their input!!!

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Believe it or not the woodruff key sheering off the flywheel has happened to me on a very old German bike I had when I was 15yo. I bet none of you have heard of this beast , it is 1964 Simson kr51 made in East Germany, I had stripped it dowh, removed fenders, etc.. to make it sportier! :) lol... . We could not find parts so we had to make the key ourselves. 

Yes, check that!.. , you have done everything else.

Edited by joyhnye75
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4 hours ago, joyhnye75 said:

1964 Simson kr51 made in East Germany

Like this ?

StrV2_1964Schwalbek.jpg

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That's is defenatly a classic....i've seen the woodruff be damaged atleast 2 other times on different small engines but i just didn't have the puller to check this one, i have one on the way i will update after i check it. Thanx for the replies!!!

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Pull the spark plug and drop a screw driver or a long socket extension in the hole. Spin the engine over and verify that the TDC on the flywheel is actually TDC with the the piston. The screw driver or extension will obviously rise and fall as the piston goes up and down and you can verify where TDC is on the piston and then compare it to the mark on your flywheel. If they aren't the same you know you've got a problem with the woodruff key. If it has spark and won't fire with starter fluid I'd guess you have a timing issue

 

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Jevyguy....i will very the TDC with marks all over again...i'm pretty sure they are dead on from all the times i checked but it can't hurt to look again, considering i'm out of things to check..i'm really not expecting for woodruff to be bad but i'm checking anyways...i might even start tinkering with the timing and move it a tooth either way to see what it does.

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Maybe y unscrew the fuel screw and forgot to set to 2 turns or whatever it need to be? 

FCR carbs can be very finicky if the fuel screw and idle are not set just right. I had the same issues on my 06 until I dialed in the carb. Go JD jet kit, RD powerbowl and the ap mod and you will be amazed at how well it will start after that.

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16 hours ago, Midge said:

Like this ?

StrV2_1964Schwalbek.jpg

Yes, that is the one. Basically a bigger, heavy, gutless scooter. Nevertheless, I was the only kid in the neighborhood with a bike at that time, so I got very popular as I was letting anyone ride it : ) lol

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wes513v.....i will defenatly look over them screws again although you would figure it would atleast try to start with starting fluid...i will post what i find when i get home from work and check thanx..

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Well i got the fly wheel puller yesterday and had the chance to pull the fly wheel off to check the key way was not damaged and it was NOT, big bummer for me cause i was kinda hoping for that to be it...incase anyone is wandering the puller is a 24mm....i checked the cam sproket while in their and it was lighned up perfectly...the counter balancer dots are also matching up at 12 o'clock and 3 o'clock positions matching the mark on the sproket from main cam once it's TDC....also adjusted air mix screw on bottom of carb to 2 turns out and 1/4 turns at a time either way and still nothing....moved both intake and exhaust cams counter clock wise 1 tooth while keeping all other TDC marks the same and actually sounds a little more promising but still NO START ?

Edited by ajchamp

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Well i got the fly wheel puller yesterday and had the chance to pull the fly wheel off to check the key way was not damaged and it was NOT, big bummer for me cause i was kinda hoping for that to be it...incase anyone is wandering the puller is a 24mm....i checked the cam sproket while in their and it was lighned up perfectly...the counter balancer dots are also matching up at 12 o'clock and 3 o'clock positions matching the mark on the sproket from main cam once it's TDC....also adjusted air mix screw on bottom of carb to 2 turns out and 1/4 turns at a time either way and still nothing....moved both intake and exhaust cams counter clock wise 1 tooth while keeping all other TDC marks the same and actually sounds a little more promising but still NO START

The guru of all things KX is Numroe, drop him a pm and see what he has to say.

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 I think you mean the intake boot. Yeah i have looked at that and its in very good shape and clamps are tight down. I still don't get anything even with starting fluid. Does any one know what i should expect to see on the compression gauge although i know you cant really do a compression test on a 4stroke? 

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