Hard to start when warm

PaulBK7

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Can anyone suggest why my bike turns over relatively easy when cold but just about manages to crank over when warm (say after stopping to fill with petrol) the starter engages then there a very short pause then it seems to overcome the resistance and cranks over?.
My first thought is battery but I would expect the problem to be worse when cold?

Any ideas please

Cheers
 
Have the battery properly checked using the most up to date systems that are able to "ping" each individual cell. Check volt drops across each earth point when cranking.
If all good there maybe the starter is goosed. :comfort
 
Not much use

Had a girlfriend once who was very hard to start when cold

I'm not sure that helps, though
 
Could be the starter motor gets tight once hot, or maybe a high resistance contact somewhere eg starter relay wiring, cabling etc. Maybe a strip and clean of starter motor and associated wiring with a dab of grease on terminals as preventative maintenance.

Could also be that your compression is higher with a hotter engine suggesting the battery is struggling to crank/compress.

As you stated, the battery should struggle when colder so it's unusual.
 
Make sure all heavy contacts from battery to starter motor are clean and tight. Starter brushes dont last for ever but are usually easy to change. Im not familiar with the BMW starter but it should be easy enough to check.
 
I have the same problem, though it's never failed to start so far ........ Touch wood.

I had the battery checked and was told it is ok.

Will try it with the side stand up to see if that makes a difference.

Will keep an eye on this thread as well.

Cheers.
 


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