Hesitant to turn over when hot

[Pukmeister]

My bike is hesitant to crank on the starter when restarting from hot, such as after a stall etc. Yesterday I hit the killswitch at Brockenhurst railway junction until the train passed and the gates lifted. On cranking the bike really struggled to turn over and fire. Starting from cold or after a decent rest stop isn't a problem.

Has anyone else experienced or cured this? Mines a 2008 GSA.

I have a brand new Motobatt battery to fit and considered stripping and cleaning the starter motor but as I have an IAM test this week I don't want to bugger anything up prior to the test date.

I also seem to have a bit of vertical play in my FD bearings when hot, typical that I find such things out now when I really need the bike.

 

[Nice 'n' Fat]

I'd fit the battery and see if that cures the problem

 

[ianf]

Yep, 2011 TC does it too. It's usually after stopping for something at the shops. It always fires, but cranks slowly. Moaned about it at first service, and got a new battery. Still does it though on occasion.

 

[autogs]

my 2012 gsa does it occasionaly but always starts,there seems to be no rhyme or reason i dont worry about it now.

 

[cocker]

the 09 bike i test rode from the dealer did it while i was out on my first go of a gsa, and my 2012 gsa has done it on the odd occasion from new, for some reason it hasnt been anything that has worried me, i always have the gut feeling that the bike will start and its no big problem, i remember when i started riding sherco 4t trials bikes they were a bugger to start when they were hot,

 

[solidstate100]

My 09 GSA has done this a few times. It's generally the heat from the engine increasing the resistance of the windings in the starter, meaning more power is required from the battery to crank it.

If your battery is a bit below par this can excaberate this, but even when I fitted a new battery it still happens very very occasionally.

 

[Pukmeister]

Fitted the Motobatt, stuck it on the CTEK until fully charged, and measured side play at rear wheel rim with a DTI at 0.25mm so well within spec (can just feel the play between 6 and 12).

A quick blat up the Meon Valley on fairly empty roads, stopped a couple of times and she fired up much more readily (although still slower than cold) so new battery was worth it.

Will change FD oil and lube splines one evening this week.

Incidentally with the TPS reset after fitting the new battery, the throttle response was velvety smooth with no more driveline clunking. Maybe a new TPS might be of benefit?

 

[Mav]

My 09 GSA has done this a few times. It's generally the heat from the engine increasing the resistance of the windings in the starter, meaning more power is required from the battery to crank it.

If your battery is a bit below par this can excaberate this, but even when I fitted a new battery it still happens very very occasionally.

This is the issue - had it on my HP2. As the starter motor gets older, the affect of heat making the starter motor less efficient gets worse. A fresh battery can help... but if the starter motor is on the way out, you're still going to have the issue in the end.

 

[Pukmeister]

Might strip it and clean/undercut the commutator segments then wash the carbon dust off the windings and check/replace the brushes.Thanks for the advice. A job in the man cave one evening.

My old 2004 bike with the plastic starter cover never had the same fault despite having more than twice the mileage.

 

[Bendy toy]

If winding resistance was the problem most vehicles would have the same problem.

Most likely it's worn starter brushes and dirty commutator. Its unlikely to need the insulation undercutting but the slots may need scraping clean with a jeweler's screwdriver.

Mine has begun to do the same. Does anyone know if starter brushes can be bought separately?

 

[Pukmeister]

I have a few carbon brushes from DC motors as come in handy spares, can always file down oversize ones to fit so long as the length of carbon brush and the tails are adequate. Not looked in the RS/Maplin catalogue but I expect they have them or a local electrical repair specialist can source something if not available from Bosch or BMW.