Frustrated - 2008 450 SXF Starting Problem help please

I have an 08 SXF 450 with about 95 hours total and 35 hours on new top end.  I have been trying to figure out why my bike seems so hard to get started & some input would be greatly appreciated. I have read quite a few threads and im still trouble shooting it. It seems like it doesnt crank over quite quick enough to pop it off. I have tried a new yuasa battery and a new Shorai lithium battery & have got it to start off of them here and there when they are newer. But seems like when the motor is warm or hot its harder to pop off. When I jump start it with another battery off a car it pops right off. The first thing i checked was spark and it was really weak and intermittent. I cleaned ALL electrical connections & used die electrical grease and made a new ground and have a iridium plug in it and that helped a bit & was night and day on spark because they have a bad ground setup factory. I also made sure the timing was perfect. I went through the carb & put a jd jet kit in it. 


The only other thing i can think of is the auto decompression on the exhaust cam. Can it slowly stop working & make it harder & harder to turn the motor over the more hours you have on it? Or is it more abrupt than that when it quits working? If its the decompression what is the part# for the new updated cam?


Thanks in advance for all the help. I really appreciate it.



No one has any ideas? Anyone know about the auto decompression?

So its the 2010 exhaust cam. Anyone know if it slowly gets harder to start or is it more abrupt?

I had a 2011 do the same thing. Pop off the valve cover and check the exhaust cam auto decompression and finger follower to the valve. If there is any wear on any of the parts it will not allow the valve to open far enough during starting and make it hard to start. All parts should be black from the dlc coating not a raw aluminum color. Also look for if the auto decompression pin is bent. Good luck. I had to replace exh cam and finger follower then all good again

Awesome thanks for the input. I have already looked over the finger and it was black and still had the coating but is the little part of the decompression lever that pushes on the finger follower supposed to have a coating as well?

I will look to see if its bent, didnt check for that.

Thanks again for the help.

Yes the part that hits the follower needs to be coated. If not it has probably worn down. After it gets past the coating it doesn't take long

Yes the part that hits the follower needs to be coated. If not it has probably worn down. After it gets past the coating it doesn't take long

The brushes in the starter motor may need to be changed.


I had 75hrs on my bike and they were worn pretty bad..


You can find the right kit for your bike on ebay

If the brushes are worn would it cause it to crank hard? also why would it pop off a lot better when its jump started?

U have a better explanation?

How hard is it to yank the starter off and check the brushes?

Just be careful when assembling it.

Everythin is functioning, just need a fresh batt every time to start it up.

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