I was wondering how much the thicker oil would also play a role?

As far as oil, I believe that would depend on the viscosity rating of the oil, and how fresh the oil is. If you're running a multi-weight oil like 10W/40, then in colder weather the oil will react like a 10 weight oil to allow better flow and easier cranking. But as multi-weight oils degrade, the polymers that are added to create the multi-weight break down and the viscosity starts to revert back to the heavier weight of the base oil. That's called "sheer." That's why old oil in cold weather causes sluggish cranking.

There's a simple formula to determine a multi-weight oils ability to resist sheer. You divide the second number by the first number; the lower the number means the oil has less polymers. Less polymers means less sheer.

For example:
10W/30 (30 divided by 10 = 3)
20W/50 (50 divided by 20 = 2.5)
The 10W/30 oil will sheer and lose it's multi-weight characteristics faster than the 20W/50 oil would.

Getting back to your original question and assuming your oil is fresh. I don't think that's your sluggish cranking problem. My money's on a weak battery that's probably on it's way out.
Good luck,
Phil

 

As far as oil, I believe that would depend on the viscosity rating of the oil, and how fresh the oil is. If you're running a multi-weight oil like 10W/40, then in colder weather the oil will react like a 10 weight oil to allow better flow and easier cranking. But as multi-weight oils degrade, the polymers that are added to create the multi-weight break down and the viscosity starts to revert back to the heavier weight of the base oil. That's called "sheer." That's why old oil in cold weather causes sluggish cranking.

My money's on a weak battery that's probably on it's way out.

Do you want my address to send a cheque to, or just a bank deposit?

I can't recall the oil off hand but may be a 15w50. Probably haven't done 200km since the last oil change so it's pretty fresh.

The battery is holding charge (12 hours sitting overnight outside (covered) through hail and sleet and this morning took maybe 5 seconds for the charger to say it's full) and can crank for a while if I leave the kill switch off (also tried this morning). It's only 4 years old, good brand and AGM.

Another factor I probably should've taken into account is the state of the starter motor itself - 1986 probably OEM, good chance it has original brushes... What's the odds it's feeling a bit tired, it's own grease is well past it, and with the cold perhaps the brushes aren't contacting the armature as well as they should? When the storm clears, if it's still cold, I should take a jug of hot water down, tip it over the starter, and see how it goes (yes I'll ride in this weather if I have good enough reason, but I ain't gonna play around with the bike for the sake of testing a theory! )

I remember my old Shadow was also horrible to start on very cold (for us) mornings. Next battery I think I will see if I can find something with a higher CCA especially for winter. That said this battery will crank my car better than it will crank the Shadow!

The temps here are low especially for this time of year. Where I live I get some of the worst of the colder winds, and the system we have atm is bringing about mid-late winter temps and weather. In fact I believe it's colder today here than our coldest day last year (excluding frosts)!

 

If your 1986 is like my 1983 the kill switch will cut power to the coils but the starter will still crank. It makes it easy to do a load test on the battery.
Our starters draw about 80-90 amps so put a meter on the battery and see if it will hold up above 9.5 + volts while you crank it for 15 seconds. My old battery would stay charged and look fine but could not hold up under a load.

 

This one does let me crank (whereas my other one doesn't, both 86). So far as I have tested the battery is holding up fine. Holding a charge overnight in <4C weather (12 hours), giving enough charge to start the bike after 20 seconds cranking. Which is why I thought the oil might have something to do with it. But with a little more thought I'm wondering if the starter itself is part of the problem. Good chance it's original and original brushes, so any wear on there or solidifying of the grease inside could be leading to the issue. If the weather clear some I'll pour some hot water on it and see how it performs. Gotta stop having hail and sleet-like stuff blowing in before I'll do that. Not keen on doing it in the rain either!

 

Hi, My bike isnt crazy about cold. Lots of choke and very slow warmup.I tried 20w50 for summer and still have it in at 39and below.It's just to thick for cold weather. Back to 10w40.

 

Did some testing today.

First, no charger since early yesterday.

She started OK this morning. Still sluggish on the cranking but started OK. Choke but no gas. Outside temp was a bit warmer, I think around 10-12.

I had 2 stops over a distance of about 20km before I got to the supermarket for my shopping. I also caught up with a friend while there, and spent a good hour or so away from the bike which I parked outside. When I got back the engine was still warmer than the surrounding air, but probably only around 20deg C, not much more than that.

Turned everything on (all lights, gps etc) and loaded the groceries into the bags. Then made sure the kill switch was OFF and cranked for about 20 seconds. Turned the key off, waited a couple of minutes (cooldown), cranked another 20 seconds, key off another wait, and a 3rd lot of cranking. At the end of the last lot the display by the bars was showing 10.5v so the battery would've been around 11.5 (the display is around 1v lower than measuring it at the battery). After a final wait of a couple of minutes I turned her on, left everything on still, set the kill switch to "run" and pressed the starter. Only took a second if that for the bike to fire.

At all times the cranking was nice and fast like she would be on a hot day with a full battery. The battery did fall below 9.5v on the display but still would've been at least 10v at the battery itself.

Maybe tomorrow (if I go out anywhere!) I'll try just hitting the starter with a jug of hot water, see if that makes a difference.

This isn't a problem, she's still starting OK even though the cranking itself seems sluggish when things are cold. Just one of my many ideas to actually test what is going on with something before (if I ever decide it's a problem) tossing money at stuff that might not fix the issue.

 

After I put a MOSFET r/r on my '98 1100 I got this battery (LFX19A4-BS12) not cheap but I've started my bike in 25*f after sitting outside all night and it fires right up. It can also sit for 2 or 3 months in the winter without having been started and it will fire right up. 285CCA do that, been on my bike for 4 or 5 years now and I have yet had to put a charger on it.

I run 15/40 year round

ROD

 

285CCA will start plenty of things! Mine's originally rated at 160, not sure it outputs that all the time now.

The bike starts OK, just sluggish cranking. It's like there's a ton of power in the battery but something else is slowing down the turning. Oil viscosity, hardened grease in the starter, worn brushes, combination.... I expect a cold night so hopefully in the morning I'll remember to try with the oil. Today was warmer and sunny so there was not even a slight issue starting.

 

Shorai shows this battery(LFX19A4-BS12) for the VT 700, 750 and 1100 models. I have over 100k miles on my '98 VT1100T with all the original parts except the r/r. Those 285CCA spin it over like a top, hot, cold and anything in between. Starts up every time, thats one thing I don't worry about anymore. Well till the battery does finally bites the dust.
https://shoraipower.com/products

ROD

 

Did the "water test" this morning.

Ok, so it's not as cold as I was hoping (I was hoping for the forecast frost, instead we got maybe 10-12C) and by the time I got my backside out to the bike the sun was already peeking through the cloud cover, but the tarp was still over the bike.

First test was 5 seconds of cranking with the ignition off, just noting the 'rhythm of the winds' (wind as in coil windings, not wind as in that stuff that blows), and while not bad it was slower than a couple of weeks back.

Then I slowly poured around a litre of recently boiled water over the brush end of the starter motor and tried again. There was a noticeable increase in the cranking speed.

So I've got a good possibility of what is going on here now. Starter is old, brushes and perhaps bearing surfaces worn, possibly grease getting old and hard when it's cooler, all contributing to a motor that's harder to work when cold. Adding heat causes some expansion of some metal parts and perhaps softening of the grease, allowing the motor to work a bit better.

These motors have a lot of torque, but a brush failing to make good contact and other factors combined with the overall low gearing could easily lower their performance. The winter chills we've had the last few days (snow on the Rimutaka ranges in April????? Not seen that in a while!) are enough to make a difference.

As stated here, the battery itself is still quite fine. 60 seconds of cranking with little overall voltage drop or change in the cranking speed of the bike. I was quite sure of the battery's health going into this, which is why I first gave oil a suggestion (forgetting about the way motor oils work and thinking of other oils that can "thicken" as they cool).

I'll look to refusbish my spare starter and get that into the bike, and hopefully see what a difference is made there. God willing I can get it out without having to remove the driven gear first! (not a problem on the spare engine but means lots of opening stuff on Envy which I don't want to do

 

I have taken a lot of starters apart that were to be replaced . All of them have worn brushes and a large quantity of carbon dust in the rear cover area. That can cause a resistance to contact. Especially the ones that would not turn until you smack it with a heavy tool and then it spun the engine over.

I bought a set of these rebuild parts cheap on ebay to have as a spare. I was impressed how nice of quality they appear to be for the price.

https://www.ebay.com/itm/Starter-Re...0C-Shadow-1984-1987/271489351201?hash=item3f3606be21:g:3AEAAOxy7vJTcosR&vxp=mtr