Wr450f stalled and won't start

T

timelinex

2014 wr450f

I went riding with (in 105 degree weather) with my son (pw50) and made the mistake of taking the 450. I was riding for a good 45 minutes or so at 10-15 mph (lol). It was definitely heating up (I could hear the radiator fluid), but it was running fine. Climbing up hill I went a little too slow in 2nd gear and stalled. (No fall). I spent the next 30 minutes trying to unsuccessfully start the bike. Everything seemed to work correctly, and the engine turns over (and you can hear the fuel pump), but it just doesn't start. I ended up having to walk it back to the truck.

Here is everything I've tried:

1. It's been tried warm and cold (right after stalling and now cold)

2. Both electric and kick start

3. I pulled and shorted the clutch wire coming from the lever to make sure it's not that.

4. Unplugged the kill switch to make sure it's not that

5. Pulled the spark plug. It looked mostly fine and it sparked to the engine when tested. I replaced it regardless.

6. I pulled the hose from the tank and fuel pump. It was flowing and when the bike is started or when I'm pressing the start button the weak flow turns to a powerful push. So puel pump seems to be building pressure correctly.

7. I didn't pull the injector , but I tried listening to it firing and I'm pretty positive I hear clicking. So it seems to be working. I can't guarantee it's not clogged since I didn't pull it....but bike was working just fine right up to the user error stall. So even if slightly clogged I don't see how it would start at all.

8. Pulled the 2 15a fuses to reset computer.

I'm stumped. As I mentioned, it's turning over as if it's about to start but not starting at all.

What else could it be?

Thanks guys
 
T

timelinex

Ok guys, I tried starting fluid and it starts for a second and dies. I could get it going for longer as long as I kept adding starting fluid but it wouldn't ever actually catch on and run on its own.

So then that means fuel isn't coming in right? Since I've confirmed that fuel pump works and that hose isn't kinked, does that mean injector is bad? Or could be valves? Or what?
 
2strokesteve89

2strokesteve89

I would definitely check the valve clearance just to get that out of the way, also I didn’t see you mention if you checked for air leaks……as it may have gotten pretty hot, have you checked compression? also maybe try to clean the fuel injector, I know they have kits out there for this. Hope you get back out there with the kid.
 
T

timelinex

Thanks for the advice guys. I decided to take it to my dirt bike mechanic. I did all the "Easier" checks and for the first time didn't want to waste several hours going down rabbit holes.

I mentioned checking valve clearances to him as it hasn't been done in a long time. He says usually that is only an issue when people don't change their filters and do oil changes. He then proceeded to manipulate the kickstarter and said he would bet money that there is more than enough compression and valves should be good, based on the resistance he feels. He said of course he could check them if I want him to, but it will likely be a waste of my money. This is the first time I've seen someone do this with a kick starter and say that about valves. But his incentive would be to tell me the opposite of what he did, so I have no reason to doubt his advice.

He said his money is on a fuel pump. Said that even though I did a simple check which showed pressure increased strongly on ignition, the pressure could still not be strong enough and the bikes can be very sensitive.

We will see what he says it is this week.
 
SRAD97750

SRAD97750

Moderator
Staff member
timelinex:
I mentioned checking valve clearances to him as it hasn't been done in a long time. He says usually that is only an issue when people don't change their filters and do oil changes.
Click to expand...
This is not true and I would absolutely second guess anyone that says this.
Valve Clearance is not related to those items in anyway.
-BIG DAN:thumb:
 
SRAD97750

SRAD97750

Moderator
Staff member
timelinex:
Ok guys, I tried starting fluid and it starts for a second and dies. I could get it going for longer as long as I kept adding starting fluid but it wouldn't ever actually catch on and run on its own.

So then that means fuel isn't coming in right? Since I've confirmed that fuel pump works and that hose isn't kinked, does that mean injector is bad? Or could be valves? Or what?
Click to expand...
If it runs on starting fluid, then you're not getting fuel.
Injector or Pump is my bet. -BIG DAN:thumb:
 
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