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The dreaded no start..04 crf450r

Posted: Wed Mar 22, 2017 5:37 pm
by 450%FASTER
I'm trying to tshoot a no start condition after reshimming valves and replacing a cam chain. On last ride of last season, was running strong but was backfiring a little bit on decelerationand had little trouble idling at the end of the day, and I had noticed cam chain noise from when I purchased it. So I figured it was about due for a cam chain, tensioner and another valve adjustment since I replaced them with SS KW's in June. Im positive the timing is correct and I'm getting gas(wet plug, acc pump delivers stream past slide) and spark when grounded to frame, (blueish and consistent), and have air filter removed. Added gas directly to cylinder, Won't even cough. Not sure when the last piston change was but I do have good compression based on feel when covering plug hole and sealing drain hole.(compression tester is shot, got one on order,along with a PVA). So I'm thinking stator, coil...? I believe I'm testing ohms correctly across blue and white. I'm getting 20-21 ohms on blue and white at 4 prong harness behind number plate, but 2-6 ohms at blue and white wire connections near carb. Also, I removed and cleaned carb just to be sure, but it was perfectly clean. I did see 2 tiny pieces of metal near oil pickup on left side when replacing the cam chain, and thin film of metallic residue on bottom of case, and the magneto. ... Worried the crank may be going.. Anyone have specs and procedures for ignition system TS? Have a Haynes manual but it's not all inclusive

Re: The dreaded no start..04 crf450r

Posted: Sat Mar 25, 2017 8:28 am
by crfsonly
Have you resolved this issue? Any updates on where you are at this point in troubleshooting?

Ken

Re: The dreaded no start..04 crf450r

Posted: Tue Mar 28, 2017 11:55 pm
by 450%FASTER
I have lost spark during troubleshooting.. possibly due to a component failure from spark plug not being firmly grounded while kicking over and checking compression (which came in @50psi btw with decompressor still in place) Resistance checks are all over the place. Will be 6ohm at blue and white on stator leads, then minutes later 1or 2 ohm(and just now 20ohm). Other 2 leads come in at 9 or 10 ohm (and 30 just now @ 52°)so I've ordered a stator. Also the coil tests all over the place between POS and neg. 5-25ohm (140-160 now) and only reading at the 20k setting between POS and plug cap just now... so I ordered that too. Checked the wiring and no cuts or scrapes to the tape covering it although I haven't taken all the tape off from connections near carb to coil, and on to CDI. The kill switch was disconnected early in the process. Not sure if the pulse generator, exciter coil in the left side is adjustable? I changed the timing chain and removed stator and components and when I put them back in I just tightened everything down with the wiring held down with the retainer but didn't know if it was supposed to be adjusted for proper operation.

Re: The dreaded no start..04 crf450r

Posted: Wed Mar 29, 2017 8:25 am
by crfsonly
Sounds like you have some parts coming that make sense. I would recommend you remove the kill switch at the harness connection. I've seen that point cause no spark issues before. Check back in once you have the new parts installed. Good luck.

Re: The dreaded no start..04 crf450r

Posted: Fri Mar 31, 2017 4:46 pm
by 450%FASTER
Got the new coil today. Does the cap just pull off the old coil wire and push on the new one? I read somewhere there is a spring and resistor in there.. The end of the new coil wire has a tiny(1/4mm) hole.. do I strip the end or is there a tiny rod that links up with it?

Re: The dreaded no start..04 crf450r

Posted: Fri Mar 31, 2017 8:06 pm
by JimDirt
can you post a picture of the coil ??
You need a hosting site like Photobucket or something , then just link the picture here and it will show up as a picture

It will look like this

[ IMG]http://i825.photobucket.com/albums/zz17 ... CF5152.jpg[/IMG]

But it will show up (in the Preview and in your post) like this
Image

Re: The dreaded no start..04 crf450r

Posted: Sat Apr 01, 2017 11:41 am
by 450%FASTER
Image

Re: The dreaded no start..04 crf450r

Posted: Sat Apr 01, 2017 11:45 am
by 450%FASTER

Re: The dreaded no start..04 crf450r

Posted: Sun Apr 02, 2017 7:02 am
by JimDirt
Image

In Photobucket , use the link "IMG" near the bottom of the list on the right and it will post the image directly as i have done

As far as the cap goes , you should be able to unscrew the plug cap (counter clockwise) and then screw it on the new coil , just use some WD-40 or Carb Spray into the boot sleeve on the wire side if its sticking and wont twist off , and it should unscrew easily , then screw it back on (clockwise) to install it .... The resistor is in between the part that screws on and the part that attaches to the plug , so no worries damaging that