Too Cold to Start, or Starter Clutch Going Bad?

[James England]

With the standard regulator rectifier, you wouldn't be getting any charge into the battery at idle, so you may well have weakened it a bit. The starter clutch does have to spin pretty fast to work properly.

Can someone enlighten me as to how the danged thing actually works? Ok little rollers etc but what's the importance of the oil to make the clutch grab?

[IanDMacDonald]

It was 49° coming into the house @ 11pm last night. The bike started on full choke at less than a second.

[blade-z]

Cold Starting

Here is my two cents worth. I personally believe this typically happens as the starter becomes old. Just like a car starter parts eventually wear out. The colder the weather the quicker the bike would instantly make the whirring noise. The whirring is obviously the starter motor spinning but is not engaging to attempt to start the motorcycle. Eventually the electricity flowing through the motor combined with the friction from turning cause a rise in the temperature of the starter. Typically this leads to the starter finally catching enough to crank the engine. Currently I have a wet cell battery installed into my 2nd motorcycle and it is obvious the battery itself was definitely not weak. I am going to purchase a replacement starter and will post my results after I installation and testing.

[IanDMacDonald]

I read an interesting thread prior to posting this that stated it's a combo of starter clutch, and cold weather, not the starter itself. I also read that you have to split the cases to install the starter clutch. Rebuild kit available.

[DGXSER]

Here is my two cents worth. I personally believe this typically happens as the starter becomes old. Just like a car starter parts eventually wear out. The colder the weather the quicker the bike would instantly make the whirring noise. The whirring is obviously the starter motor spinning but is not engaging to attempt to start the motorcycle. Eventually the electricity flowing through the motor combined with the friction from turning cause a rise in the temperature of the starter. Typically this leads to the starter finally catching enough to crank the engine. Currently I have a wet cell battery installed into my 2nd motorcycle and it is obvious the battery itself was definitely not weak. I am going to purchase a replacement starter and will post my results after I installation and testing.

This motorcycle uses a starter clutch, versus a starter solenoid like your car does. In either case the whirring sound you hear is the starter motor turning its gear, so the starter motor is doing what it is supposed to do. It just is not engaged with the engine to turn the engine over. Kind of like pulling the belt off of a belt driven motor. In a car and some bikes, there is a solenoid that pulls a gear into place to connect the starter to the engine. Often in those systems, a low voltage or ampacity from the battery will result in the solenoid not getting pulled in.

On these bikes, we have a starter clutch. Basically, the starter motor turns the clutch which throws the engagement pawls and they grab the primary shaft and spin it, spinning the crankshaft through the Hyvo chain. When you release the starter, the pawls withdraw away from the shaft, disengaging the starter from the engine. So, typically, if your hearing a whirring sound, then either the starter clutch itself is worn out, the pawls no longer grab the primary shaft, or your not spinning the clutch fast enough to throw the pawls out to grab the shaft.

There is a third possibility that we hadn't even counted upon.....oops sorry, wrong saga.....seriously though, it is also possible but not likely that somehow the gears on the end of the starter motor are not engaging the starter clutch. But since these are meshed when you mount the starter and never disengage unless you remove the starter, it is not very likely and I would not expect it.

[D0wn5h1ft]

This motorcycle uses a starter clutch, versus a starter solenoid like your car does. In either case the whirring sound you hear is the starter motor turning its gear, so the starter motor is doing what it is supposed to do. It just is not engaged with the engine to turn the engine over. Kind of like pulling the belt off of a belt driven motor. In a car and some bikes, there is a solenoid that pulls a gear into place to connect the starter to the engine. Often in those systems, a low voltage or ampacity from the battery will result in the solenoid not getting pulled in.

On these bikes, we have a starter clutch. Basically, the starter motor turns the clutch which throws the engagement pawls and they grab the primary shaft and spin it, spinning the crankshaft through the Hyvo chain. When you release the starter, the pawls withdraw away from the shaft, disengaging the starter from the engine. So, typically, if your hearing a whirring sound, then either the starter clutch itself is worn out, the pawls no longer grab the primary shaft, or your not spinning the clutch fast enough to throw the pawls out to grab the shaft.

There is a third possibility that we hadn't even counted upon.....oops sorry, wrong saga.....seriously though, it is also possible but not likely that somehow the gears on the end of the starter motor are not engaging the starter clutch. But since these are meshed when you mount the starter and never disengage unless you remove the starter, it is not very likely and I would not expect it.

This is the main reason I'm installing a folding kickstart lever. All the gearing is already there for one (unlike later models) and I'd hate to get stuck in the middle of nowhere having to start a campfire under my bike to get the oil fluid enough to not bog down the starter clutch.

[DGXSER]

I don't know exactly how cold of weather you plan on riding in, but I can tell you I have ridden down to about upper 30's lower 40s, and never had an issue with starting the bike. I run 20W-50 year round.

Even when my battery is weak, it has never been an issue of getting the starter clutch to engage, only getting the engine to turn over with enough speed to start it.

Not that I dislike the idea of the kick starter on there. I never really understood why they did not design a folding kick start lever for the XS11 like every other bike of that era that had electric start.

[IanDMacDonald]

Just a heads-up Gabe, using the folding kick lever may not work so well. Looks good, but I believe it hits the footpegs with my 2H9 mod. Not sure about 2H7 pegs. I believe that's why the included kicker splays out so wide. Also, the stroke is not very long like the 750. I have not had success starting the bike with the kicker.

And Don- With temps @ 10° this morning, the starter whirled. I have rode in 20's, and it was okay.

[mikubuilder]

I started my bike yesterday, and it started with no problems whatsoever...did you take starter out for motor rebuild?

[DGXSER]

For S&Gs I spent my lunch break tearing down a spare primary shaft I had laying around to get a good look at the starter clutch, I will put up a separate write up on that.

Now, I can honestly tell you there is nothing to do with oil viscosity and being to thick that will keep that starter clutch from engaging in my opinion. Really, there is not a ton of oil getting in there in the first place. They way it pinches on the shaft, it is going to work cold or hot thick or thin oil. Once it grips, it is turning the engine. Now, I could see thick oil causing the engine to turn slower, but I do not see it keeping the starter clutch from grabbing the shaft.

[D0wn5h1ft]

I started my bike yesterday, and it started with no problems whatsoever...did you take starter out for motor rebuild?

I can honestly tell you there is nothing to do with oil viscosity and being to thick that will keep that starter clutch from engaging in my opinion.

What oil are you running for curiosity sake, Nick?

As far as viscosity is concerned, it doesn't really explain why in warm weather we don't have an issue but in cold weather we do. Multiple users have expressed an issue with rough cold weather starts and running 10w-40 does help. It is significantly colder here than it is in ohio almost year round. It is 29F right now, for instance. I guess the only common factor is that Ian and I both run AGM batteries which do suffer significant increases in esr at reduced temperatures.

[IanDMacDonald]

I have a question: Any way that the kick start lever could cause the whirl? Never had the issue last Winter without the kickstart installed. Quite a coincidence.

[IanDMacDonald]

I just bought a brand-new AGM the other day. Rated @ 350 CCA, tested at over 500.

[D0wn5h1ft]

I have a question: Any way that the kick start lever could cause the whirl? Never had the issue last Winter without the kickstart installed. Quite a coincidence.

That's interesting because right now my kick start gear spring is not connected properly. Last time when I had the side cover off, I didn't put the spring in that slot correctly so the gear doesn't return when you kick it. Maybe you have the same thing going on and that's what is doing it.

Even with a brand new battery it's still not going to perform well at sub-zero temps. It's just a property of AGMs. They are robust but don't play well when it's cold.

Edit: and by sub-zero I mean below freezing...living in the US and having gone to a European high school has me all jacked up on units...

[IanDMacDonald]

No, the spring is in-place.