CRF450R very hard to start

[1sandiegan]

Hey guys, I have a 2002 CRF450R that is giving me a heck of a time trying to start it. Heres the history:

I bought this bike a year ago from a person who works for Transworld magazine who kept it in great shape. Prior to my purchase of this bike the guy did a complete head job and installed the best parts. The work was done at a very reputable shop in SoCal. The motor is completly stock with suspension upgrades, storm link, motor gaurds and various other upgrades, but none to the motor.

I have been riding it for about 6 months and it has run perfect. I'm not hard on the bike as this is my first 450 and tend to ride it to about 75% of its capability. I clean the air filter regularly and change the oil after every 2 rides. Also, this bike would start on the first kick 80% of the time and on the second or third kick about 20% of the time and has always ran perfect.

After my last ride in the Glamis dunes (where is ran flawlessly agian) I parked it in my garage. The next weekend we were going to Ocotillo Wells and I tried to start it at home just to make sure it was ready to ride (not that I ever had a problem before). It took me about 15+ kicks to start it (choke on, about 60 degress outside) and then it ran fine. I went to ride it down the street and it stalled out when idling with th choke off. I tried to kick it over agian and it would not start, also (this may be only my imagination) but it seems like the motor is easier to kick over but still not starting.

Since then I have cleaned the air filter, changed the spark plug, verified that the hot start was not getting stuck and still have no luck. Tonight I was able to kick it over avter about 15+ (choke on) and it seemed to run fine. When I took the choke off it died after about 10 seconds. (I only let it warm up for like 30 seconds cuz it's late and I didn't want to piss off the neigbors). I gave up after that. ?

I have searched the forum for like topics and have only found tips to make sure the hot start is not sticking, or that the valves need to be adjusted, or replaced. I don't have the means here to do a compresson test and I really don't think thats it because of the recent work and since it's never had a problem before. Please help!

Sorry for all the reading I just wanted you all to know the history and hope someone will be able to help me here, I need to ride this weekend! ? Thanks for all your input!

[velocity101]

Sounds like you might have sucked in some same out at Glamis. Just one grain can clog up your jets. I would start by pulling off the float bowl and making sure no jets are clogged (use carb cleaner to spray out all the jets). If that doesn't work, then you might need to pull off the whole carb and give it a thorough cleaning.

[1sandiegan]

Thanks for the help. I just read in another thread to do the same thing. I just pulled the cap and drained the gas and found a tiny bit of dirt/sand in the bottom. I put it back in then filled the bowl with gas a gave it a little kick. When I kicked it it backfired, I have to stop now because I probably have pissed off the neighbors by now, but do you think this is a sign of recovery? I can't wait 'till tomorrow to try it:)

[2ski4fun]

More than likely the pilot jet is clogged. Pull it out and shoot some carb cleaner through it.

[CRFan1]

Sounds like your pilot jet may be clogged but I would not discount valve issues or the fact that maybe your cam chain jumped a tooth somehow.....

[skychicken]

It sounds like you have fuel system issues. But, my bike takes way longer to warm up when it is cold(below 60). I have to leave the choke on for a few minutes longer and really let it warm up or it will die. Also, I have to crack the throttle about 5 more times and kick it about 5 more times than normal when it is cold. When it is 80 degrees or hotter, I never have this problem.

[socal_sierra]

^^very true. cold weather staring with these bikes is a pain. Just crack the throttle a couple times before you kick it. And let it warm up for a few mis with the choke on.

As far as your bike not starting i would have to agree about cleaning the carb. Im almost certain one of your jets is gummed up. I would also reccomend checking your valves. How many hours on the bike since the rebuild??? Have you checked them before.? A lot can change in a year of riding.

[jcsjr]

Check your valve adjustment first. If its been a year since your engine was rebuilt your valves could easily be out of adjustment and this is an easier place to start than your carb.

[1sandiegan]

Hey guys, thanks for all the help. When I get home I'll clean out the pilot jet and then the whole carb if that doesn't work. Next step will be the valves, I just didn't want to mess with them yet cuz I've never checked them on a bike and don't want to screw something up. Won't be able to check it till tonight though, I give ya'll a update.

[1sandiegan]

Probably about 40hours on the bike this year, also I have never had to crack the throttle at all even when it's 50 degress outside, never took longer than 3 kicks too, anyways I'll let ya know what I find. Thanks!

[ImprtTunr]

Not sure if this would cause it or not, but do you have an adjustable fuel screw? If so is it still there? I guess some people have had the problem with theirs falling out. Might wanna check that its still in there. Just something quick and easy to check.

[jcsjr]

It is easier to check the valves than it is to tear the carb apart and they should be checked anyway if you haven't checked them in a year.

[sprx19]

My 04 450 started getting almost impossible to start and thought I might have some valve issues so I checked them and they were fine, but the decompression arm was somehow .030 out of spec. Adjusted that and she starts on the 1st or 2nd kick again.

[velocity101]

It is easier to check the valves than it is to tear the carb apart

Ain't that the truth!

But before pulling off the whole carb, I'd just pop off the float bowl first to spray out the jets and see if that takes care of the problem. Removing the carb off a Honda requires pulling off the sub-frame!

[rhino roof]

Check valves. You said it seemed easier to kick that along with hard to start sound like valves out. 40 hrs is along time with out checking valves.

[redrider91]

Not sure if this would cause it or not, but do you have an adjustable fuel screw? If so is it still there? I guess some people have had the problem with theirs falling out. Might wanna check that its still in there. Just something quick and easy to check.

This happened to me and my bike had the same symptoms. It would only run with the choke on, and not very well, But i may be wrong, thats just my story.

[kmpacker]

If it will only run with the choke on, then the bike is acting like its running way lean (needing less air for the right air to fuel mix). Either a clogged pilot circuit or out of adjustment decompression would have those same symptoms, I think.

[kanyonkritter]

I would guess valves. Once they are out of spec. the bike becomes very hard to start.

[Yoshi1616]

My 04 450 started getting almost impossible to start and thought I might have some valve issues so I checked them and they were fine, but the decompression arm was somehow .030 out of spec. Adjusted that and she starts on the 1st or 2nd kick again.

How do you check the decompression arm? This is new to me and could be what is causing my brothers 03 450 to not start. Where is the decompression arm located? Is it hard to adjust?