What does your bike Idle at?

I just recently carb synced and colortuned my bike and the lowest steady idle I can get is 1500 rpms. I guess this isn't bad, but I really like the sound of a bike that idles strong and low (like 1000 rpms)--who doesn't?. I suppose I could enrich the idle mixture, but I don't want mpg to go up either. Oh well, I guess i'm just picky like that.

Anyways, while I was tuning the bike up, I started to wonder what idle rpms everyone gets, and also what is average. So let me know, I'm curious.

 

Mine idles at 1025 to 1050, The spec. is 1050.
1500 is to high.

 

I think mine is just under 1100 when fully warmed up.

 

1050 is happy land for my beast.

 

mine sits around 800 or so, problem is when at that rpm the engine will die. Another couple of weeks or so and the carbs will be getting cleaned and readjusted, so I should be at or near the specs.

 

Mine sits around 1100 when warm. Setting it to 2000 is a good way to get rid of that primary chain rattle though. :wink:

 

wow...I guess I was off on the options for the poll. I should have made it more specific and lower, or maybe I'm the only idiot crusin around with a high idle.

I was also wondering about oil viscosity and the effect it has on idling, if any. The weather was cold here in Connecticut for a while so I've had 10w30 oil in it. But a couple of days ago it it got nice and warm (~60) and that's when the idle was set. But today it cooled back down to about 40 and I checked the bike and it was idling lower (this could also just be because I didn't warm it up completely, So it's not the most accurate gauge.) I plan on changing the oil anyway to 20w-40 or 20w-50 in the near future. But what do you guys think?

Also, Let me know of any tips that will help me lower the idle.

Thanks

 

Someone has to ask, not trying to be smart but you do know there's a idle adjustment screw.
Located between #2 and #3 carbs on the back side. Counterclockwise to lower the idle.
I'm realy not trying to offend anyone, just don't know your level of mechanical ability.

 

A resonable question Rich, I assumed a basic understanding and I'm willing to acknowledge I may have assumed incorrectly. There is no harm in asking to determine competency, it is a basic questioning technique for teaching. Good on you for recognizing this. I would be curious to to find out yoyoming1001's abilities. Perhaps this should serve as a lesson about plumbing the depth of ability before offering up the advice. Yoyoming, are you familiar with the idle adjustment thumbscrew Rich mentioned?

 

A very reasonable question indeed. I am familar with the main idle screw. I just can't get it lower than 1500 rpms because the bike faulters and stalls. If i'm correct, the main screw slightly opens or slightly closes the throttle butterfly valves, as if the handle throttle was being finely turned and held steady(this is the way I think of it at least). Oh yeah! I'm the man! jk

As far as my mechanic abilities, they are minimal, but i'm not totally incompetent. I think I have a fairly solid understanding motorcycles, in general--what is supposed to happen and also where everything is. My diagnosing abilities are poor though, and that is why I ask stupid questions sometimes, because I grasp at straws. I am a newbie though and I learn mostly through you guys.

 

The only stupid question is the one you don't ask, There are no stupid questions.
I'm new to the sync process myself. Are you trying to get the carb sticks to read even or are you trying to get the highest reading? I'm not sure I'm right but if your trying to get the highest reading, then your actually opening the plates more which would account for higher idle. How high the gauges rise doesn't matter, just that they read as close to the same thing as possible. Maybe try re-sycning and try to get the readings lower but even. Hope this makes sense. Someone correct me if I'm wrong.
Wouldn't the vacuum rise as the plates open, the further open the plate the higher the idle?

You've mentioned the sync and colortune. Have you looked at the carbs themselves for dirt and grud in the bowls. Might be time for a carb cleaning.

 

You are correct Yoyoming1001, the screw does open the entire bank's valves. The book specifically points out that no specifications are given for how much vacuum should be present so your guess is as good as anyone elses. Give Rich's advice a shot, you can always change it back (provided your doing the sync yourself). As for your question Rich, check out Bernoulli's principle. It states that "when a fluid flowing through a tube reaches a constriction or narrowing of the tube, the speed of the fluid passing through the constriction is increased and its pressure decreased". This means that as you open the valve, vacuum decreases (vacuum being the opposite of pressure) but I don't believe that translates into a higher idle as much as a faster RPM although that is exactly what the idle screw does. I'm sounding silly at this point but there it is. Cheers!

 

make sure you have play in the throttle cable. if you don't the idle will change when you turn the handle bars.

 

Good advice all.

When I first synced, I adjusted 1 to 2, 3 to 4, and then them both together like you're supposed to. I did that at first, but soon I became frustrated and just began turning things left and right to get it to balance out, I think I wanted it to be too perfect. So In the end I very well might have gotten a higher reading. I'll give it a go again and try for a lower reading. It's definitely worth a shot.

And monster, that is a very good point about the freeplay. I could have used that advice about a week ago. I adjusted the freeplay in the winter, when the bike wasn't running (i still don't know what possessed me to do that). Anyway, I adjusted it in the wrong direction, making the line overly tight. So when I started her up, the bike would jump to 5000 rpms and just stay there. Well, me with my poor diagnosing abilities, thought that there was a float stuck letting gas in, or some other obscure problem. Anyways, to make a long story short, I was just about to take the carbs off and have a look when I decided to just fool around a bit while sitting on the bike. Immediately I figured out that my throttle cable was so tightly adjusted that when I turned the handlebars, the bike would rev up as if I was turning the throttle.

I was humbled that day and I learned a valuable lesson that I often overlook, which is to always look at the simplest explanation first, before getting fancy and overly thinking the problem.

 

My current bike idles at @ 1500 when hot but my old 1982 Maxim 750 would idle right at 1000 after I sync-ed the carbs, something I'm gonna do to this 550. Carb syncing the carbs makes a LOT of difference on a bike (provided you have good carbs to begin with.