I too have experienced occasional fuel starvation engine cut-out after sustained periods of WOT on the highway.*

In my case, I only began experiencing the problem after I installed an in-line fuel primer bulb to assist with cold starts. Because I hadn't heard others complain of the same issue, I just assumed that the problem was being caused by the primer itself; perhaps the one-way inlet valve getting stuck or something similar. I normally resolve the problem when it appears by reaching down and giving the primer a squeeze, and the bike carries on as per usual. The problem may then reappear after another 15 min or so, but another squeeze on the primer fixes it again.

I have not previously raised the issue on this forum because I frankly believed it was self-inflicted (due to my installing the primer), but your report has now got me wondering???

I'd also suggest making sure your main jet is free of debris and installing an inline fuel filter.*

 

Thanks everybody for the tips so far.

I had installed an inline filter prior to last weekend's issue... I took it out thinking it might be related.

Interesting idea that it might be running out of fuel... BUT... if I go outside right now and fire it up, it still won't run. So I have to think then maybe there IS some sort of crap getting into the carb and plugging things up. I guess I'll have to drain the tank and check everything out tomorrow.

Oh, as for the Instructor bit... if I pass, I will get a job as an instructor here in the NW Oregon area. It doesn't pay much (they haven't even told us that part yet; but they stressed it isn't much), but it'll be fun. And it could lead to being able to do ADV Camps and stuff too.

Rob

 

I still wonder though... why is it that this rears its head ONLY when going WOT? The bike runs perfectly as long as I don't use WOT.

Rob

 

Sounds very similar to a problem I had with my klx650 back in oct/nov. Bike would work fine from idle up to almost WOT, then only up to mid, then only idle within a few hours (no issues before). Mix of water in the gas and poor quality gas plugging up the jets and coating the needle was the problem for me.

 

I may have found my problem. I cleaned out the carb, drained the gas, and then decided I'd go ahead and clean the air filter while I was at it. I removed the filter, and this is what I saw:



Why in the F is that metal screen all rusty? I got two of the three screws holding it in out, and looking behind it, there was all sorts of rust-type particles in there. Safe bet this is the crap that's been getting into the carburetor at WOT, though fwiw I've never found any evidence of it in the carb.

A new one is $28. But to even replace it I'm going to have to remove the whole airbox. And to do that it appears I have to pull the exhaust and rear shock just to get to all the damn screws. I have to split the airbox to get to that third screw. They sure didn't give any thought to serviceability when they designed that part. Fawk.

I'm so fed up with this damn bike. It's been nothing but trouble (or at least it seems that way). I can't afford to order replacement parts right now, and even if I could, they're all two weeks out.

Rob

 

Hey Rob, do you think you can clean it with some CLR or other lime-a-way product?

 

I suppose I could, once I can get the damn thing out. It's gonna take another hour of disassembling the bike to get to it, and a trip to the store for some cleaner. So far carb cleaner hasn't done crap to get it clean, that's for sure.

I remember some had talked about cutting the screen out entirely, but that doesn't seem like a good idea.

Rob

 

Hmm, that rusty screen sure can't be *helping*, but it's hard to imagine it's *causing* your motor cutting out either. Any of the minute bits of crap that might be dislodging from it should be small enough to sail right through the throttle body rather than getting stuck in a jet. Air dynamics is a pretty sophisticated science however so it can't hurt to test ride with a cleaned up screen, at least to eliminate it as a cause...
I wonder if the rust is actually a symptom of some other problem which is also causing the motor to cut out?

 

Water-logged foam air filter?

Don't give up yet! How p****d would you be if you sold then a while later you see it ripping around and the new owner tells you "Oh yeah, it was just xxxxx. Sweet machine, I'm lovin' it."

You will get it sorted out. Hang in there!

 

Yeah that looks really bad. Very curious how that happened. I'm sure it wasnt that way the last time you cleaned the air filter. How long has it been , and where has the bike been since then. Crazy.
The screen can be cut out. Many have done it for "more power" . I cut mine out but didn't notice a difference in power. I would cut yours out, or get a new one, I wouldn't mess around trying to save that one. No solvent such as carb cleaner , acetone, etc, will remove rust. CLR contains a type of acid that will eat the rust, but I wouldn't go spraying that in there, as it will also work on other metals ( carb etc. ). Search on here for backfire screen removal. The air box is the toughest part of the bike I have ever had to remove. I forget exactly how I did it.
Good luck Dan