Engine bog

[knovello]

I've got a bizarre problem with my 2012 ec300 Race that I have not been able to figure out. My engine boggs out(sounds like I hit the kill button) when I land from a big jump or on impact hitting large whoops.
Anyone have any ideas??

[andoman]

I'm watching this closely.
I had the exact same problem on a big-bore Orange Thumper. Never could sort it and ended up replacing the carb! I had been wanting a 2mm larger carb anyway, so it was a good excuse to go shopping. But, still, the symptoms were bizarre and no one had a clue where to start.

Sorry I'm no help, but Good luck!

[knovello]

Yeah, what's weird is that it just started doing this the other day for no reason. No crashes and I hadn't been working on anything. It just started doing this 30 minutes into my last race.....

[Diggs345]

Check the easy things first , like a loose wire or faulty kill switch , or maybee a bit of grit or water got into your carb

[Jakobi]

Originally Posted by andoman

I'm watching this closely.
I had the exact same problem on a big-bore Orange Thumper. Never could sort it and ended up replacing the carb! I had been wanting a 2mm larger carb anyway, so it was a good excuse to go shopping. But, still, the symptoms were bizarre and no one had a clue where to start.

Sorry I'm no help, but Good luck!

Did the new carb fix it??

Originally Posted by Diggs345

Check the easy things first , like a loose wire or faulty kill switch , or maybee a bit of grit or water got into your carb

Agree. Check the wires around the head steam and forks, and all around the rear shock as well. May be a wire thats rubbed/pinches when the boingers compress. I'd at minimum drop the fuel from the carb bowl to inspect for contamination, but more likely I'd pull the whole carb for a clean and check the floats etc while in there. If you flip the rear subframe to get the carb out it'll give you a good chance to check things out around the shock too.

[andoman]

Originally Posted by Jakobi

Did the new carb fix it??



Agree. Check the wires around the head steam and forks, and all around the rear shock as well. May be a wire thats rubbed/pinches when the boingers compress. I'd at minimum drop the fuel from the carb bowl to inspect for contamination, but more likely I'd pull the whole carb for a clean and check the floats etc while in there. If you flip the rear subframe to get the carb out it'll give you a good chance to check things out around the shock too.

New carb solved my problem.
Good advice checking for a short when the suspension compresses.

With regards to a starting point for troubleshooting, logic tells me this:
If its a kill switch or ignition wire grounding, it will have a uniform bog with throttle position having little or no effect. If your problem is in the carb, then throttle position and load will make the bog change characteristics.

[wence]

I had a similar thing happen to my 12 when I cable tied the fuel tank vent hose to the newly installed steering damper.The bike would bog and stall after I had been revving high for a bit due to the restriction on the fuel vent tube.
I wondered whether it could be a similar thing as you would be revving in the whoops and could also be revving when jumping?
Clutching at straws , but may be worth a look?
Cheers Mark

[Jakobi]

Definitely check breather lines on both the carb and the fuel tank. Great advice by Ando regarding trying to isolate an action to the cause.

[knovello]

Good stuff, thanks guys! I'll let you know what I find out.