Bike cutting out at half throttle while riding

[onebadtlbabe]

When my bike gets up to normal running temperature and I'm cruising at a normal speed and I go to roll on the throttle more than half way, it completely shuts down and almost throws me off the front of the bike. As soon as I let off the throttle it goes back to driving normal. The fuel injection light has come on one time but I was unable to get an error code because it shut off. Ive also tried riding the bike with the gas cap open- its not a venting problem.

[Six5]

Re: Bike cutting out at half throttle while riding

So, while it is running on the "cold" map it doesn't do it? It olny acts this way on the "warm" map?

Does it always happen at the same RPM?

Have you serviced the fuel filter lately?

Happens in any gear?

[onebadtlbabe]

Re: Bike cutting out at half throttle while riding

It only happens when warmed up, mostly between the 4 and 7 thousand RPM range, haven't serviced the fuel filter, and it happens in every gear.

[Six5]

Re: Bike cutting out at half throttle while riding

So, when it is "cold" it works fine. You can wind it up to any RPM and it does not stumble? Is this true? Bear with me, I'm just trying to get a clear picture. What do you consider "warmed up?" What temp does your gauge show?

When did this begin happening?

If it stumble like that at any temperature, it is very likely a fuel delivery problem. It would be worthwhile to verify your fuel pressure - when it is cold AND when it is warm.

Does your airbox still have the IACV flappers in it? Or has it been modified?

Try running it in the dealer mode so you can read any codes that may appear.

Still thinking......


Or, could it be related to the secondary injectors? Thinking out loud.....

[onebadtlbabe]

Re: Bike cutting out at half throttle while riding

It only does it after riding about 10 minutes and when it reaches 185 degrees or more. It seems to get worse the hotter it is. It has an airbox mod done to it. and it has done it intermittently for a long time but has gotten worse.

[Six5]

Re: Bike cutting out at half throttle while riding

..... It has an airbox mod done to it.

I guess I could have read your signature. Duh.

..... and it has done it intermittently for a long time but has gotten worse.

I'm still thinking it is a fuel delivery issue. Bad fuel pumps as well as clogged pickup screens as well as old fuel filters can cause intermittent problems. Also clogged injectors? When you wind open the throttle, you are asking these components to perform at their best - and they can't. But when you are cruising, the engine is happy with what meager fuel supply they can deliver.

I may be off base, but if it were mine, I would at least verify that the fuel rail is getting the pressure it needs. The manual says 41 psi. Once that is done you will know whether to pursue the fuel issue or look for possible electrical problems - like ignition coils and wires, flakey PCIII, etc.

That reminds me. Have you tried running it without the PCIII in the circuit?

[CWBethel]

Re: Bike cutting out at half throttle while riding

INJECTORS might also need cleaning but also TPS can cause similar issues good luck...

[Six5]

Re: Bike cutting out at half throttle while riding

INJECTORS might also need cleaning but also TPS can cause similar issues good luck...

Good idea. The TPS is another good place to look. You will need to test it per the service manual on pages 4-39 and 4-40. Make sure when you are watching the ohmmeter or the voltmeter as you SLOWLY turn the throttle that the readings likewise increase steadily and smoothly - no glitches or dead spots.

Might want to start with this test. It is less messy than checking the fuel pressure.

[Mikey75702]

Re: Bike cutting out at half throttle while riding

I was having a similar problem. Coming out of left handers on the track the hike would try to spit me off (i am slower in left and get ham fisted to try and get sped back up for straights) I pulled the fuel pump and put a filter in it. The filter was clogged horribly, and that was my issue. The warmer the bike got the worse it got, and happened in between 6-9 k rpm in any gear. I came to the conclusion that with the filter clogged, the bike was running lean, and detonating causing my problem. The bike dropped about 4 deg f, once fixed too.

[onebadtlbabe]

Re: Bike cutting out at half throttle while riding

turns out it was the fuel filter in the fuel pump. It was clogged from a rusty gas tank.

[Mikey75702]

Re: Bike cutting out at half throttle while riding

Glad you got it sorted

[Six5]

Re: Bike cutting out at half throttle while riding

Thanks for posting the fix.

[smonkbmw]

Re: Bike cutting out at half throttle while riding

ha, i was just reading this thinking it was the same issue i was having.