CRF450X thread.....

[zzlejeune]

I did a search for another CRF450X thread, but none showed up, so I figured I would start one......


I recently purchased a 05' CRF450X with a Baja Designs dual sport kit, with some extra aftermarket parts, but pretty much stock. I had a 02' XR400R, I miss it terribly, but it had no title, so I didn't feel like going through the hassle. But I have to admit, the power is night and day between the 2 bikes, that 450X is silly fast.

I really wanted to find out from other CRF450X owners about the certain "issues" with the bike.....

Issue #1: This is my first "new" CRF I've ever owned, so is it normal when the header looks like its going to melt, when its just sitting there warming up? That bad boy is HOT!!

Issue #2: Everytime I seem to stop for a bit, the bike will start spewing coolant from the overflow line, I do have aftermarket radiator guards on it, will that affect the cooling when just sitting still? It does seem to act pretty normal when riding.....

Thanks ahead of time for any input..........

The bike...... (Sorry, crappy phone pic)

[zzlejeune]

A pic of both the bikes, I sold the XR, regret it now......

[desertridernm]

Sounds like your X is jetted too lean. Have you checked the spark plug? I've got an 06' that never overheats and gets put through it's paces at 6000' ft. elevation up some fairly steep hills and deep sand. Try a JD Jet kit and get it dialed in. These bikes are beasts in the desert with significantly more power and better suspension than a XR-400. Don't look back!

[jgunsett]

I have an '05 with a Trick Dual Sport kit on it, plated in Ohio. The only time I've ever over-heated was in a few stuck-in-mud-in-90-degree+ temp situations. Even then, I've never blown any coolant out the overflow tube. BTW, I'm getting ready to sell my 450X. Would you mind sharing how much you paid for yours? I'm trying to figure out how much to ask for it.

[zzlejeune]

Originally Posted by desertridernm

Sounds like your X is jetted too lean. Have you checked the spark plug? I've got an 06' that never overheats and gets put through it's paces at 6000' ft. elevation up some fairly steep hills and deep sand. Try a JD Jet kit and get it dialed in. These bikes are beasts in the desert with significantly more power and better suspension than a XR-400. Don't look back!

It is backfiring some after it idles down, which takes forever, I believe the PO installed a bigger jet, but replaced it with the stock one, I do plan on getting a JD jet kit for my Colorado trip coming in August of this year. I also purchased a flex jet kit, which allows for "slow" jet adjustment, so maybe that will help also.......The suspension is awesome on that bike, it can practically climb a hill by itself.....Thanks for the advice, I'll get that JD jet kit on order.....

[zzlejeune]

Originally Posted by jgunsett

I have an '05 with a Trick Dual Sport kit on it, plated in Ohio. The only time I've ever over-heated was in a few stuck-in-mud-in-90-degree+ temp situations. Even then, I've never blown any coolant out the overflow tube. BTW, I'm getting ready to sell my 450X. Would you mind sharing how much you paid for yours? I'm trying to figure out how much to ask for it.

I paid $3900, I think KBB was $3590 when I bought it, it was clean and street legal, so I didn't bother haggling...

[jgunsett]

Originally Posted by zzlejeune

I paid $3900, I think KBB was $3590 when I bought it, it was clean and street legal, so I didn't bother haggling...

Thanks. I was going to ask $4000, which includes the Scott's Stabilizer, so it sounds like I'm in the ballpark.

[r00t4rd3d]

If thats running so lean to the point of over heating and blowing coolant out the overflow , I would not start it till the jetting was worked out. Unless of course you want to buy a new top end for your new bike.

Has your pipe been red hot ?

[zzlejeune]

Originally Posted by r00t4rd3d

If thats running so lean to the point of over heating and blowing coolant out the overflow , I would not start it till the jetting was worked out. Unless of course you want to buy a new top end for your new bike.

Has your pipe been red hot ?

Oh yeh, super red hot, like spit on it and it flies off, that kind of red hot! I talked to some guys who race the CRF450R and they did mention the header getting hot, but I doubt its this bad.....

[woods wizard]

Like they all said, Not normal, get the JD jet kit. You are going to end up blowing the head gasket, or worse. you think its fast now? wait till you get it sorted out. Also you need to run 1 full qt. of oil in the trans side , not .7 the manual says. I use engine ice coolant, helps in the slow going trails.

[Mo-Tarded]

zzlejeune: Also, you do realize you can't just start the bike and let it sit there idling like the XR correct ?

IOW: How long is "just sitting there warming up" ?

The bike will warm sufficiently in ambient conditions (50-70 deg F.) in 2-3 minutes easily. More than that is probably overkill.

After ten (10) or so minutes with no convection through the radiators (depending on outside temps) you could be close, if not in the overheating range.

"Silly fast" is a good thing. Like going "hyperspace" in Star Wars.

[zzlejeune]

Originally Posted by woods wizard

Like they all said, Not normal, get the JD jet kit. You are going to end up blowing the head gasket, or worse. you think its fast now? wait till you get it sorted out. Also you need to run 1 full qt. of oil in the trans side , not .7 the manual says. I use engine ice coolant, helps in the slow going trails.

I was worried about the top end going, so I did limit my riding in its current state of disorder. I was warned a couple of times about the "effects" of slapping the proper jetting in it.... I run Water Wetter in my track bikes, and I was wondering if it would be ok to run in the X.

Originally Posted by Mo-Tarded

zzlejeune: Also, you do realize you can't just start the bike and let it sit there idling like the XR correct ?

IOW: How long is "just sitting there warming up" ?

The bike will warm sufficiently in ambient conditions (50-70 deg F.) in 2-3 minutes easily. More than that is probably overkill.

After ten (10) or so minutes with no convection through the radiators (depending on outside temps) you could be close, if not in the overheating range.

"Silly fast" is a good thing. Like going "hyperspace" in Star Wars.

I did try to not let it sit long without getting some airflow across the radiators, I would probably say around the 8-10 min range, so I was probably pushing my luck, and even then it would die out once I turned the choke off, I had to constantly play with the idle screw.

I will settle for "hyper-space" speed, just as long as it doesn't hit "Ludicrous" speed, then my face may rip off......

[woods wizard]

If you really want the best info, not wives tales, go to CRfs only.com. everything you need to know.

[zzlejeune]

Originally Posted by woods wizard

If you really want the best info, not wives tales, go to CRfs only.com. everything you need to know.

I frequent that site pretty often, they even helped to deplete my checking account some.....

Their how-to articles are handy, and explain mods very well, I even tried to wrap my first header, just for the hell of it.......

[BikePilot]

Red hot is actually quite normal for a thin-wall header - most modern 4-strokes actually do this. It won't usually be red when you are riding due to the airflow I guess, but at a fast idle it'll glow. No worries (and definitely don't go and try to jet the bike based on header temp). If you mess with jetting just jet it so that it runs the way you want it to run. Also, you needn't worry about hurting the top end with jetting - it isn't really possible (note how most all non-MX bikes come lean from the factory, but virtually none cook themselves?). I think back way before I was born motors were poorly made and had to add extra fuel for cooling - they weren't able to run at an optimal mixture (which generally would yeild peak EGT). Technically, a lean mixture will actually reduce temp, but most folks are rich so leaning might increase EGTs, but you needn't worry. Again, just jet it so it runs well.

If you care, the first thing to go from high EGTs will be the exhaust valves. The head gasket doesn't give a crap what EGTs you like (though sitting around for 10 minutes without moving might be pushing your luck with coolant temps). It is normal for it to overheat when stopped. Unlike street bikes and cages its cooling system only works when the bike is moving (no fan). It isn't made for being stopped and running.

The CRF is a fantastic, high performance bike, have fun with it and don't worry so much (but also don't treat it like a cage and leave it idling forever!).