Bike wont start in cold weather

HI All, 

Apologies if this has been covered before,  here it goes,

Bike started having difficulties starting a little while ago, but only when it is cold / cold and damp.   I would give it a few goes and eventually, it would start.   (the starter motor is turning, it just doesn't fire up)

it has been getting progressively harder to start until this morning when I eventually got it to fire up for a brief second and then it died again.  I had to get the tube  

at first, I thought maybe it was the brushes, so changed those,  cleaned up the inside of the starter.  so I know that's not the issue. 
on a warmer day or just not first thing it starts a lot easier.  to be honest this just started a few weeks ago, up until then it started first time every time and was really reliable. 

any thoughts on this would be great,  it is due its mot but I can't even get it to the garage!

Could the battery degrade that quickly? would that even be the issue if it sort of works depending on the weather?


Thanks in advance chaps

Welcome!

What is your starting procedure? Are you using the choke? On mine I need to only need the choke on for a couple of seconds without opening the throttle but without the choke it will often die after a few seconds when the engine is cold.

Hi, 

I have tried it with no choke, half and full,  

Previous to this issue arising i never really used the choke, as soon as it catches i give it a couple of revs and then let it idle.
as it got colder i started using the choke,  same thing really,  starter button and as soon as it catches i give it a couple and then let it idle / warm up.   up until today i always got it started eventually,  once its fired up and going it idles alright and stays on.   if it does cut out (side stand switch)  it would start immediately,  i'm presuming that was because the engine was a little warmer?

- additional, 

when cold it has been idling quite low recently,  around the 800 / 900 mark,  once i start going it quickly settles at 1200 / 1300 at the lights

what ever you do don't go down the route of using easy start the bike will get addicted to it and then you are screwed you will be using it for ever more 

Here are some thoughts in no particular order:

It's sometimes a good idea to slightly 'turn up' the idle and increase the idle speed - this can sometimes help a bit, but I suspect this isn't the root of your problem.

Have you looked at the way the choke/enricher mechanism works? The handlebar lever pulls a cable and the cable pulls a bar. The bar pulls/pushes two pistons (one on each carb) which open the enrichment circuit on the respective carb. You should be able to look under the tank a the carbs and see the cable moving the bar, if you can see the bar moving then there is a good chance that the 'choke' is being engaged when you move the lever.

If you have a multimeter (which I suspect you do) then it is worth doing the basic resistance checks on the coils (Haynes has the various resistances). It is also worth measuring the voltage across the battery when the bike is cranking, although I suspect this is not 'it' either.

Have you changed/checked the plugs recently (or ever)?

Have you checked that petrol is getting to the carbs (open the float bowl drains and watch the petrol spill on the floor/into a bucket)? - it's a dumb question, but...

Anyway, best of luck with getting it to go again.

Thanks for the tips so far, 

yesterday I left the cover off all day (i have to leave it outside) and it was a relatively sunny day here in London,   I got back about 7pm,  turned the bike on and it fired up straight away! but the engine did have that slow, cold, in need of choke sound.  

I don't have a multimeter at the moment so I thought I would just take out the battery and connect it to the charger,   it was registering as full, no charge needed.  (I was hoping this was it as it would be an easy fix)

So, I can now say 
it's not the battery (or very unlikely without multimeter testing)
it's not the brushes in the starter,
it has enough oil,

I have also given the various point that I could see a quick spray of wd40, I live next to a river so maybe the air is damper??

The choke system seems to work as when i adjust it whilst on the revs turn up and down respectively. 

Spark plugs,  will google how to get to those, not sure if i feel comfortable removing the tank (my mechanical training so far has been the school of youtube)

Thanks so far, any other thoughts are most welcome!

cheers

Tank off is easier than it sounds like it might be, fuel won't come pouring out as it's a vacuum operated. You can actually get the spark plugs out without removing the tank but not recommended as ideally you want to check beforehand there is not any crap down in the recess that could fall into the cylinder when you remove the plug! Worth finding a Haynes manual off eBay if you can as most jobs are explained in there.

What rpm does then bike idle at once warm? Probably worth having a look at the plugs as they can tell a story.... other than that unfortunately probably just a case of continuing your process of elimination...

Thanks for Help everyone,

Will defo get a Haynes before i attempt to take of the tank. 

@ceejay the bikes rpm when warm is approx 1300 which i believe to be correct. 

Saturday night the cover blew off and of course, the bike got soaked in the torrential rain.  I was nervous starting it on Sunday but it just fired up straight away!   Good news, however, i am quite confused. 

if it is purely just the cold temperature that makes it temperamental.  what could be weak link?

in the mean time,  i gave the points another spritz of wd40 and fed it some unleaded plus and its still starting first time,  no problem.

Given it seems to be working again, I'd get down screwfix (assuming there is one of them near you) and get one of these highly expensive meters (£10.99):

https://www.screwfix.com/p/lap-mas830b-digital-multimeter-600v/75337

This will allow you to see what the battery voltage is doing when the bike is running/starting which will at least mean you to rule out the battery/charging system from the equation.

You'll also be able to use the multimeter when you have some other electrical problem in the future. The batteries last for ages assuming you remember to turn it off!

The Haynes is really worth having. It *used* to be available in various easily accessible places online, if you can't find one then PM me and we'll sort something out.

@eternally_troubled thanks for tips. I managed to find a Haynes and will be getting a multimeter,
I'm planning on going travelling for 5 months and leaving my bike at my mother's in Devon, been reading lots of different advise on how to store a bike over winter, just wondering if this has already been covered in this forum?

edjasion wrote:@eternally_troubled  thanks for tips.   I managed to find a Haynes and will be  getting a multimeter,
I'm planning on going travelling for 5 months and leaving my bike at my mother's in Devon,  been reading lots of different advise on how to store a bike over winter,  just wondering if this has already been covered in this forum?  

As an absolute minimum I'd do the following (none of which are difficult):

* Oil/lube the chain

* Make sure the tyres are inflated to the correct pressures

* Remove the battery, charge it up and put it somewhere warm (in the house rather than in the garage if possible)

* Fill the tank with petrol (reduces rust), start the bike and then turn the fuel tap to off and let it die (this should remove most of the fuel from the carb bowls)

* Leave it on the centre stand (takes all the weight off at least the rear tyre)

Assuming you've got somewhere dry to leave it then it will be fine for 5 months.

When the time comes to revive it charge up the battery before trying to start it up - it might take a few goes to get it going.

Amazing, thanks for all the tips,  I've heard of people using a fuel stabaliser for long storage, something like stab-il or redex, is this advised?

I don't think that redex even makes any claims about being a fuel stabiliser, so I suspect that won't do any good (won't do any harm either, but...).

I did find this on the screwfix website - this at least claims to increase how long fuel lasts.

Personally, if it is only for 5 months I might not bother - having said that I doubt that sta-bil, redex, the thing I have linked above or anything similar will do any harm, so go for it if you want.

I've run bikes on fuel that's been sat in a tank for over 3 years with no problem. 5 months, I wouldn't even bother draining the carbs

Thanks all, 

I have done the following, 

Cleaned and re lubed the chain, 
Changed the oil and oil filter,
brimmed the tank, 
drained carbs
inflated tyres, 
removed battery
gave the whole bike a good clean, 
crossed my fingers, 

will update when i get back to the uk in April / May.

There is an article HERE regarding fuel stabilisers.  There are two issues with storing over winter, one being the loss of octane in the petrol and the other is the presence of Ethanol.  So look for a product that stabilises the Ethanol as it breaks down and produces water quicker than the petrol degrading.

I've used Wynn's Dry Fuel.  It treats 50 ltrs so used 1/2 a bottle.