05 Crf 450 issue (please help)

[Easternrider87]

So, before I begin, forgive my ignorance, as I am somewhat new to the sport. I found an 05 450R on Craigslist for 800 dollars and decided that It would be a nice project to start with my old man.

The bike is totally solid with no leaks and good compression, but did not start. ( but for 800 bucks, I couldn't resist.).

After cleaning the carb from head to toe, it still would not kick start, however, roll starting works fine and the motor is very powerful and sounds great....but when I stop, it won't idle and the choke will not stay pulled out. (Keeps popping back in on its own.).

When I try to kick start, I get the occasional pop, but no bang... Any tips for adjusting the mixture or do you think the valves need to be re-shimmed?

Thanks guys! -Matthew

[Easternrider87]

Update: I have been successful at kickstarting the motor, but I have to give it half throttle and if I let the rpms get below around 1800, it will die, (no idle)...I have backed the fuel screw out but still no bueno.

[Eddie8v]

Sounds like a clogged pilot jet or somehow the pilot circuit is plugged up.

[Easternrider87]

Does the pilot jet need to be backed out a few half turns like the fuel/air screw?

Edited March 31, 2013 by Easternrider87

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https://www.thumpertalk.com/topic/271735-how-to-confirm-your-pilot-circuit-setting/

[Eddie8v]

Yes, if you have it screwed all the way in that could be your problem, you should back it out the "standard" amount listed in your Owner's Manual and start from there. It is a fuel screw, not an air screw like in a 2-stroke, so turning it out, counter-clockwise, adds fuel = richer, opposite of a 2-stroke which adds air = leaner.

[dtha70]

Sounds like the pilot and AP circuits are in need of adjustment, and it was probably 800 bucks because it needs valves

[Easternrider87]

Well, I have turned the fuel screw out to 1 and 1/2 (didn't help) and then out to 2 1/2 then past 3. I still have to be on the gas to start it. So I'm guessing I need a new (larger) pilot jet. But what do you guys think in terms of size? I read that the factory set jetting is 42, so maybe get a 45?

[susco64]

Well, I have turned the fuel screw out to 1 and 1/2 (didn't help) and then out to 2 1/2 then past 3. I still have to be on the gas to start it. So I'm guessing I need a new (larger) pilot jet. But what do you guys think in terms of size? I read that the factory set jetting is 42, so maybe get a 45?

Don't assume it has stock jets. Verify. And make sure pilot is not clogged. If the choke is not staying out on it's own there is a problem with it, unscrew it from carb and clean, inspect it.

[erichshonda]

Make sure your hot start system is working properly. Lever should have play in it, and should snap open when released. If stuck open, this causes a lean condition .

[Easternrider87]

Guys, I really appreciate your help, I will give the hot start more play (as it is pretty tight and does not snap back), inspect the choke and pilot jet internals. I will be back with an update this evening. I'm guessing the jet size will be inscribed on the jet itself?

[dtha70]

Yes the jets will have numbers on them