CRF's Only Forums

Hi guys,
new to this forum but heard a lot of great things. Did a lot of searching and reading here before I made a new post, pls excuse me if this has been addressed but I've had a good look and didn't find anything specific to my problems. Had a few friends help but no fixes so i'm starting to get desperate.
Bike is a 2009 CRF450X (Australian model), bought it recently from a guy who rode occasionally (mainly off road), said it ran fine and just recently developed starting problems. I can jump start the bike with a car almost every time, and push starting seems to work ok too (the few times i've tried). The E Start powers the solenoid and the starter motor, sometimes if i charge the battery to full it will start the bike, run for a bit then I turn it off and it wont start again. Most of the time though the e start will power the solenoid and starter motor but won't kick over.
I can't seem to kick start the bike either (its my first dirt bike), but other friends who own bigger dirt bikes have trouble kicking it too, only managed to do it two or three times in a few months.

Bike has new;
Starter motor (don't have the old one or another to check if mine if faulty)
Starter solenoid (tried the old and new - same result)
SSB Lithium battery
Fresh fuel (disconnected the pet cock to make sure it was flowing well which it is)

Spark works

I read that some '09's were affected by a faulty auto-decompression pin (recall), I called Honda and they ran my VIN - apparently this bike was not recalled.
The bike runs great once its on, idles and revs well.
Checked the main earth and gave it a clean, scrubbed the connections to the battery too.
Hot start lever snaps back in to place and doesn't feel stuck.
All fuses are in tact.

Jump starts fine, struggles to E start or kick.
Any advice would be truly appreciated, thanks very much!
(located NSW, Australia)

Welcome to the site !!

Have you verified that the Decompressor assembly is working ?? , If its hard to kick start as well as maybe turns over slowly with the starter , then I am guessing the Decompressor is stuck and not allowing the Exhaust Valve to slightly open to relieve some compression so the engine will give a faster turn over speed , that is what i sounds like to me by your description .... , when kicking , the bike should have some compression , but if it is really hard to get it to go over with any force , then that suggests the Decompressor is hanging or even the decomp spring is broken . you do need to give these bikes a hard forceful full kick , but it should start right up when doing so , having to push start it , seems like a valve issue , either 1 or more valves is/are too tight , or the decompressor not functioning correctly ..... that is where I would start looking ................

Thanks Jim! I'll take a look at that asap, really appreciate it your help.

Hi Mitta Norath,
Agree with Jim so get the recall work done first to eliminate it.
If the decomp isn’t working then it will be hard on either starting method, and you don’t want to snap something just because it is hard to turn over. Let us all know how you go.

Thanks very much Jim & Ray, i'll have a look at that and get back to you. Really appreciate your help!

Be cautious about kicking a 450X. The cases often break.

Got around to checking valve clearance - measured .011" on the exhaust side (both) and .004" on left intake, .005" on right.
Probably need to change shims on intake side? Would i be ok to leave the .005" and just change the .004'? Probably make sense to do both while im in there...

I checked inside the cam chain tensioner lifter bolt to make sure the spring is functioning by using a small flathead screwdriver to wind it up and let it out - snapped back no problem.
Regarding decompression - next step would be to remove the camshaft to measure the gap between the rocker and decompression arm?
Very unfamiliar with this step, done some reading but cant find any definitive information on testing the decompression.

First time inside this motor so pls excuse any rookie questions, thanks!

The stock spec of .006 and .011 has some wiggle room to make it more forgivable for everyone.
I run intakes at .0045 and exhaust at .009. Less lash gives you more lift and duration, and actually sets the valves down more gently on the seat.
Honda isn't going to recommend that because they want a sloppier, more bulletproof spec for the masses.

The stock spec of .006 and .011 has some wiggle room to make it more forgivable for everyone.
I run intakes at .0045 and exhaust at .009. Less lash gives you more lift and duration, and actually sets the valves down more gently on the seat.
Honda isn't going to recommend that because they want a sloppier, more bulletproof spec for the masses.

Thanks for the advice, thats new information. And on the crankcase, I wouldn't have thought to be too careful there.

Hey guys, still struggling to find a definitive guide on how to check the decompression, can anyone help?
Heres a photo of the engine, I don't see the parts other peoples guides are pointing me to...

Your bike has the decompressor assembly on the side instead of the extra adjuster on the rocker , so there is the spring loaded assembly on the sprocket side , in the center of the sprocket , make sure that system is functioning correctly

Your bike has the decompressor assembly on the side instead of the extra adjuster on the rocker , so there is the spring loaded assembly on the sprocket side , in the center of the sprocket , make sure that system is functioning correctly

Hey Jim/fellas, iv had a look at the decompressor assembly, but don't know what I'm looking for so heres a little video, could you tell me how it looks/where I should be focusing on?
Cheers!

The Decompressor looks to be free and functioning correctly , and it looks like the pin (shown at the beginning of the video in the center of the cam moving in/out) is also working correctly , so I don't really see anything wrong with either , so I guess next step would be to verify the carb is clean inside , ....... when it does run , does it pop at all ?? , when revving or letting off the throttle ?? if the Pilot jet is clogged it will give all sorts of issues ....though usually the issues you described tend to be valve related , but it seems to be functioning , so next in line is fuel system

Also you said "spark works" , but did not mention if you replaced the plug , or , what condition the plug was in , does it look black ?? , Tan ?? , or real white/clean ?? , this might help to determine if its a fuel issue , and what exact plug is in it ??? , it should be a NGK IFR8H11 or ND/Nippon Denso VK24PRZ11 , plug gap should be 1.0 – 1.1 mm (0.039 – 0.043 in) , also Pilot/Fuel screw initial opening 1-1/4 turns out (it should be between 1-1/4 to 2-3/4 , usually ending up around 1-3/4 - 2 turns out) , fuel screw is located bottom front of the carb underneath at the front of the bowl , you will need a really short screwdriver (flat,or possibly D shaped fuel screw tool) or you can twist the carb so you can get at it , unless it has a aftermarket screw , then it should have a handle on the end you can twist

After a lot of mucking around and checking the bike has recently started to kick over with ease! All of a sudden without any real changes. E Start still doesn't work but iv more or less given up on that now that it kicks fine.
Thanks for all your help guys, i'll leave this one for now.

Last question - I have to wire up the connecter that plugs into the back of the speedo (which is stock). The last guy pulled all the wires out from the back of the connector and I have no idea which order they go back in. I tried to refer to the manual but it has a few coloured wires in the diagram my bikes doesn't have.
Does anyone have a relatively stock bike they could take a photo of the back of their connector to show me what order the wires should be?
Dont have the money to upgrade to Trail Tech or anything atm so was either going to try and get the stock one working or use an iPhone app. Anyone had positive or negative experiences there? Not too fussed on exact accuracy just need it to work.

Thanks a lot for all the input everyone, nice to have such a wealth of knowledge to rely on when google fails.

Sorry for the late reply , I have not been on here much due to family matters ....

Look at the link in this post , one of the members from Aus , contributed this , hopefully it helps

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