Winter starting

[BigJim]

Someone here must own a BSA that starts readily on a cold day.

Famous last words: Mine.

Ha, mine WAS pretty good. But then a good swing was generally easy due to the lack of compression!
Nice of GB to hex his bike so no others would be harmed in the making of this thread.
Assume your's is easy TT?
 

[Triton Thrasher]

Assume your's is easy TT?
 

Mine doesn’t properly count, because it’s another popular marque of 650 twin, but why wouldn’t they all start the same?

My “tuned” T110 starts easily in that it will start if you can kick it over.  On a cold morning it requires tickling of both carbs until petrol is liberally flowing out and when it starts on 1/4 throttle, I have to keep revs up for a few seconds, or the engine will stall. There are no air slides.

The oil, which don’t think is all that relevant, is synthetic 20W/50.

The compression ratio is 7.5:1, but the rings seal well and a hot compression test shows 170 psi, so in that way, with an arthritic knee, it’s not so easy to start!

 To kick it over, I free the clutch, find compression, set the kickstart to near horizontal and leap on it.  This is done astride the bike with the stand retracted.

[Butch (cb)]

Mine is out in the bike port under covers. Oil is straight 50 so probably like treacle at the moment. I'll not be stepping on the kicker this side of Easter I don't suppose, and may not even pull the cover back between now and then. I've got no place to go and no reason to go there, and I don't hold with firing my motors up just for the sake of it, or a warm through, or whatever.

When I do get to pull it out I expect it to have wet sumped hardly a drop, and fire up within a kick or two. But maybe I'm setting myself up for disappointment. 

[Triton Thrasher]

Someone here must own a BSA that starts readily on a cold day.

Famous last words: Mine.

Should be ok if the bike didn’t hear you say that.

[Angus]

Frankly, a bike that takes twenty kicks to start is worthy to be an object of unkind humour.

I saw this and smiled and waited for the banter to start (note this is in chat offtopic), I would have joined in as well as the Norton defiantly had many many more kicks.
So today as the general opinion was there must be something wrong, I started the A7 again. The same process as yesterday first kick and started, it is one degree warmer but here are some points.
Bike is reliable all summer first kick starter.
Bike will start reliably if started more regularly e.g not left for two weeks (not sure what the period is)
I always drain the carb float, by letting the engine run with the taps off. This means the petrol used for startup is ‘fresh’ out of the tank whether it is started every two weeks or every other day.
I always let the float fill and then tickle until petrel comes out of the tickler vent
I have never used the choke, well I do try when it is hard to start but it never seams to make a difference.
All the above points to wet sumping BUT the A7 does not appear to wet sump. In the past I have drained the sump to check when it has been hard to start and there is not much in there no more then when I do oil changes.

I am a very logical person it makes no sense to me why leaving a bike for two weeks in colder weather should effect the starting, unless I have missed the answer in amongst the posts.

ps I am not desperate for an answer I know they will start and I know that when they are getting used they will start easily. plus it is good exercise 

[RDfella]

So an engine that's hard to start in winter will start easily in summer. What's changed? Mechanically, nothing. What has happened is twofold: the petrol vapourises less easily and droplets of petrol aren't going to be ignited by a weak spark. Secondly, the engine is going to turn over more slowly due to oil viscosity. Oil in the bore will drag on the pistons, oil on crank journals, in the gearbox - even the primary chain - all are going to combine to ensure the engine turns over more slowly on the kickstarter (or electric starter where applicable) when temperatures are low. Now a magneto produces a poor spark at low revs. Reduce those revs even more and it's quite possible that in winter there's barely any spark at all. Solution? Don't ride in the winter. I don't, it's too bloody cold and I only ride for pleasure. Besides, it's dangerous riding with a coal fire on your petrol tank and a large glass of brandy in your right hand.

[berger]

I agree with RD on this one , I have a chain soaking in straight 50 oil and it's like treacle, so the oil viscosity has a lot to do with how fast you can spin the engine and how good the petrol and ignition are.

[Triton Thrasher]

Well I daresay that if you do your kickstarting in some sort of slow motion, it might not spark or start,  so don’t do that!

Just by the way, SAE50 (Castrol GP50) oil is not suitable for winter use in the U.K.  It gets so thick that it may not flow sufficiently, under gravity, from the tank to the pump.

[Angus]

Thanks again for your replies RDfella, berger and TT
RDfella, berger
No it is not a difference between summer and winter it started first kick today and would do I am sure tomorrow, but if I leave it for a couple of weeks it will be a pain again.
so its not oil viscoity, week spark or poor fuel vaporisationas there where all the same as yesterday 
As below everything points to wet sumping but I am fairly sure the A7 does not do that. Also all my bike do it the including the model 7 and the A10 and they will all start if started the day or a couple of days later.
I will do a trial and try starting the A7 with slowly larger gaps and see where the cut-off appears to be. I will also check it for wet sumping again.
I have just thought of another common denominator that is the kicker (ME) but I am sure I am doing the same thing all the time summer winter, yesterday and today
Also as below I dont need an answer, it may just be old bikes and mine in particular and there is no logical explanation.

[Black Sheep]

Perhaps ageing knees are creakier when it's cold...

[Seabee]

The SR will start in any weather with minimal effort. One trick I do, is to run the carb out of gas when shutting down. That way I get a "fresh" dose from the tank. If I let it sit in the carb, it seems to go bad much quicker and doesn't have enough oomph left in it to start. I use Stabil over the winter and have run the same fuel with no issues at all.

[jhg1958]

In winter the refineries spike petrol with short chain hydrocarbons even as low as butane.  These happily dissolve in the petrol but will preferentially vaporise,  hence the myth that petrol goes off with age.  These volatiles will help an engine start.  If you are using petrol bought in the summer it will have less of the volatiles and be harder to start.

Petrol left in an open vented container will loose these volatiles making engines harder to start.

This maybe a contributor to hard starting but all the other great points in this thread will work against you.

Try not to leave petrol from the summer in the tank. Top it up with fuel from a sealed container.. it may help but only one kick less. 

Best of luck

[Joolstacho]

What price Electric starter? 

[olev]

Listen to Swarfy,
<Difficult starter? Swallow your pride and invest in a can of Start Yer *asta*d.>
I've got a stuffed hip and have used it for years for a first kick start-up.
Other than a push, it was the only way to start the Greeves (RIP) which was a real pig. (in more ways than one)
cheers

[Joolstacho]

In winter the refineries spike petrol with short chain hydrocarbons even as low as butane.  These happily dissolve in the petrol but will preferentially vaporise,  hence the myth that petrol goes off with age.  These volatiles will help an engine start.  If you are using petrol bought in the summer it will have less of the volatiles and be harder to start.

Petrol left in an open vented container will loose these volatiles making engines harder to start.

This maybe a contributor to hard starting but all the other great points in this thread will work against you.

Try not to leave petrol from the summer in the tank. Top it up with fuel from a sealed container.. it may help but only one kick less. 

Best of luck

What country are you in? -I'd imagine it would make a difference.