CRF 450 Sputtering at full throttle....HELP

[strykmaster]

Hi Everybody,
I just got back from riding for the day at Ocotillo. It was the first time I really got on the throttle on my 03 CRF 450 since break in. The bike pulled strong to 3/4 throttle and then at full throttle it started to sputter and cut out. It was acting like it wanted more fuel and wasn't getting it. Someone I was riding with said his KTM thumper did the same thing and it was a fouled plug. I kinda hate problems like this because it can be so many things. I'm hoping you folks can steer me in the right direction. Feel free to ask me any questions. Thanks for all your help in advance. Strykmaster Out

[Honda_Rider_XR]

Sounds like your main jet.. Either too rich or too lean, did you go up in elevation, per say more than 2000ft?

[Kirtwell]

I actually heard of the same problem from another CRF rider. He finally took the bowl off his carb and found his main jet laying in the bowl....can't hurt to check it...

[strykmaster]

Ocotillo is only 163ft above sea level. I think my bike was jetted for sea level. I'm not sure. I bought it in San Diego. Strykmaster Out

[Woody_393]

Were you pinned and hitting the rev limiter? Mine does the same thing when I hit it. Cuts out big time, but it's supposed to. Helps you not blow your motor. An auto Red Line if you will.

[strykmaster]

SOOOOO Thats it!!!!!!! DAMN, I thought the bike would rev to the moon. I had the bike very pinned. But I couldn't get it to cut out in 5th gear Thanks Woody!!!! Strykmaster Out

[Woody_393]

Right on... Glad to help.

[zoohoot393]

Glad it was that simple.

[Imahoot393]

So how did you like Ocotillo?

[strykmaster]

It was great My arms are spaghetti and my rear end is sore Boy, that 450 sure pulls hard !!!!! One of my buddies broke his collar bone It was crowded, but there is plenty of space to go around out there. Now it's time to clean the bike. You guys have any bike cleaning tips? Right now, I use minimal water and spray on degreaser. Should I cover the brake rotors and can I use a brake cleaner on them to remove dirt? Thanks for any advise in advance. Strykmaster Out

[TexTwister 393]

Just dont use a power sprayer near the neck and the swingarm and linkage, other than that spray her down with some simple green let it soak a few , then blast her clean. Yes u can use brake clean to clean the rotors...Then before your next ride spray the bike down with WD40 and ride all day then when you get home just spray her off and walla, the dirt just melts off...

[MILAN]

Rev Limiter?

[FFRacing11x]

YEP! Just over 11,000rpm

[bluealltheway33]

yea i kinda like my rev limiter, otherwise i'd probably have gone though many motors! its my bike saying "stop"! lol but i was always wondering how they work, does anybody know?

[smithers]

IMO, I dont think its a real good idea to ride the Rev Limiter like that. Like with other skimpy things to keep weight down, the valves and valve springs in the CRF are not as tough as say in an XR. Riding the rev limiter is just beyond the point where you are floating valves which is kinda not good. I see a lot of people complaining about have to redo their valves and I think this contributes to it. Just FYI.

[smithers]

how they work, does anybody know?

They are essentially a black box that monitors rpm's and at a pre-set rpm it starts cutting the ignition creating a miss or even a partial ignition shut down until you go back under the rpm limit.

[Woody_393]

Originally posted by smithers
IMO, I dont think its a real good idea to ride the Rev Limiter like that. Like with other skimpy things to keep weight down, the valves and valve springs in the CRF are not as tough as say in an XR. Riding the rev limiter is just beyond the point where you are floating valves which is kinda not good. I see a lot of people complaining about have to redo their valves and I think this contributes to it. Just FYI.

Couldn't have said it better myself.

[strykmaster]

I am surprised that the salesman (an avid 4 stroke rider) at the Honda dealer never told me that the bike would cut out at high rpm due to a rev limiter. It seems to me that would be some pretty critical information: I agree with smithers completely. You can rest assure, thanks to all of you, that I won't be looking to hit that rev limiter much at all in the future. Besides, this bike loves to be short shifted anyways

[Yardpro393]

all bike have rev limiters, he probably thought you knew.

[strykmaster]

Do modern 2 strokes have rev limiters too? I haven't been on a dirt bike since 1980 and my 76 Honda CR125 definately did not have a rev limiter. Maybe that's why I blew the top end a few times I can't believe I've been away from dirt bikes for 23 years.
It sure is nice to be back on another bad *** Honda Strykmaster Out