Cold Mornings Running Rough

[aussiebandit]

I know it's summer in the US, but here in Oz it's the depth of Winter and the 02B12 is hating the cold.

Basically, in the mornings it's anywhere between -5c and +5c, and the B12 rides like a bitch in the morning. It feels and sounds very sick, stalls, almost like it's starved of fuel.

I've tried long warm up, a couple of minutes. But this seems to foul the plugs.  I've tried short, 30 second, warm ups, and that doesn't help.

In the afternoon after work it fires up beautifully, and runs normally.

Any suggestions???? For the record the bike is bog standard and I use regular unleaded.

[Red01]

This may not be much help, but my '01 doesn't foul plugs on my ~2 minute warm-ups in the winter. 

FWIW - my standard winter (actually, 3 season) routine:
1. Start with full choke
2. Adjust choke to keep it in the 2000 RPM area
3. Zip up jacket, attach tail bag, put in ear plugs, don helmet & gloves, repeating #2 as required (usually needs to be turned down 2-3 times in this process).
4. Ride off
5. After ~1/4 mile, turn off choke completely

[CWO4GUNNER]

The only people that believe this have tried it. Because it is underutilized people shy away from running a hotter plug in cold areas and a cooler plug in hotter areas. But it works wonders. I switch out every season between normal in winter and 1 stage cooler in summer on all my bike and its like night and day, but because truisms exist what are you going to do...

[aussiebandit]

This may not be much help, but my '01 doesn't foul plugs on my ~2 minute warm-ups in the winter. 

FWIW - my standard winter (actually, 3 season) routine:
1. Start with full choke
2. Adjust choke to keep it in the 2000 RPM area
3. Zip up jacket, attach tail bag, put in ear plugs, don helmet & gloves, repeating #2 as required (usually needs to be turned down 2-3 times in this process).
4. Ride off
5. After ~1/4 mile, turn off choke completely

That's pretty much my normal routine, but it still doesn't help.  This morning it behaved itself, but then again it was a relatively mild 6c.

[allan4169]

Move out of New South wales and get up to sunny Queensland.  Have you had the primary jets adjusted after having the caps drilled out? Our California bikes have a cap on the primary jets for emissions but it runs very lean and it's bad in the cold weather. So we drill out the caps and richen up the primaries.

[Cruisecontrol]

Try no warm ups at all.

I am in Sydney where it doesn't get real cold and I don't warm the bike up at all.
I gear up, get on, 2/3 choke, start 'er up (no use of the throttle) and ride away. 10 seconds down the road I turn the choke off completely.
I take it easy for a few minutes till things warm up and it is good as gold.

[allan4169]

I live in Los Angeles, actually up in Santa Clarits where in the winter we get into the 30's Far. But I start it on half choke and once it is started I put it at 1/4 or less choke. Any more and it will run rough. But at this setting it idles steadily and then I put on my helmet, gloves, close the grage door and off I go. After two miles I can push the choke to zero. Even in the summer I still use the choke but for a lot less time. Check the choke (enrichener) bar to make sure that it opening and closing correctly. Best of luck.

[aussiebandit]

Move out of New South wales and get up to sunny Queensland.  Have you had the primary jets adjusted after having the caps drilled out? Our California bikes have a cap on the primary jets for emissions but it runs very lean and it's bad in the cold weather. So we drill out the caps and richen up the primaries.

I think I'll give moving to QLD and miss.  My bike may like it, but I can't handle the humidity.

[aussiebandit]

Try no warm ups at all.

I am in Sydney where it doesn't get real cold and I don't warm the bike up at all.
I gear up, get on, 2/3 choke, start 'er up (no use of the throttle) and ride away. 10 seconds down the road I turn the choke off completely.
I take it easy for a few minutes till things warm up and it is good as gold.

I'll give that a try on Monday and see how we go.

[PitterB4]

I'm thinking a half turn out on the a/f screws will cure what ails you.

[aussiebandit]

I don't fancy playing around with the A/F screws as the bike runs fine when the temp is about 5c.

The last few mornings I've tried the "no warm up" routine, and hey presto no problems. I'm just a bit worried about the potential damage that could do to the engine.

[Cruisecontrol]

As long as you don't rev the hell out of it before the oil starts to circulate then there will be no problems at all. I stay under 4 grand for a few minutes and have never had any issues.

[aussiebandit]

As long as you don't rev the hell out of it before the oil starts to circulate then there will be no problems at all. I stay under 4 grand for a few minutes and have never had any issues.

Jeez, if I went over 4 grand in 2nd I'd be braking the 'local area' speed limit, so that's not a problem.

[slow coach]

the best my bike has ever run from a cold start has been with bigger that stock pilots in it,otherwise its always been a 2 or 3 km run before the choke goes in fully.in fact with the bigger pilots in ,it needed virtually no choke and started  perfect,but they needed to be slightly smaller for across the board running and i never got around to the smaller size.
 in fact i will stick my neck out and say that i have read on a site somewhere(don't ask me where) that the stock pilots are to small and the proper size should always have been 20 for the pilots and not 15 from memory.   

Last sunday morning i did a 400km early morn ride and it was 4 degrees then dropped to 3 for the first 200kms ,as confirmed by a thermometer on a cb1300 Honda.When we stopped for coffee i commented that my bike always ran different in the cold,or definatley sounds different and my theory os that the density of the air is so much thicker or heavier on the cold mornings and this alters the volume or ratio of air fuel that the motor is receiving,there by altering the way it will run compared with a summer morning.
Now i'm not a betting man ,but i will bet that if a stock gen 2 1200 bandit is fitted with slightly bigger pilots ,it will start better in the cold,warm up quicker ,and run exactly like a stocker,except with an ants cock more midrange .             cheers    slo coach

[Down Under]

I know it's summer in the US, but here in Oz it's the depth of Winter and the 02B12 is hating the cold.

Basically, in the mornings it's anywhere between -5c and +5c, and the B12 rides like a bitch in the morning. It feels and sounds very sick, stalls, almost like it's starved of fuel.

I've tried long warm up, a couple of minutes. But this seems to foul the plugs.  I've tried short, 30 second, warm ups, and that doesn't help.

In the afternoon after work it fires up beautifully, and runs normally.

Any suggestions???? For the record the bike is bog standard and I use regular unleaded.

Mate, I had a similar problem with my old B1200 which turned out to be carby icing.  I live in a part of Oz with the same range in morning temps.  The bike would start okay etc but after about 10 to 20 mins on the road would start to run rough like it had an air lock in the tank or was running out of juice.  I also noticed a steady decrease in power with the rough running engine.  Would stop in traffic and have to keep revving the engine to stop the bike from stalling.  If I stopped for five to 10 minutes with the engine off and started the bike the engine would run fine until I began riding for sometime again.  It was worse in certain weather conditions but the problem would disappear as the mornings got warmer. 

Running a hotter plug will help if this is the prob.