Not starting when hot....

[mattster]

Hey folks, looking to pick some brains here...

My Storm is refusing to start when hot..... First time it happened was after a proper blast to Oban. After a prolonged period of sitting in 2nd/3rd gear for the twisties, we pulled into Oban for a bag of chips... I realised I was parked like a tvat, so tried to start her up to shift to a better place.

Nothing. It didn't even really turn over, just a slight wheeze like you get when the battery is flat. After a few minutes of general poking and prodding, the call of the chippy was too great, so I left the bike to think about what it had done whilst I refuelled.

Got back to the bike 30 mins later, started up no problem at all! Took it a bit easier on the way home, no issues.

Since then though, it's doing it more often...

My initial thought is valve clearances.... it's done 38k miles and I have no idea if they have ever been checked! If there is no clearance on one (or more!) valves, then would there be enough force to prevent the starter from turning the bike over under heat expansion?

Anyone else had this?

Stripped the bike down last night while it cooled, so I'll hopefully get the clearances checked at the weekend anyway. If there's anything else I should look into, let me know!

Cheers,
Matt

[sirch345]

Matt, a good idea to get the valve clearances checked anyway, but I can't see that being the problem. If there is no clearance on one (or more!) valves as you put it, that would make it easier for the engine to turn over not harder, as the valve(s) would not be fully closing causing compression to be lost. (Less compression = easier to turn over).

Once you've done the valve clearances, I would suggest checking the charging at the battery first using a multi-meter. With the engine running you should be getting between 13.5 and 15.5 volts. It could just be the battery is getting done.

Do you have a finned rectifier on your bike

How old are the spark plugs It might be worth trying a new set.

Chris.

[oldbikeman]

When it is running is the motor free revving ,no partial seizure or cam chain whirring?

[mattster]

If there is no clearance on one (or more!) valves as you put it, that would make it easier for the engine to turn over not harder, as the valve(s) would not be fully closing causing compression to be lost. (Less compression = easier to turn over).

Once you've done the valve clearances, I would suggest checking the charging at the battery first using a multi-meter. With the engine running you should be getting between 13.5 and 15.5 volts. It could just be the battery is getting done.

Do you have a finned rectifier on your bike

How old are the spark plugs It might be worth trying a new set.

Chris.

Cheers Chris, that makes perfect sense! For some reason I'd had it in my head that the lack of clearance would make it harder to turn!

I'll check out the battery once it's all back together again - it's never given me a problem in the year i've had the bike, but it looks as though it's been in place for a few years now.. could be ready to be changed.

It's got a finned rectifier and it had a new alternator coil and spark plugs fitted just before I bought it (I got the old ones in the sale!)

Will report back once it's all checked out

[mattster]

When it is running is the motor free revving ,no partial seizure or cam chain whirring?

It seems free revving to me - nothing out of the ordinary in terms of whirring/rattling.... it does backfire a lot on the overrun and farts through the airbox a fair bit...

[benny hedges]

airleaks. probably around the carb rubbers or perished / cracked vac hose(s)

the carb rubbers may be cracked & decaying too - they dont last forever.
it'll fire up ok on choke but it's too weak without it.
could even be a blocked or partially blocked pilot jet.
it's fuel related though id say, bad fuel starvation.

[tony.mon]

Knackered battery.

Get it tested, or borrow one, but meter out the alternator outputs first just in case the RR's gone.

Hot battery won't start a bike, if it's overcharging, but will be better once it cools.

[mattster]

Cheers folks,

Valve Clearances checked last night - all nicely in the middle of the tolerances

Carb Rubbers/vacuum hoses didn't seem perished, but the carb clamps were a little loose... all put back correctly and tightened up nicely. Took the opportunity to get the balancing hose in place on the front cylinder too

Will measure the alternator outputs tonight, might also 'borrow' the battery out of a mate's storm while he's away with work....

[mattster]

Hey folks!

Finally got around to checking the voltage outputs on the bike about a week or so ago - with the bike idling & revving, the voltages were all spot on, but when switched off, the battery was hovering around the 11.9V mark...

So, new battery bought and fitted (went for the bigger varadero one!) and job's a good 'un! Thanks for the help folks, now just need to get the weather to stay reasonable to let me out and about!

In other bike news, the Thunderace has sold (I do miss it.) but it has left me with a bit of spare cash. I'm going to be on the lookout now for a slightly worse for wear bike to rip apart and fettle over the winter months. If anyone has any tatty storms they'd like to part with, give me a shout!