Cold Weather Start
Club Member
Joined: Oct 2016
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From: Syracuse NY
Road Captain
Joined: Oct 2020
Posts: 518
Likes: 593
From: Central Iowa
Lots of things are working against you when trying to start a very cold engine; the oil is thick causing more drag making the engine crank slower; fuel doesn't vaporize as well making it more difficult to ignite and fully combust; and the battery's ability to supply enough current to the starter drops as well. Anything you can do to minimize any of those problems will help; lower viscosity and/or synthetic oil; a heat source to warm the cylinders, heads, carb, throttle body, etc.; and a healthy well charged and/or warm battery.
Seasoned HDF Member
Joined: Jun 2015
Posts: 10,277
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From: West Central FL
Hook up your battery tender about an hour or so before you head out. When I lived in New England I also aimed a small portable heater at the engine a couple hours in advance.
Seasoned HDF Member
Joined: Dec 2005
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From: poway
Ditto on the Yuasa GYZ32HL, and switch over to 30W or 10-40 weight synthetic oil for cold winter months, and double check your battery and cable connections, including the ground cable to primary case, to make sure it still clean and tight. The reason that I give both, check your oil pressure once the motor does come up heat, and if low with 10-40, then switch over to the 30 weight oil isntead. And synthinc on either,since does not turn to mud when it gets cold like conventional oil.
The next one is battery, and although your may be CCA 400A when worn, will be less when the battery is cold. with the Yuasa GYZ32HL, 500cca warm, but still over 400cca when bone cold. Also, double check your cables, including making sure you have a good connection of the negative cable to the primary as well.
The last one, is keep in mind that the twin cam of that year, used both the crank sensor, and the cam sensor to read spark timing, so double check to make sure that one or both of the sensors is not starting to go out/has a cold problem, and why is so hard to get the bike started.
Bluntly, the engine needs two decent speed revolutions until the ECM is going to throw a spark, and if you are needing to crank the motor (with decent revolution speeds) more then this before it will start, suspect that is one of the sensors (or it connectors) that is having a problem in the first place.
Hence may have a cam sensor that is giving up the ghost (heat related problem that caused the problem in the first place) and needs to be replaced (or can do the cam bypass, if bike is carbed).
Note, later twin cams did way with the cam sensor in later years, since they just ended up having heat problems to cause them to go south quickly in the first place.
So if you solve the slow crank problem with higher CCA battery and thinner oil, and still have to crank the motor more than two revolutions until it fires on the third revolution, suspect problems with the cam sensor (it connection, or the entire sensor isntead).
To add, under the impression that bike is FI, but if carbed, then with choke on, give the throttle a twist or two, to allow the fuel pump in the carb to spray some extra fuel, before you go to start the bike.
The next one is battery, and although your may be CCA 400A when worn, will be less when the battery is cold. with the Yuasa GYZ32HL, 500cca warm, but still over 400cca when bone cold. Also, double check your cables, including making sure you have a good connection of the negative cable to the primary as well.
The last one, is keep in mind that the twin cam of that year, used both the crank sensor, and the cam sensor to read spark timing, so double check to make sure that one or both of the sensors is not starting to go out/has a cold problem, and why is so hard to get the bike started.
Bluntly, the engine needs two decent speed revolutions until the ECM is going to throw a spark, and if you are needing to crank the motor (with decent revolution speeds) more then this before it will start, suspect that is one of the sensors (or it connectors) that is having a problem in the first place.
Hence may have a cam sensor that is giving up the ghost (heat related problem that caused the problem in the first place) and needs to be replaced (or can do the cam bypass, if bike is carbed).
Note, later twin cams did way with the cam sensor in later years, since they just ended up having heat problems to cause them to go south quickly in the first place.
So if you solve the slow crank problem with higher CCA battery and thinner oil, and still have to crank the motor more than two revolutions until it fires on the third revolution, suspect problems with the cam sensor (it connection, or the entire sensor isntead).
To add, under the impression that bike is FI, but if carbed, then with choke on, give the throttle a twist or two, to allow the fuel pump in the carb to spray some extra fuel, before you go to start the bike.
If either the crank sensor or cam sensor fails, the ICM / ECM will throw a dode.. Both are more likely to fail hot not cold.
Where did you get the data on cam sensors failing being the reason for removing them? I'd expect that they removed it for cost when they figured out they could get away with only crank..
Arkansas. I'm a little crazy but I love cold weather. So does the bike, she runs great when it's below freezing.
Seasoned HDF Member
Joined: Mar 2021
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From: backwoods
Air is denser when it is cold, so getting more air when cold.
HDF Community Team
Joined: Jan 2020
Posts: 1,434
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From: Colorado
If bike has alarm system/fob on it, then bike never really goes to full shut down, but sleep mode, and tender on battery will keep it charged as the bike is in sleep mode and draining the battery down with the small sleep mode draw still on it.
If bike is older,and when you shut the key off, no power off the battery going to the bike, then tender on the battery full time can cause the battery to cycle more/cause the battery to go south sooner. So in cases where there is not power draw on the battery with key turned off, then maybe for a day before you put it into storage to bring it up to full charger, and maybe on the tender after a few months for a day as well, then again for a day right before it time to pull the bike out of storage for the season.
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Grand HDF Member
Joined: Mar 2007
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From: Deep in the heart of New Jersey
I have to weigh in on this statement. Starting with my '03 Ultra and other bikes, When you turn the key off there is still power going to the alarm system, and power to keep your radio presets set. Granted not a big draw, but after a month or so of not being run especially if left in the cold, your bike may not start. I to discover'd that using a battery tender monitors the battery's power, and keeps it up to a full charge. I also ride thru the winter and find it really sucks when your ready to go for a ride ,and all you get is a tick when you hit the starter button. I doubt that newer Harley's are any different when it comes to draws on the battery. With all the electronics on the bikes today, it might be more. I know the manual for my '05 and '06 Road king says to run 10w40 wt oil when the temps are 40f or below, to help starting in the cold. I would think it's the same for newer bike's, but checking the manual is the best place to get info like that.,,,,
Seasoned HDF Member
Joined: Mar 2021
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From: backwoods
You don't need to reprogram your radio after replacing a battery, or disconnecting it. Just reset clock.
Last edited by Rounders; Jan 28, 2025 at 05:48 PM.