Caught out by high compression, warm starting issue on R1250GSA

Andy63

Andy63

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Evening all, was out today running errands so decided to take the bike (for easier parking). whilst out i decided to go for a ride then do the errands.

Durig the ride i had a tyre pressure warning on the TFT so headed to the nearest garage to check the pressures. On arrival I switched the bike off, then found the airline wasn't working :mad:
Went to start the bike and it failed to start. Now i have had this before, but the bike always started, when the bike was new and more recently since having the valves adjusted. I tried to start the bike probably half a dozen times but no go.

The bike is a 2021 (24000 on the clock) and had from new, in that time it has never failed to start. Its still on the original battery, so i'm thinking the battery has no longer got the power but whenever I connect the C-Tek it goes to full charge within a minute. So to my mind the battery is good.

Left the bike where it was and got the bus home and collected it about an hour or so later, and it started straight up first time.

Have done some Googling after getting home and found this thread https://www.ukgser.com/community/threads/hot-starting-problem.343548/

So I now understand if you leave the bike for about 30 min, it should start up after the engine has cooled. I am now looking at getting a Yuasa YTX14H-BS high power battery.

What i am thankful of is this didn't happen a couple of weeks ago whilst away in France.

As a side note I didnt get the valve's checked until 22000 miles (as i thought it was due at 18000) hence not had this issue between the bike being new and more recently before the valve check service.
Might have a conversation with the mechanic to see how much to loosen the exhaust valves off tad.
 
Last edited:
Pukmeister said:
The Ctek will charge the bike battery to its full capacity, but that capacity isn’t the same as it was when new.
Click to expand...
Yeah I'm understanding that now, the battery was tested a couple of years ago but came back with flying colours. So i put it back in the bike.
My experience with motobike batteries is generally 3 years then they are done, so i am very happy to 5 years out of this one but it's now time for a new one.
 
I’ve had this same scenario on my 2019 GSA since I got it. Months without any problem, in all weathers, then bang, a flat battery when the engine is hot.
I got a new Yuasa at about three years with no good result. The engine is at no higher compression at one time than any other, so I really don’t get loosening exhaust clearances when the manufacturer has strict tolerances.

I just carry a jump pack and have it restarted in less than a minute, no dramas.
 
When I had my GS1200 I did all my own services, but when it came to the valve checks they were always well in spec and never needed adjustment. The wet head engine very rarely needs the valves touching.

I think your first port of call is replacing the battery.

Good luck.
 
Your 14H battery is a tad under par

The 16H equivalent is the same pack size with more CCA.

Alternatively you could go lithium for even more BPB or hybrid lithium/ AGM

For max BPB :)

Lithium has its own foibles,
Needs a special charger & won't charge under 0 degrees ( but they will start down to -20)

And very cold starting is a 2 step process

@Puckmeister, can give you the lowdown on hybrid lithium AGM batteries
 
Santa-2512 said:
Your 14H battery is a tad under par

The 16H equivalent is the same pack size with more CCA.
Click to expand...
I changed mine for the Yuasa 16ah, after 2 years it was sluggish. Changed to the hybrid Motobat and it's been great since.

I too had the same issue with parking up for 10 minutes and it not starting, not since the battery change.
 
Pukmeister said:
The hybrid Lithium/AGM battery is superb but a little expensive.

For me, confidence and reliability beats price every time.
Click to expand...
I bought the exact same battery as Adam here and again absolutely no issues since!!
 
I had the same problem on a June ‘23 GS.
A friend rescued me with one of those booster pack thingy’s. Rode to dealership and it started perfectly multiple times. Anyway, BMW changed the battery and no problems since. As soon as it goes into ‘Ducati start mode’ I’ll change 😂
 
At this point I think I've an expertise in this. If the bike is not trickle charged and just sits up the battery can get low naturally . If you take it for a short spin OR a longer spin and you run for example heated grips or a heated jacket the alternator does not get enough time to charge the battery up to an effective starting cycle . I.e just higher enough for a half a crank but not enough for a few rotations.

There is a very simple fix. Leave the bike sit for minimum of 10 minutes without touching it at all after your last crank. Even 15 minutes minimum. It will allow the battery settle and it will start absolutely fine. I've had this occur a few times. And I've replaced batteries I've paid good money for decent trickle chargers.

The only times this happens to me now is if the bike hasn't been trickle charged and it's sat for maybe 4 days and I proceed to do a short run. It seems to be purely down to battery not getting up to a high enough value . (Longer run or no peripherals, or was trickle charged to begin with)

The leave it alone trick works a charm hasn't failed yet. Your alternate if you don't wish to wait, carry a battery charger like the noco.

I don't believe this has anything to do with compression tbh. As everytime it occurs the battery value is around 12.1 or .2. And if left it comes up to about .4 which seems to be when crank can fill get going.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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