09 G450X Sudden Acceleration issue

[Mikey108]

Hi All

Just wondering if anyone out there has experienced this issue of having their BMW G450X suddenly rapidly accelerate with no input from the throttle or response to throttle input. Seems to not be a mechanical issue, but something electronic. Throttle can be completely closed but will hit the rev limiter. Has happened 3 times and is very scary. Any info would be greatly appreciated as the local dealer in Richmond does not seem to want to explore the issue, or basically really help me at all.

Thank you
Mike

 

[cactusreid]

Stop in and tell the boss-that your going to go "toyota" on him,if they don't fix your bike. They got a 3 yr warranty don't they?

 

[franhoser]

Sounds scary, have you called BMW directly?

 

[old trials guy]

Hi All

Just wondering if anyone out there has experienced this issue of having their BMW G450X suddenly rapidly accelerate with no input from the throttle or response to throttle input. Seems to not be a mechanical issue, but something electronic. Throttle can be completely closed but will hit the rev limiter. Has happened 3 times and is very scary. Any info would be greatly appreciated as the local dealer in Richmond does not seem to want to explore the issue, or basically really help me at all.

Thank you
Mike

If electronic I suspect a faulty throttle position sensor. It sounds intermittent and hard to diagnose on the computer but they should hook it up for you and have a look. Abnormal readings are often stored in the MCU (on board computer) and something may show up there. Considering the safety implications they should be all over that otherwise they expose themselves to the risks of beeing deemed negligent if something bad were to happen (heaven forbid).

It is a pretty simple job to replace the sensor.

otg

 

[farmerger]

Correct me if I'm wrong, but on my BMW GS, the throttle controls the amount of air passing through the throttle body, directly via a bowden cable and the G450X looks like the same set up. So if no one is holding the throttle open and its not stuck open, then there should no air getting in, and without air its not going to increase engine rpm no matter how much fuel the electronic controlled FI pumps in. If the throttle was sticking open cause of damage or dirt, that's another matter!

 

[old trials guy]

Correct me if I'm wrong, but on my BMW GS, the throttle controls the amount of air passing through the throttle body, directly via a bowden cable and the G450X looks like the same set up. So if no one is holding the throttle open and its not stuck open, then there should no air getting in, and without air its not going to increase engine rpm no matter how much fuel the electronic controlled FI pumps in. If the throttle was sticking open cause of damage or dirt, that's another matter!

Sounds logical and kills my theory about throttle position sensor as it has a mechanical throttle to the best of my knowledge. I would be checking out all of the throttle linkage from cable to injector including the throttle return spring. Also make sure the air bleed screw hasn't backed out or disappeared and of course check the attachment of the throttle butterfly to the shaft.

Can't think of anything else at the moment. Good input farmerger.

otg

 

[motorambler]

...the local dealer in Richmond does not seem to want to explore the issue, or basically really help me at all....

Chalk that up to a lesson learned.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx -comment deleted-

 

[g450x]

I have the same bike and have had no problems with it . I suggest that you tell bmw directly about the issue . if they cannot fix it at pacific yamaha there is a bmw factory mechanic at duncan motorsports who is said to be the best around. stir the s---- . Its a bmw.with warrenty.
Cheers Rick

 

[tomcycle]

Chalk that up to a lesson learned.

Sponsor or no sponsor, Pacific Yamaha licks donkey balls.

There,




I said it.

Dont you just hate people that speak out of turn without the facts? (motorambler)

Im not responding because the dealer is a sponsor, but because I see these out of line replys like the one above. So lets not make this a thread about how bad the dealer is but about this customers problem.

I spoke not only to the dealer but the mechanic, so I got the story from half the source.

This customer comes in complains that the bike has run away throtle until the bike hit the rev limiter, happens three times. Customer does not know why or what happened to cause the problem. Customer cant give the mechanic any clues on what he was doing before the bike had the sudden acceleration. In short there is no way that the mechanic can recreate the problem.

Mechanic checks the bike out, bike has some after market changes. Hand guards (requried modification to throttle control) Bar Risers (added a little extra stress on the throttle cable but does not appear to be the problem) Lowered trail gearing and the customer runs the bike on the hi power setting.

Mechanic makes sure the throttle assembley and cable are operating freely and not jambing on anything, checks the computer for anything thats not normal, quick test ride and all seems to be operating properly

Customer sez, not good enough the problems scares him.

Mechanic takes bike out on the weekend on his time and test the bike thoroughly, but cant recreate the problem. In fact the bike runs great.

Customer sez still not good enough, requests the dealer to change a bunch of stuff on the engine, injection system computer and who know what else, too much to list

Mechanic contacts BMW, they want to know what the problem is before they start changing everything. They want the problem duplicated.

Mechanic offers to change the throttle cables at his cost. That the only thing that he feel that could cause the problem.

Customer sez not good enough and you should have taken the bike out longer

Mechanic takes bike out again on another test ride (a real test ride) still no problem

Dealer offers to give customer the demo model to ride, which is outfitted identical to his bike.

Customer sez no not good enough

So the bike sits at the dealer and the customer brings his problem here. With his first and only post to date.
............................................................

So there you have the other side of the story, there is more to it but I left the personal stuff out.

Seems to me the mechanic and dealer have done what they can do to this point, this guy needs some help, so if you have something to add or for this guy to check, post up. I am 100 percent sure if the mechanic missed something he would like to hear about it. By the way thank you OTG and famerger for contributing

Tom

 

[cactusreid]

so how come the guy with the problem didn't tell us this side of the story?? mikey?? that's not cool !!

 

[Mad Max]

Three sides to EVERY story. Who woulda thunk it???

Max

 

[franhoser]

Chalk that up to a lesson learned.

Sponsor or no sponsor, Pacific Yamaha licks donkey balls.

There,




I said it.

Oh 6fiddy. You really hate the above mentioned. That's twice now.

 

[g450x]

That is a little more information than was originaly posted. I have had great warrenty from bmw to say the least. A new rear drive train 3 months after warrenty. My g450x has bar risers as well as a 14 tooth /51 rear and have had no reving. My response was valid as it sounded as if the dealed did not help the customer. It Is nice to get the real story . Cheers Rick

 

[Mikey108]

I will try that! Yes they have a 3 year warranty but will not help me unless they can replicate the problem themselves, so basically they dont believe me. It has happened to me 3 times, with the last time resulting in a bad crash, but when there tech has ridden it, it was fine of course. Have been riding for 20 years and never experience something like this before.

 

[Mikey108]

Thank you for your response. This is what i suspect as well, yet the wont entertain anything other than stating it has not been able to be replicated so they are unwilling to replace any parts. This completely undermines my confindence in the bike as the 3rd time this happened i was injured because of it. Not sure why they take such a stance with a bike that is supposed to have such a great warranty. They have explained to me what i am experiencing is impossible but that obviously does little to comfort me when i know exactly what happened and had to pay the consequences. It went from half throttle to full very suddenly with no imput or reaction to input from the throttle.

 

[Mikey108]

Thanks Rick, yah i cant seem to make any progress with Pac Yam, the techs seem to want to help, but any solution i present seems to get blocked by the "upper management" I have talked with BMW directly and unforetunetly they want it to be replicated and it just happens so sporatically or at the worst times of coarse. I have it happening on my Go Pro camera, but they are not interested in that for some reason.

 

[tomcycle]

Mikey108

Im not sure what you do for a living but it must be a nice job with no grey areas. Everyone here on this site will tell you troubleshooting an intermittent problem is the worst. I dont think they dont believe you, its just if they want to get paid by BMW for warranty work then they have to explain whats broken. So far the time and effort that the dealer has spent on your bike is on the dealers dime. (Its starting to read like I have interest in the dealer, which I can assure you I dont, other than I spend money there from time to time.)

The mechanic took your bike out for the entire day on the noob run and experianced no problems. What more can you ask from him at this point.

My best guess for you problem will be the throttle cables are to tight from the bar risers

or the throttle tube has something wrong with it when the bush guards where installed.

For now it looks like your on the trial and error program, make sure the dealer gets you a good deal on armour,..... just in case it

There a lot of smart guys out there, any suggestions on what the problem might be and how to prove it???

Tom

 

[flyn]

I work for a car dealership. Their warranty policies are , remove any aftermarket items that can have an effect on customers concerns and road test, Check for technical bullitins if any apply. If concern cannot be duplicate no repairs are to be performed,
Not word for word but you get the idea
I suggest you remove the bar risers and replace the throttle tube. Never hurt to have a spare tube around if thats not it .

Flyn

 

[old trials guy]

Correct me if I'm wrong, but on my BMW GS, the throttle controls the amount of air passing through the throttle body, directly via a bowden cable and the G450X looks like the same set up. So if no one is holding the throttle open and its not stuck open, then there should no air getting in, and without air its not going to increase engine rpm no matter how much fuel the electronic controlled FI pumps in. If the throttle was sticking open cause of damage or dirt, that's another matter!

I had a little deeper look into this and discovered the 450 uses a "dual throttle valve" system but I couldn't determine who is the manufacturer. My best guess is that comes from Keihin who also supplies Suzuki and KTM with dual throttle valve fuel injectors. On the Keihin systems the secondary fuel valve is controlled by the on board computer and is a "throttle by wire" device with its own servo. If you look at one of the Keihin units you can see the mechanical throttle cable spool with position sensor on one side of the injector and on the other side is a similar looking housing with a throttle sensor but no cable, only wires.

This is only guesswork but could it be the computer controlled throttle valve has something to do with this? Does anybody have more insight or information before I make a fool of myself again?

otg

 

[tomcycle]

It seems the "Toyota Syndrome" of this bike was never replicated, that includes the day long ride the mechanic at Pacific BMW did on the bike at the Nubie. The mechanic had a great day riding but did this on his own dime or should I say Pacific's dime.

Mikey108 only made four posts on this site and that was to complain about how the dealer did not support him. I know a lot more to this story but I think its only fair to post that Pacific BMW came to the table with the best of intentions. I know it sounds like Im here protecting one of our sponsors but we never hear how things end.

The probem never happended again, the bike now has a new owner and Mikey108 is riding a KTM

Tom