brand new 09 yz450f wont run!!

okay guys bear with me i'm not a good writer.lol So i picked up my 09 yesterday it woudnt start.it took forever for the dealer to get it going, they suck!i rejetted it 48p 165m 1 1/2 turns on the fuel screw.it will start with the choke out and the hot start pulled in.once it starts it idles fine.it just super hard to start,im sure its the tight engine ant jetting.please help.I have an FMF mega bomb and a Q4 silencer.ill be riding in temps from 20-45 degs for the next month or so.

Thanks,jon

also check to see it the hot start is stuck open.. I have seen new YZ's delivered dry and they will stick, which make it very hard to start!

its cold and new! That's normal

its cold and new! That's normal

I agree. Went through the same thing with mine. After a few heat cycles, it starts 1st or 2nd kick, hot or cold.:moon: I am running the same jetting except I am 2 out on the fuel screw.

I would make sure you prime it, twist the throttle about 4 times usually does it for me.

Choke richens it, hot start leans it. Why would you use both at the same time?

And I second the priming part. My KTM, I would never touch the throttle. My '09 YZ I did the same and it always took a number of kicks to start. Once I started twisting a couple times first, it fires on one or two kicks cold.

thanks guys.i got three heat cycles on it now.Its lighting up way better.

Choke richens it, hot start leans it. Why would you use both at the same time?

i had it choked after about 30 kicks i pulled in the hot start and it fired up.lol

hard to start here also.

did urs ever feel like it "didn't" have compression? i bought a new 2009 YZ450F(off the showroom flr / zero hrs) last wednesday and at times while trying to start it, it felt like a valve was still opened...

not at all man the compression is alway the same so far.

I had the same problem,id check your sparkplug,if its not golden brown your too rich on the pilot jet.I run a ti ti dr.d pipe and header,pro flo twin air filter and stick with 45p-165m and switched the needle to nfpr which is half a clip richer than stock-1 1/2 on the fuel screw.I added the r&d power bowl as well.She fires on 2 kicks every time.All weather conditions -10 deg to+20 deg.

Edited by ectm3
add more info
I had the same problem,id check your sparkplug,if its not golden brown your too rich on the pilot jet.
How would he be able to read the plug color? The bike is brand new.

I always refrained from touching the throttle on all my past fourstrokes, but this bike(08 450) really responds to two blips of throttle before kicking cold.

2 blips, choke set, kick from TDC, done.

I always refrained from touching the throttle on all my past fourstrokes, but this bike(08 450) really responds to two blips of throttle before kicking cold.

2 blips, choke set, kick from TDC, done.

This is the routine that my 09 seems to like as well.:banghead:

i installed a RideEngineering fuel screw it the carb the other day, 2-1/4 turns out. turn on the fuel, pull the choke out, 2 blips of the throttle, and kick twice and it starts.

i had put some run time on the bike while on the stand. it seems to have done it some good.

the issue with "low compression/valve opened", i beleive it to have been, going through it's cycles trying to find TDC

How would he be able to read the plug color? The bike is brand new.

Dont people make sure the bike runs befor they purchase it?I wouldnt buy a bike unless i take it for a boot around the parking lot,and let it idle.If it doesnt run-dont buy it! I assume too much.The plug color is just a guid line.

Dont people make sure the bike runs befor they purchase it?

Apparently not everyone. But then, a lot of people don't read the whole thread before posting, either :banghead: See the first post, it explains things.

its good now guys!i did a few heat cycles now it fires right up.and yes it was running fine at the dealer.i think im going to love this bike,after five years on ktms im stoked to get going on this yzf.

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