flat spots everywhere, what do they run like stock?

[intergalactic]

So I have a 1992 GS. Bone stock. Clean air filter, decent plugs, new gas. New stock exhaust. Starts and idles ok. It had old gas in it for 5 months prior to my purchase 2 weeks ago. I have run 3 gallons of new gas and some Seafoam additive thru it. I sprayed  the carbs some brake cleaner.

It runs and I ride it, and it is COLD here. Like 40F. So it has some flat spots. Kind of bucks and makes low speed driveability crappy. Better when warmed up and if it is above 50F out. Is this normal? Above 6K it is fine. Warm with throttle full, it pulls ok from 3000 RPMS up. But transitions and relatively quick throttle modulation from closed to 1/4 ish is pretty rough. Is this normal for a cold older bike? I bought some #40 pilot jets and that is next. But I don't really want to pull the carbs unless I have to. Is this normal? I am used to driving a direct injected diesel car, so I am not familiar with a carburetted bike.

[fred]

You sprayed brake cleaner into your carbs? While they were on the bike? That's not good. I'm pretty sure that stuff eats rubber, and there are a fair number of critical parts of your carbs made from rubber and plastic. You're not even supposed to use carb cleaner on the rubber parts of your carb, you're supposed to take the carb apart then only use the carb cleaner on the metal bits. Not to say this is the only problem you have, but if you just dissolve your diaphragms or some o-rings, you certainly didn't make it better... Also, what does the bottom of your tank look like? Shine a flashlight in there to make sure it isn't full of rust. If it is full of rust, you need to take care of that first because every time you clean the carbs, they will just clog up with rust flakes again.

[commuterdude]

First off, the carbs are easy to work on.   Get a manual and pull your carbs!  Rejet 40 pilots 125 mains.   Get a Honda fuel petcock for the frame (check the wiki), and run an inline filter between it and your carbs.   Flat spots will disappear!

[intergalactic]

Well, I only have new pilots, so that will have to do for now. Maybe I'll throw another washer under the mains for now. I have a fuel filter to install too.

Sounds like all this isn't normal.

[bill14224]

I live in Buffalo.  What you're describing is ABSOLUTELY normal.  It's not a problem.  The only problem is you're mental like me so you're riding in 40 degree weather. 

Ignore southerners who give advice on this topic, not paying any attention to where you live.  Happens a lot for some reason.  They'll make you think there's a problem when there isn't.

I would like to make this proclamation:

TO ALL OF YOU WHO LIVE SOUTH OF MARYLAND.. WHEN ANYONE ASKS ABOUT COLD STARTING, CHOKE, OR THE LIKE... SHUT UP!!!  YOU ARE A SUMO WRESTLER BEING ASKED ABOUT BALLET!!'

Fred gave the only useful piece of advice.  DON'T SPRAY BRAKE CLEANER IN YOUR CARBS.  Exactly how did you mix-up your brakes with your carbs, anyway?

[Paulcet]

Heh, I rode to work last week at 40*F.  I rode all winter, coldest was 23*F.  I let the bike warm up for at least 5 minutes on full choke.  Go to 1/2 choke and ride.  Slight stumble under 3K until I get out of the subdivision.  Choke off and life is good!  (and cold, but still good)

And I live WAAAYYY south of the Mason-Dixon line. 

[bill14224]

Paul, what you're saying makes sense.  In your case I'll make an exception, but when it's 40 and 23 where you live it's 30 and 15 where we live, and we have to keep our chokes on all the way to work.  I've heard several ask about this and certain southerners automatically spout that there's a problem with the bike, and they're just plain wrong.

45 mpg?  Really?  Time for a rebuild unless you ride the brakes.  You're 15 mpg short.

[commuterdude]

My bike runs smooth in the cold.  It's a '92 and exhibited the same symptoms as posted,  so I recommended the fixes that worked for me.   Your mileage may very.  BTW it does get cold here in the winter, certainly down into the 30's and 40's from Dec-Mar.  

[bill14224]

Commuterdude, why add confusion by speaking half the truth?  You should have said "My bike runs smooth in the cold as long as I keep the choke on 1/4 after idling for 5 minutes."

That way there's no room for misunderstanding.

There is also a difference between 30 and dry and 30 and humid.  When the humidity's up it'll keep the engine cold all the way to work.  I'm an expert at cold and humid.  I live in the armpit of the East!

When it's around freezing and humidity is above 50% the GS doesn't make enough heat to ever reach full temperature, requiring a little choke as long as you're riding.

[commuterdude]

I would have, if that were the case, but it's not.   On New Years Eve I rode the bike 2 miles to a friends for fireworks, it was 15 degrees out, and no choke necessary after the initial warm up.   The wiki has some good links to jetting and differing symptoms of rich/lean.   Good luck with the bike. 

[bill14224]

My bike runs fine when it's above 40, and even when it's colder it starts immediately with some choke.  NY and Mass. are colder than Dixie.  Look at a map.  I don't know what else to say.  Should I jet richer so I can be too rich all summer?  I think not.

[intergalactic]

Well, it was 40F and about 80-90% humidity yesterday.That was part of it, I bet. Well it runs better after some brake cleaner, sprayed  *while running* down the throttle bodies. It seems to run better. I am going to just ride today, then try a #40 pilot jet.

[joshr08]

ok well while telling yourself it ran better while spraying brake clean into the carbs while running thats because you were adding a flameable spray into the bike and it was raising the rpms.  good luck with not blowing yourself or bike up.

[intergalactic]

ok well while telling yourself it ran better while spraying brake clean into the carbs while running thats because you were adding a flameable spray into the bike and it was raising the rpms.  good luck with not blowing yourself or bike up.

Nope. Chlorinated brake cleaner. Non flammable, so too much would stall it. It runs better now after I used it. Maybe my carbs will fall apart later. But I doubt it. Anyways, info from someone from NY is nice. I was wondering if I was icing up the carbs, actually.

[ohgood]

My bike runs fine when it's above 40, and even when it's colder it starts immediately with some choke.  NY and Mass. are colder than Dixie.  Look at a map.  I don't know what else to say.  Should I jet richer so I can be too rich all summer?  I think not.

re jetting has been covered thoroughly. it helps on cold mornings, yes. as far as no one below whatever marker knowing what cold is... uhm, ok.

once rejetted and adjusted the bike should ride nicely after it's warm, and no, it will not require choke during the entire ride. maybe you're lean. that's my guess.

[intergalactic]

Anyone run #40 pilots and stock (122.5) mains (and like it)? I'd rather not tear the carbs out twice as all I have are pilots handy.  Like I said, the bike is bone stock. North of Boston, 200 feet above sea level. Highest I go is probably 800 feet above sea level.

[fred]

I live in Buffalo.  What you're describing is ABSOLUTELY normal.  It's not a problem.  The only problem is you're mental like me so you're riding in 40 degree weather. 

Ignore southerners who give advice on this topic, not paying any attention to where you live.  Happens a lot for some reason.  They'll make you think there's a problem when there isn't.

I would like to make this proclamation:

TO ALL OF YOU WHO LIVE SOUTH OF MARYLAND.. WHEN ANYONE ASKS ABOUT COLD STARTING, CHOKE, OR THE LIKE... SHUT UP!!!  YOU ARE A SUMO WRESTLER BEING ASKED ABOUT BALLET!!'

Fred gave the only useful piece of advice.  DON'T SPRAY BRAKE CLEANER IN YOUR CARBS.  Exactly how did you mix-up your brakes with your carbs, anyway?

Hey now, it is the desert out here. Just because it is warm in the day time doesn't mean it won't be cold at night. I've ridden plenty of days where it is over 90 on my way to work then in the 40's on my way home. Just because it doesn't snow here doesn't mean it doesn't go into the 20's and 30's, it is just a dry cold. When I lived in San Diego I remember seeing the weather report for an area to the eastern edge of the county on TV where the daily high was 90 and the low was 19. If you're more than a few miles away from the coast, as soon as the sun goes down the temperature drops really really fast. Also if you are traveling west to east from the coast, the temperature gradient gets higher than 1 degree per mile. Just riding from the coast to my place (still in the city of LA) can cause you to experience a temperature difference of 17 degrees or more. You guys out east have enough humidity that the temperature is pretty stable all day long. Around here you could very easily go on a ride and experience a 50 degree temperature drop. If I left my house right now where it is 70 degrees out, I could be in Big Bear in under a couple of hours where it is 25. It makes selecting gear to go riding in harder because you need stuff that can be your hot weather and cold weather gear on the same day. When you're out riding in 80 degree weather with 98% humidity, you can be confident that it will the that temperature for weeks on end.

One more point, since we don't have seasons out here, we get way more riding time in. There is not a single day around here that you can't ride a bike, which means us southerners from California have a whole lot more days of the year to get out there and break something on our bikes, although we don't know anything about battery tenders or winter storage...

[Big Shot]

Since we don't have seasons out here, we get way more riding time in. There is not a single day around here that you can't ride a bike...

I hate you :p - Bob!

[fred]

Since we don't have seasons out here, we get way more riding time in. There is not a single day around here that you can't ride a bike...

I hate you :p - Bob!

Yeah, we can also lane split legally and there is no bike inspection, so you can get away with whatever modifications you want as long as they won't actively annoy cops... It is a pretty cool place to ride a bike overall and with the traffic around here, I'm surprised more people don't do it...

[commuterdude]

Anyone run #40 pilots and stock (122.5) mains (and like it)? I'd rather not tear the carbs out twice as all I have are pilots handy.  Like I said, the bike is bone stock. North of Boston, 200 feet above sea level. Highest I go is probably 800 feet above sea level.

I ran that for a while, was slightly on the lean side but not terribly so when doing a plug chop at 8K....when it's on the mains it is just the stock setting.