[fzfrank]

The issue I've been having is that when I try to get out of the city into the countryside...

I have the same issue. I started a thread last month, but this one is more current.

I got my bike back from the BMW dealership yesterday. They told me they couldn't reproduce the issue. I guess they didn't ride it long enough because my bike has done the same thing as yours after 20 minutes every time I've ridden it. The dealership had no clue and no plan, so I didn't see the point leaving it with them.

On my ride home, I figured out that my issue seems to be triggered when the bike is in gear, and either coasting, or with very little throttle applied. As I wind the throttle back up, the bike starts to buck just like yours. If I take the bike out of gear to coast, it doesn't seem to buck when I reapply the throttle. I didn't see blue smoke yesterday, but I have in the past and my oil level definitely goes down.

I thought the issue was caused by old fuel because my bike is a 2018 and had just 200 miles on it (I bought it in May 2022). I emptied the fuel tank, changed the fuel filter, attempted to clean the injector, checked the air filter, and used some fuel injector cleaner with a fresh tank of gas. The issue seems to be getting marginally better, but that may just be in my head.

 

[ARBOLMANO]

Is it the tail pipe or air box that bugs me? I do like quiet. But it the wind noise too that drives me to cheapo foam plugs. Buy a pack. I’d be the first to admit when young alert and not too bright, I loved to slip in head phones and rock out. But that could get you real hurt and later years you say “what did you say a lot” .

 

[ARBOLMANO]

If an issue only shows after twenty minutes, that’s rough on technicians. You may have to get a scan tool and drive with it. Or try a different technician who can divest some time.
So hard to diagnose an intermittent issue.

 

[porth]

are you lugging the engine, how many rpm are you at when you coast?

 

[kentforrest]

They told me they couldn't reproduce the issue. I guess they didn't ride it long enough because my bike has done the same thing as yours after 20 minutes every time I've ridden it.

@ARBOLMANO gives good advice when he suggests riding with a scan tool that is recording live data.

"20 minutes" (time) means nothing to an engine, so the trigger here is likely related to temperature or OL/CL status of the EFI system. Scan tool could help narrow down trigger.

If you lack a scan tool (or knowledge about), perhaps discuss with your dealer that you bring the bike in hot, during symptoms. Mention to your shop the difference in symptoms between neutral and in gear. They possibly did their diagnostics in the shop, and load condition may be a trigger.

If it were my bike, I would wipe adaptive learning on the ECM as a simple first step. If that didn't help, I'd ask the dealer on the next visit to please reflash the latest update. Just to quickly cross that off the many possibilities.

 

[kentforrest]

are you lugging the engine, how many rpm are you at when you coast?

@fzfrank should rule this out first.

OP's symptoms for sure aren't lug. I'd wager a small sum it will be electronics related when they find it.

 

[ovtover]

I have the same issue. I started a thread last month, but this one is more current.

I got my bike back from the BMW dealership yesterday. They told me they couldn't reproduce the issue. I guess they didn't ride it long enough because my bike has done the same thing as yours after 20 minutes every time I've ridden it. The dealership had no clue and no plan, so I didn't see the point leaving it with them.

On my ride home, I figured out that my issue seems to be triggered when the bike is in gear, and either coasting, or with very little throttle applied. As I wind the throttle back up, the bike starts to buck just like yours. If I take the bike out of gear to coast, it doesn't seem to buck when I reapply the throttle. I didn't see blue smoke yesterday, but I have in the past and my oil level definitely goes down.

I thought the issue was caused by old fuel because my bike is a 2018 and had just 200 miles on it (I bought it in May 2022). I emptied the fuel tank, changed the fuel filter, attempted to clean the injector, checked the air filter, and used some fuel injector cleaner with a fresh tank of gas. The issue seems to be getting marginally better, but that may just be in my head.

It does sound like we're in the same boat right now. When I first noticed the issue, it was after riding 20-30 minutes on a hot day through the city, then finally cruising up a long hill at a steady 40-45mph and as I reached the top of the hill I rolled off, just giving a little gas to maintain my speed. That's when it started to sputter/buck or whatever we're calling it. I've since noticed that if I keep riding, it will still happen when giving it more gas, but it's most prevalent when it's just getting a little bit. This will also happen going downhill, so it's not that it's just struggling to get up hills. As for coasting in gear, I don't love how the bike sounds or feels when engine-breaking, so I try to avoid it.
I'm taking mine back to the shop in two weeks for them to take another look.

 

[kentforrest]

I don't love how the bike sounds or feels when engine-breaking, so I try to avoid it.

If by this you mean you simply don't enjoy it, fair enough. Ride for your enjoyment. ✌

If you have a concern about the engine braking, I think you can let that go. It's fine to do. Some of us rarely touch the brakes.

 

[ovtover]

If by this you mean you simply don't enjoy it, fair enough. Ride for your enjoyment. ✌

If you have a concern about the engine braking, I think you can let that go. It's fine to do. Some of us rarely touch the brakes.

good to know!! learning as I go here, and with no one I know personally ever having ridden a motorcycle.

 

[kentforrest]

good to know!! learning as I go here, and with no one I know personally ever having ridden a motorcycle.

A riding course is really valuable.

And you're fortunate to be learning in the age of YouTube with content providers like motojitsu and similar.

And forums. 🤣

 

[ARBOLMANO]

I’d double the ride course suggest. I take em when ever I can. More fun than a bag of snakes and the odds are good you learn something. A bad day when go to bed and not learned nothing all day. Also meet like minded souls. I’d be instructing if I hadn’t got sick.
Most find engine braking beneficial, it’s one reason for a slipper clutch really. Your brake pads will last longer though Pops used to say “brakes are cheaper than gears to fix”. There’s a line in there somewhere. And I so agree, this is an excellent time to ride motor bikes. The bikes are just amazing in modern times. And keep getting better.
Somehow you need data points to solve your issue. Maybe the dealer would loan you the scanner? The other way would be to start throwing parts at it, the “eighties method” when diagnostics were ****. Frightful method really and gets right expensive. A last resort really. Though if you found a bra with a 310 that you could swap parts, well that could work if anything “well that’s not it” sometimes finds it. Good Luck and stay with it

 

[fzfrank]

are you lugging the engine, how many rpm are you at when you coast?

It doesn't seem RMP-dependent and I'm not lagging it, but I'll note the RPMs next time I ride it. Now that I know how to trigger it, I can bring it to the dealer hot and see if a tech can take it out.

 

[fzfrank]

If an issue only shows after twenty minutes, that’s rough on technicians. You may have to get a scan tool and drive with it. Or try a different technician who can divest some time.
So hard to diagnose an intermittent issue.

Do you I need a special scan tool for a BMW motorcycle...or any motorcycle for that matter? I have a generic scan tool for cars, but do you have any recommendations for this bike? Thank you.

 

[ARBOLMANO]

I’m trying hard not to own a scanner for this unit myself. I’d bet money your current tool won’t talk to the bike. That would be too easy. Moto scan is popular. I’ve had the 911 tool it’s good. Somebodies bound to have real world time and chime in.
Call your dealer I’d reckon they would work with you to solve this. Nobody enjoys intermittent issues.

 

[kentforrest]

MotoScan is price friendly and does enough (so far) for my DIY efforts.

 

[fzfrank]

Here's a quick update. I'm on a 3-day trip on the Northeast Backcountry Discovery Route (highly recommended, by the way). The bike seems to run perfectly when alternating speed/throttle, but bucks pretty consistently when I'm applying constant throttle at highway-ish speeds. I went through about 3/4 quart of oil over a ~150 mile ride yesterday. The blue smoke isn't always visible, but when I started it up there was some, and when I restarted after riding it hard at high speeds, there was a lot of blue smoke.

Could this be the PCV valve? Does this bike have a PCV valve or something like it?

 

[kentforrest]

Here's a quick update. I'm on a 3-day trip on the Northeast Backcountry Discovery Route (highly recommended, by the way). The bike seems to run perfectly when alternating speed/throttle, but bucks pretty consistently when I'm applying constant throttle at highway-ish speeds. I went through about 3/4 quart of oil over a ~150 mile ride yesterday. The blue smoke isn't always visible, but when I started it up there was some, and when I restarted after riding it hard at high speeds, there was a lot of blue smoke.

Could this be the PCV valve? Does this bike have a PCV valve or something like it?

I believe CV is handled via the SAI system and uses a switching valve.

Those more experienced diagnosing engine breather problems can correct me if I'm wrong, but IME these tend to be associated with less narrow symptoms than yours. I'd expect rough idle, poor acceleration, etc. IIRC, you're just seeing issues in a specific mph range? Not necessarily specific rpm, but actual road speeds?

That seems more ECU/EFI related, as engine components shouldn't care (or know) about road speed?

The oil consumption is curious, and does line up with excessive internal pressure, true.

 

[porth]

The oil issue is curious, maybe some problem with piston sealing, what fuel type are you using, is there any pre-ignition? could a higher ron fuel solve your problem?

 

[fzfrank]

I'd expect rough idle, poor acceleration, etc. IIRC, you're just seeing issues in a specific mph range? .

My issues aren't speed specific. I believe that was from the original poster. I seem to have issues when I'm either using the engine to brake or riding along at a constant RPM using little throttle.

Interestingly, the problem was a lot better on the 3rd day of my trip. I burned little to no oil and there was much less bucking/stuttering. On the first 2 days (300 miles) of the trip, I probably burned 1.5 quarts of oil.

 

[fzfrank]

The oil issue is curious, maybe some problem with piston sealing, what fuel type are you using, is there any pre-ignition? could a higher ron fuel solve your problem?

I'm certainly willing to give that a try.