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Hard starting

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Try turning the power on then just bumping the starter and letting off. Then hit the starter again it see if it starts up quickly as it did before.

I'm sitting at about 6k miles and noticed this issue after a couple of changes 1) I put in some injector cleaner (Royal Purple) 2) I changed the DWA settings to off 3) I replaced the DWA battery.

I suspect this issue is an injector leaking down and air getting in the system. This only happens on mine after sitting all night. I also tried a whole tank of 90 ethanol free fuel and replaced the battery when it died recently with the 800 CCA which turns the bike over way better. I also noticed that if you hold the starter down on an overnight cold start it will not start, but letting off then hitting it again it starts right up. I experimented with mine and so far two small bumps on the starter gets it going every time.
 
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Here's another test to see if the injector leak down may be the reason for the hard starting.

Test A (ambient temperature):
  • Start R18 in the garage and immediately turn it off after 5 seconds or so
  • Let it sit for 24 hours in the same conditions/weather e.g. garage
  • 24 hours later see if it starts from the first button push
Test B (operating temperature):
  • Start and ride the R18 for at least 30 minutes to make sure it's completely up to operating temperature
  • Let it sit for 24 hours in the same conditions/weather e.g. garage
  • 24 hours later see if it starts from the first button push or if it requires the two start method mentioned above
Fuel levels, types, grades, etc. do not matter in the above tests. My hypothesis is when the R18 is hot that's causing the injector to leak-down so the system has air in it and is no longer primed. In the ambient temperature test I have observed that the R18 starts with a very small starter bump like it did before the hard starting problem came to be.

Also note that Test A and Test B need 24 hours for the R18 to sit. Just getting it up to temperature then trying the test is not helpful since the R18 will start right up and needs heat and time for the injector to leak down.
 
My 23 TC started having a starting issue as being described on a cold start. One day filling up with fuel I noticed a discoloured residue on the lip of the fuel tank over which the gas cap fits. I cleaned this off with a rag. I suddenly didn't have a starting problem any longer. I can't explain it but it worked and has continued working for me. Just give the lip and the gas cap an occasional wipe with a dry rag. Maybe there is some explanation but I have no idea what it may be other than a loss of vacuum seal (if there is some vacuum in the fuel system).
 
Jago said:
My 23 TC started having a starting issue as being described on a cold start. One day filling up with fuel I noticed a discoloured residue on the lip of the fuel tank over which the gas cap fits. I cleaned this off with a rag. I suddenly didn't have a starting problem any longer. I can't explain it but it worked and has continued working for me. Just give the lip and the gas cap an occasional wipe with a dry rag. Maybe there is some explanation but I have no idea what it may be other than a loss of vacuum seal (if there is some vacuum in the fuel system).
Click to expand...

Mine is pristine with nothing on there. Your case could also be a related indicator of fuel aeration in the pump, injectors, or fueling circuit whereby you don't have a primed fuel circuit that causes first try hard/no starts. Mine is 100% reproducible with Test B above. The fact that most reports of this problem seem to be at low 3-6k miles and heat makes me suspect the injectors or pump are either dirty or degraded in some way (e.g. ethanol) causing this problem.

It's a euro bike and they have different fuel than the US does, plus I've personally seen problems on a Ducati that had unfixable fuel gauge issues due to ethanol. I think I recall seeing reports of other BMW models (GS) that fuel pumps were problematic in the US.

Connecting more dots with empirical evidence will likely reveal the truth of the problem. I have not personally looked at the injectors or checked the temps after a ride to gain more understanding. Nor have I looked to see what other models use the same injectors and pump.
 
Another culprit could be the charcoal canister.
The charcoal canister is part of the EVAP system, which recycles fuel vapors from the gas tank. If the canister is clogged or cracked, it can't do its job, leading to an improper air-fuel mixture in the engine, which can cause a no-start condition or hard start. Sometimes overfilling the gas tank can send the excess fuel to the canister.
 
Most of the parts we are discussing are all covered in the US under the EPA emissions warranty of 80k miles/8 yr. warranty. I suspect those who took their bikes in to the dealer got nowhere since mechanics are flat rate and not paid (nor can they afford to waste time on it for free) to root-cause problems.

My bike is outside the main 3 yr./36 mo. warranty so I'd have to be very convincing for them to look at it. I'd expect someone still under the main warranty with a 100% reproducer (Test A/Test B) would have little trouble getting them to do something about it. Alternatively, an EPA complaint or some sort of class action would be the next likely motivators for BMW to root-cause and resolve the issue.

@Anibal it looks like you're near the EU region with likely similar fuel. Do you, or anyone you know in your region, have the hard/no start condition on the R18 after operating temperature and sitting for 24 hours?
 
@u20251009
I have been very fortunate to have enjoyed 3 years of trouble free biking with my R18. We have E10 (10% ethanol) fuels here in the UK but I exclusively use Shell V Power E 5 as this is the one I consider to be the best available fuel. I use my bike to commute 3 days a week on Tuesday, Thursday and Friday and on the occasional Sunday if the weather is favourable and I fancy meeting friends at a biker’s hangout. Each ride will be at least 90 minutes each way and I have never experienced any issues with my bike, nor have I heard any one around here mentioning similar issues. Having said that, all the guys I know avoid E10 like the plague. I do believe ethanol plays havoc on rubber seals, injectors, carburettors and the entire fuel system for that matter. I also refuel my bike using the side stand to ensure an air bubble remains in the tank, not a fan of refuelling with the bike upright. I am not saying what I do is right but so far I have not had any issues with the R18 or any bike or car I have ever owned.
 
Anibal said:
Another culprit could be the charcoal canister.
The charcoal canister is part of the EVAP system, which recycles fuel vapors from the gas tank. If the canister is clogged or cracked, it can't do its job, leading to an improper air-fuel mixture in the engine, which can cause a no-start condition or hard start. Sometimes overfilling the gas tank can send the excess fuel to the canister.
Click to expand...
I knew their was a valid reason why it had to be removed apart from aesthetics.
 
Anibal said:
@u20251009
I also refuel my bike using the side stand to ensure an air bubble remains in the tank, not a fan of refuelling with the bike upright. I am not saying what I do is right but so far I have not had any issues with the R18 or any bike or car I have ever owned.
Click to expand...
Spot on.

The R18 is ok with E10. Rubbers and all totally prepaired for it.

Furthermore the fuel system it pretty much impervious for aging of modern fuel.

The issue with ethanol is the lower caloric value. It means less energy when burned is less power.

The EVAP means no fuel vapours when put indoors.

I tank E5, EURO98 if possible. No starting issues.
 
Boritch said:
Mine starts strong since the new Lithium LiFePO4 battery replacement.
Click to expand...
I've dismissed the battery replacement root-cause as coincidental. I replaced my original OEM battery when it died recently with the Antigravity ATX30 RE-START Lithium Battery 880 Cranking Amps. The same hard/no start condition exists before and after the battery replacement. It's also 100% reproducible using Test A/Test B before and after the battery replacement.

The new battery with 880 CCA does turn the bike over better.

In my experience here's what appears to not be the root-cause based on my testing:
  1. new battery
  2. fuel load
  3. fuel octane
  4. fuel grade/type (E10, ethanol free, 86, 87, 89, 90, 93, etc.)
  5. dwa settings

I suppose I could try a modification of Test A/Test B by removing the fuel cap and observe the results. Coupling that with the EVAP removal I guess would be my next steps to isolate this issue.

I guess stay tuned this may take me a couple of weeks to work through a test matrix.
 
u20251009 said:
Try turning the power on then just bumping the starter and letting off. Then hit the starter again it see if it starts up quickly as it did before.

I'm sitting at about 6k miles and noticed this issue after a couple of changes 1) I put in some injector cleaner (Royal Purple) 2) I changed the DWA settings to off 3) I replaced the DWA battery.

I suspect this issue is an injector leaking down and air getting in the system. This only happens on mine after sitting all night. I also tried a whole tank of 90 ethanol free fuel and replaced the battery when it died recently with the 800 CCA which turns the bike over way better. I also noticed that if you hold the starter down on an overnight cold start it will not start, but letting off then hitting it again it starts right up. I experimented with mine and so far two small bumps on the starter gets it goin
Click to expand...

800CCA Battery? What brand and model? Is it a direct fit, same physical size and terminal placement? My 2021 R18 Classic seems due for a new battery.
 
BAD MIKE said:
800CCA Battery? What brand and model? Is it a direct fit, same physical size and terminal placement? My 2021 R18 Classic seems due for a new battery.
Click to expand...
Yes, direct fit factory replacement - same size as the factory battery.

Antigravity ATX30 RE-START Lithium Battery
antigravitybatteries.com

ATX30 Lithium Motorsports Battery

Hi-Power lightweight ATX30-RS lithium motorcycle/powersports battery with RE-START Technology (built-in jump-starting). Replace lead/acid YTX30. 880 CA!
antigravitybatteries.com antigravitybatteries.com
 
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