Choke in cold weather (5c, 40f) on 1981 GS1000G

[Noreg]

I have no experience with chokes, apart from my snow mower (and I don't really care how its engine runs as long as it mows). I have read the manual (2500 rpm max, but also read between 2000 and 3000 somewhere), and 50 seconds.

I start with full choke, and then push it in while putting on my gloves to keep it around 2500. After roughly a minute, I ride off (sometimes with a tiny bit of choke, sometimes I turn it all the way off). It has a tendency to stall if I take the choke off after 50 seconds.

My issue is when I ride off, the engine cuts out at around 4000-4500 rpm (like it slows down rather than speed up when giving throttle). This ONLY happens the first minute or two after leaving. Am I not choking it enough?

After the engine is properly warm after riding for a bit it idles fine.

Im imagining the manual is focused for people with a more sensible climate. The bike itself is warmer usually when I start it (the garage is heated to 18c/64.4f), when trying to start it in the winter, it did not like being started in the garage while the gas in the tank was bellow freezing (for water) temperatures. Should I choke it longer? How long?

Should I just keep the RPM low for the first part of the ride? I sometimes like to take a two minute detour around a neighbourhood to warm it up more (going trough roundabouts in traffic when it stalls at idle is sort of annoying).

I am also curious, how quickly does the bike cool down? Should I use the choke after having a coffe? A hamburger? A smoke? Bear in mind the temperature often is bellow 5c/40f on the mountains and away from the ocean.

Some people seem to keep the rpm much lower than 2500, I find that hard, sometimes when I push the knob it goes too low...

Id like to thank in advance for any answers. I really apprechiate it if you explain your reasoning for doing it a particular way.

[Rob S.]

It sounds like your carbs could use a good cleaning/rebuild.

My manual says to start on full choke, then let it warm up at no more than 2k rpms.

[Noreg]

It sounds like your carbs could use a good cleaning/rebuild.

My manual says to start on full choke, then let it warm up at no more than 2k rpms.

I absolutely agree, I took out the float bowls. They were dirty with rust. So I need to cure the gas tank first.

But how long would you let it warm up at my temperatures? Is 50 seconds enough?

[cowboyup3371]

I will typically put my helmet and glasses on, start the bike, put one glove on, push the choke down halfway, put the other glove on, push the choke in halfway from there, and then start out on the ride. By the time I get about a half mile away it's ready to turn off completely

[Rob S.]

...how long would you let it warm up at my temperatures? Is 50 seconds enough?

You can let it warm up until it holds a nice idle (1100 - 1200 rpms), OR you can ride off very soon on a little bit of choke. Once I'm rolling, I usually shut the choke totally, even if it means I have to be alert on the throttle to keep her from stalling at the first stop sign or two.

[Noreg]

I will typically put my helmet and glasses on, start the bike, put one glove on, push the choke down halfway, put the other glove on, push the choke in halfway from there, and then start out on the ride. By the time I get about a half mile away it's ready to turn off completely

Do you drive it less hard for the first part? or?

[cowboyup3371]

Do you drive it less hard for the first part? or?

Yes as I need to get out of my neighborhood first - that half mile spot puts me on the main road where I can hit 45 miles per hour as long as the school zone lights aren't flashing

[Rob S.]

Do you drive it less hard for the first part? or?

I always go easy at first, because I want to be kind to:

my Suzi
and
my neighbors (in that order ).

I try not to redline cold bikes.

[Noreg]

Yes as I need to get out of my neighborhood first - that half mile spot puts me on the main road where I can hit 45 miles per hour as long as the school zone lights aren't flashing

I guess that makes sense. Little choke, drive off for a bit, take it easy and then after about a click shut the choke off and be ready to let it rip.

[Noreg]

I always go easy at first, because I want to be kind to:

my Suzi
and
my neighbors (in that order ).

I try not to redline cold bikes.

My bike is parked in an industrial area, so no neighbouers. But being nice to the engine is probably a good idea.

[Gorminrider]

My issue is when I ride off, the engine cuts out at around 4000-4500 rpm (like it slows down rather than speed up when giving throttle). This ONLY happens the first minute or two after leaving. Am I not choking it enough?

This exact symptom is Not unusual with carburetors in cold weather. usually called "carburetor icing" but it's not severe as it sounds...

If it goes away as the warmer days arrive, that'd be my guess-a bit of super-chilling of moisture in a small passage maybe roughened by a bit of deposit...something like that. I've got a Honda bike that does it all winter, just at "take off" . It clears up with a bit of throttle applied. In some vehicles it can be more severe and kill the engine at the first 2 or 3 stop signs but yours is not bad.

A real good carbclean might alleviate the symptom and anyways, it's pretty much a requisite of being a "small-engine mechanic" if you are so inclined. otherwise, dump some injector cleaner in the tank and cross your fingers.

Or, You can just wait awhile longer to warm up. 2000rpm is the manual's warmup maximum but the tachometers are probably not exact so just make the engine smooth at the lowest rpm til it's warm.

[Noreg]

This exact symptom is Not unusual with carburetors in cold weather. usually called "carburetor icing" but it's not severe as it sounds...

If it goes away as the warmer days arrive, that'd be my guess-a bit of super-chilling of moisture in a small passage maybe roughened by a bit of deposit...something like that. I've got a Honda bike that does it all winter, just at "take off" . It clears up with a bit of throttle applied. In some vehicles it can be more severe and kill the engine at the first 2 or 3 stop signs but yours is not bad.

A real good carbclean might alleviate the symptom and anyways, it's pretty much a requisite of being a "small-engine mechanic" if you are so inclined. otherwise, dump some injector cleaner in the tank and cross your fingers.

Or, You can just wait awhile longer to warm up. 2000rpm is the manual's warmup maximum but the tachometers are probably not exact so just make the engine smooth at the lowest rpm til it's warm.

What is these warmer days you speak of?

Thankfully the closest stop sign I know of is 140km away and in Sweden (I know of ONE in Norway, and thats 8 hours away). But it seems more prone to stall in the beginning. I generally try to drive my bike the way I drive a bus (stopped wheels = failure).

I know I need to do a proper clean of the carbs are required, but my gas tank is rusty, so I want to fix that first. Throwing a bottle of injection cleaner in the tank I will do, that is cheap and simple. When I fix the tank I want to buy an ultrasound cleaner so I can properly clean all these parts. And replace all the o-rings.

If riding it easy in the beginning isn't bad, Im pretty confident Id be happier to just roll off quicker. I get impatient sitting on the bike.

[Gorminrider]

Oh, don't be impatient. Check your turn signals ,headlights, and brakelight as a routine to waste some time....air-cooled bikes are not mapped-fuel-injected Volvos... I never ride off with any "choke" on, because it's too easy to forget with the first distraction that inevitably appears...a dog, a deer, a lazy robin, a talkative neighbour....

I'm worried about your rusty tank. if it's showing up on the fuel-tap filter get onto that before anything else (except maybe keeping the salt cleaned off)

[rphillips]

Works for me, ride off with choke maybe still 1/4 out. If lucky I remember to push it off after a couple of min., If I forget, at first stop, when I pull the clutch in, eng. rev's. to 2000 or 2500 rpm, then I know to push it completely off. Never been a problem

[Noreg]

Oh, don't be impatient. Check your turn signals ,headlights, and brakelight as a routine to waste some time....air-cooled bikes are not mapped-fuel-injected Volvos... I never ride off with any "choke" on, because it's too easy to forget with the first distraction that inevitably appears...a dog, a deer, a lazy robin, a talkative neighbour....

I'm worried about your rusty tank. if it's showing up on the fuel-tap filter get onto that before anything else (except maybe keeping the salt cleaned off)

I tend to agree on the gas tank issue. I can see tiny amounts of rust in the fule line filter (not sure if it is a filter inside, or just the housing tbf). But in the float bowls there were rust deposits. And there is quite substantial rust at the bottom of the tank.

I just ordered POR-15 motorcycle gas tank sealant kit (three chemicals, one for cleaning chemicals, one to take the rust and some sort of mystical paint you slosh around). So then Ill get the tank sorted. Wonder how you close the petcock holes for the sloshing though. Ive been putting it off because of finacial uncertainties.

Tanks are massively expensive, so I guess its best to stop it from becoming broken.