Has anyone else experienced unsmooth cruising. Almost the same sensation as the old fuel starvation issue. I have plenty of gas, bike is warmed up, and petcock is in the Prime position. Weather was pretty chilly, about 45 degrees. When trying to keep a constant speed, the bike seems to not give steady power. I'm usually in the 4500 - 6000 RPM range. It isn't very bad at all, just annoying. Is it just the nature of our engines in the colder weather? Also, does anyone notice the headlights and gauges dim slightly when applying the brake? I have a brand new battery and has no real problem starting either.
Temperature will affect how the bike runs, but minimally. It should still run smooth when up to operating temps. But it will take a bit longer to get up to those temps. I know I let my bike warm up extra long yesterday (probably 45*F), but it was still sputtering for the first mile or so if I gave it too much throttle. She ran just fine after that though. Note: mine is a 98 with one size larger jets, but it would run about the same with stock jets
Not 100% sure on the headlight dimming, wouldn't surprise me if it dimmed, but only the slightest amount. I know my old 80cc yamaha with a 6V system would dim... especially when I didn't have the battery in it :laugh:
The bike was definitely warmed up. It did it the entire time. It does not putter at all. The best way to describe it is "very slight power variation".
wind can also have the same stumbling effect on our bikes if it hits the bike at the right direction .... there are some others here that may add some to that
I was told to do the rejetting on the coldest day of the year... supposedly when it's cold outside it's very easy to "find" all imperfections in your jetting.
maybe your jetting is the issue? :dunno_white:
It was windy. Also, I was considering rejetting. How much does that usually cost you?
Quote from: ABSOLUTNATI on October 29, 2007, 10:47:44 AM
It was windy. Also, I was considering rejetting. How much does that usually cost you?
$7 to $25+ depending on number of jets you need to buy, and a ton of time trying to get it right. A lot of it depends on your setup. If you've got the stock airbox/filter and pipe, then it's a pretty easy job. If you've got aftermarket stuff then it can be a little more (or a lot more) work.
Yeah, it's stock. I don't really want to do it myself nor do I have the mechanical know-hows. I did just learn how to change my spark plugs and oil myself. How much do shops charge and should I trust them?
Quote from: ABSOLUTNATI on October 29, 2007, 10:02:12 AM
The bike was definitely warmed up. It did it the entire time. It does not putter at all. The best way to describe it is "very slight power variation".
Hmmm. Is the "power variation" something you feel as a variance in the "oomph" of the bike ... in its ability to push you down the road? If so, maybe you've got a plug that's trying to go out on ya. You might want to pop in your spare pair (you do
have a spare pair, right? ;)) and repeat the "test" when you get a chance.
Another possibility is that you're just feeling a kind of "cyclic thrum" of mid-frequency vibration that seems to move from the frame to the engine to the gas tank and around and around again. I first noticed this when I was in the middle of nowhere, cruising at about 5K RPM with no other traffic to distract me. Freaked me out ... but it's normal.
Yet another possibility is an odd, heavier vibration that I feel sometimes feel lower down. It took me a while to realize that this one was caused by the slight out-of-roundness (or density differences) in my tires, and the fact that one wheel rotates at a slightly different rate than the other (because of their different diameters). At cruising speed I can feel the vibrations line up, then oppose each other, then line up again, etc. It's about a 2- or 3-second cycle at around 50 mph.
If you're experiencing something totally different, give us as much detail as you can.
The "cyclic thrum" seems like it might be the most logical. I know the spark plugs are fine. I just changed them 100 miles ago and think that I have noticed the power issue before that. seems to come and go at a constant rate while cruising. "slowly more, than slowly less (three seconds total), slowly more than slowly less (three seconds total).... repeat. Only affects the speed by MAYBE 1-2 mph. Could that mean tires? The tread is fine on the front and rear. Seems to look absolutely fine?!
Quote from: ABSOLUTNATI on October 29, 2007, 11:31:18 AM
Yeah, it's stock. I don't really want to do it myself nor do I have the mechanical know-hows. I did just learn how to change my spark plugs and oil myself. How much do shops charge and should I trust them?
A dealer probably won't do it. Other shops might. I don't really know what it would cost. Should you trust them? Probably not. If you are going to have a shop do it, consider finding one with a dyno and get some print outs before and after. Then post them up here ;) .
Also, someone posted a dyno of a stock GS on this site a while back, and it actually ran rich through most of the rpm range at full throttle. I'd consider just changing the pilot jet to 40's to decrease warm up time. You'll lose a little bit on gas mileage, but it'd probably be worth it for quicker warm ups.
"I'd consider just changing the pilot jet to 40's to decrease warm up time. You'll lose a little bit on gas mileage, but it'd probably be worth it for quicker warm ups."
Yeah, that's all Chinese to me! I have to educate myself a little before I get into that!
Nevermind on the 40 pilots. Your carbs are different than mine, so I don't think 40's will work for you anyway. Look around the Wiki and the modifications page to get an idea about the carbs. They won't be exactly the same as the newer GS's have different carbs, but you'll get an idea.
Or, call some local shops and see what they say.
Quote from: ABSOLUTNATI on October 29, 2007, 12:13:07 PMaffects the speed by MAYBE 1-2 mph. Could that mean tires?
No, that does sound more like an "oomph" issue ... a kind of low-level "surging". The vibrations I described are just that -- vibrations.
Sorry, it FEELS like its affecting the speed. I'll have to double check. It does have a vibration feel to it though, for sure.
kerry
was there not an isue with our vacume operated fuel system about if it is gusty with the wind at the right direction , starves the carbs of fuel???
Quote from: ajaxgs on October 29, 2007, 01:22:22 PM
was there not an isue with our vacume operated fuel system about if it is gusty with the wind at the right direction , starves the carbs of fuel???
Yeah, that brings back some distant memories. The theory being that the wind could affect the pressure (and therefore airflow) at the mouth of the airbox/aftermarket filter?
I don't remember how that particular discussion came out, and I guess I haven't ridden in enough wind lately to have noticed anything. (http://bbburma.net/Smilies/dunno_black.gif)
I live at an elevation of ~4,800 feet, but I don't know how that lower-than-usual atmospheric pressure would compare with a wind gust. My jetting is stock, and the only engine-related mod I've done is to replace the OEM air filter with a K&N in-airbox filter (with restriction ring). Maybe that gives me a slight boost in air intake - enough to counteract the high altitude? I dunno.
I thought that's why a lot of us ride with the petcock on "PRIME". Was that not the temporary solution to that problem? I always ride with it in PRIME on long rides or anything above 30mph.