Folks, it looks to me like 50% of the problems reported in this forum are due to people screwing around with the carburetors when they know not what they do.
I learned a long time ago that carburetors and amateur mechanics are a deadly combination. That's why I quit *&*ing with them. It seems like a simple thing, but in the long run, the factory has worked pretty dern hard to get them to work reliably given the various demands placed by temperature, relative pressure, speed, acceleration, airbox resistance, pipe and muffler performance, etc.
Then somebody comes along as says, "Hey-I can make it better than Suzuki!" (who has been building and racing bikes since the 1940s or 50s). What people don't think about is how completely dependent everything is on everything else.
I have a used 2001 GS500 that runs perfectly. It takes about 2 minutes on choke, plus about two blocks down the road, to smooth out and run right. Then it never falters, never misses, accelerates just fine all through the power band, and gets 75 miles per gallon of gasoline. Which cancels out at least 1/4 of a Hummer.
I know, I know, I used to like to screw around with carbs and other stuff too. What I learned: leave the carbs alone, unless you like to work all day trying to solve all the other problems you just created.
The same goes for older british cars with twin SU carbs.
Yeah... that's definitely true on a well mantained bike, but... a lot of our bikes were abused or left sitting for months or years and the carbs are gummed up and gross. As far as modifying stuff goes.. well. That's just how it is. Some people can't leave well enough alone, myself included. You want to get a little more power out of the bike, you're going to have to mess with the carbs. That said, if you just read and listen and do what Srinath and the rest of the board tells you, it's a snap. I'm definitely an amateur but just today on the ride back from class I was thinking... man, this thing couldn't possibly run any smoother... :dunno: To each their own I suppose.
trey
Leave it alone, HA!
I can always make it better.
Adjusting the GS carbs are nothing......try tuning a 2-stroke race bike all day long. Its jetting requirements change as fast as the weather, no matter how slight.
So this means that if my bike runs really lean and hot down in the valley, it should get perfect carburetion up in the mountains, because with elevation there is less atmospheric pressure, and thus less oxygen, and this is where I spend most of my time anyway.
One thing to notice is that most peoples' mods are taking the carbs back to what they were originally set up like. Originally before pollution laws forced the manufacturers to lean out the engine to pass emissions tests Suzuki selected a set up that made the engine run nice, that is what people are trying to regain.
Quote from: scratchSo this means that if my bike runs really lean and hot down in the valley, it should get perfect carburetion up in the mountains, because with elevation there is less atmospheric pressure, and thus less oxygen, and this is where I spend most of my time anyway.
That's my story too - and I'm sticking to it!
Elevation: 4,850
Carb Cleanings: 1 or 2
Rejets: 0
Mixture Screw changes: 0
I learn alot from making mistakes, and on the GS the penalties are light and few. I wouldn't want to pay for someone to screw up my carbs if i ever needed any work done. I'll gladly put up with my current shortcomings as a mechanic if i can get better. Suzuki knows what they're doing, but they have a bottom line. :cheers:
:lol: Yea the factory did a great job on them, one more jet size and they would all be burning down
Quote from: Mountaineergets 75 miles per gallon of gasoline.
That makes me want to put the stock pilot jets back in...but, leave everything else alone. Maybe I'll put the stock mains back in, too...aw, heck, might as well as put everything back to stock.
QuoteFolks, it looks to me like 50% of the problems reported in this forum are due to people screwing around with the carburetors when they know not what they do.
I get your overall point but I don't think your statement is fair. It is clear that lots of compromises were made by Suzuki when producing the GS500. The pilot jets were clearly an easy way of meeting emissions while sacrificing cold performance.
Many of us picked up neglected bikes with gummed up carbs and what not. I didn't buy a $800 bike just to haul it to the dealer to pay $300 bucks for a carb rebuild! When I had my carbs open I decided to spend the $10 for new pilots and I have been very happy. My commute puts me immediately in stop and go traffic and not having to screw with the choke is very nice.
Otherwise I'm running a stock bike.
Others want to squeeze out a few more HP for track or street. More power to 'em so to speak :lol:
Most of us here are cheapskates and tweakers in one way or another.
I love taking things apart and messing with them. If you 'break' them you learn. It's much cheaper to do-it-yourself, you can pay $50 an hour for the mechanic to just LOOK at your bike. i would rather get my hands dirty, use the tools, and learn for myself. With the help of the interent and especially this forum, if we get stuck, there is ALWAYS an answer.
Matt
If I wanted a bike I didn't want to f*ck with I'd get a fuel injected Honda, I mean, a generator (no offense Pantablo).
The only problem with letting an experienced mechanic work on your carbs is that they're always hurrying to get to the next job. They'd be just as or more likely to forget something important as an amateur would.
I experienced that firsthand when I let a mechanic put a clutch in my truck. When I got it back the exhaust kept getting louder and louder. It turned out he forgot to retighten the exhaust flange bolts. When you work on your own stuff you can take your time and make sure it's right.
These carbs are not that complicated. Just ask an experienced person how to jet it and you can take care of the rest. I just completely cleaned, rebuilt, and rejetted my carbs. The bike now runs absolutely perfectly after I fixed the two fuel lines I screwed up. :lol:
Derek
carbs are fun,i bought my gs new in 00 and i just rejeted with a pipe. it runs better than stock,i also keep it show room clean my bike is going to last me a long time. i have in the past bought vary used bikes that i couldent fix the carbs but i learned from working on crappy bikes. just keep doing what your doing and years from now you will joke about the stuf you did. see ya.
Quote from: DerekNCThe only problem with letting an experienced mechanic work on your carbs is that they're always hurrying to get to the next job. They'd be just as or more likely to forget something important as an amateur would.
Derek
Like forgetting to bolt on the brakes in my gs. I got it back home, test driving it, comming up to a stop sign and my brakes fall off. Talk about a scary expierience. I could guarantee you I would never forget to bolt my brakes on.
The next morning they called and told me to bring the bike in right away b/c they beleive their mechanic forgot to bolt on my brakes. I said NO shaZam! and I'll be in there asap.
Needless to say they gave me a bunch of free stuff and they are lucky I didn't sue their asses off.
Matt
Yea the factory set the carbs up perfectly ... and sent all those bikes to canada :lol:
All we do is copy canadian bikes and we're good. Where do yout think I got the idea to fit 40 pilots and 125 mains ...
Cool.
Srinath.
Quote from: notoriouskeefQuote from: DerekNCThe only problem with letting an experienced mechanic work on your carbs is that they're always hurrying to get to the next job. They'd be just as or more likely to forget something important as an amateur would.
Derek
Like forgetting to bolt on the brakes in my gs. I got it back home, test driving it, comming up to a stop sign and my brakes fall off. Talk about a scary expierience. I could guarantee you I would never forget to bolt my brakes on.
The next morning they called and told me to bring the bike in right away b/c they beleive their mechanic forgot to bolt on my brakes. I said NO shaZam! and I'll be in there asap.
Needless to say they gave me a bunch of free stuff and they are lucky I didn't sue their asses off.
Matt
on the same note... buy decent parts... the guy i bought my gs from (coworker) changed his clutch in his car and used a cheapo pep boys one or something... bottom like is after dropping the tranny and replacing the clutch (8hrs of labor) the new throwout bearing is bad..... had to tear it all apart again...
Larry said,
"It is clear that lots of compromises were made by Suzuki when producing the GS500. The pilot jets were clearly an easy way of meeting emissions while sacrificing cold performance."
That doesn't sound like a very big compromise. When the bike is cold, it shouldn't be expected to perform like one that is warmed up.
It seems to me that minimum emmissions indicates a clean burn. More emmissions point to incomplete combustion and wasted fuel. Where is the performance in that? I understand why a choke is needed on a cold start. Cars nowadays have a lot of technology to get the thing to run fine when cold. That would be impractical on a bike. Once the bike is warmed up, then what you want is a clean burning engine that develops maximum power. If you move the fuel/air mixture off of that standard, how is it that performance improves?
Quote from: KerryQuote from: scratchSo this means that if my bike runs really lean and hot down in the valley, it should get perfect carburetion up in the mountains, because with elevation there is less atmospheric pressure, and thus less oxygen, and this is where I spend most of my time anyway.
That's my story too - and I'm sticking to it!
Elevation: 4,850
Carb Cleanings: 1 or 2
Rejets: 0
Mixture Screw changes: 0
That's great for you guys, but I live at
Elevation: 9
:lol:
Quote from: MountaineerLarry said,
"It is clear that lots of compromises were made by Suzuki when producing the GS500. The pilot jets were clearly an easy way of meeting emissions while sacrificing cold performance."
That doesn't sound like a very big compromise. When the bike is cold, it shouldn't be expected to perform like one that is warmed up.
It seems to me that minimum emmissions indicates a clean burn. More emmissions point to incomplete combustion and wasted fuel. Where is the performance in that? I understand why a choke is needed on a cold start. Cars nowadays have a lot of technology to get the thing to run fine when cold. That would be impractical on a bike. Once the bike is warmed up, then what you want is a clean burning engine that develops maximum power. If you move the fuel/air mixture off of that standard, how is it that performance improves?
Minimum emmissions indicates not clean burn, it indicates unburnt air (oxygen)... now even a richer mix has un burnt air ... but less of it. You ahve fully burnt hydro carbons, partially burnt HC's and un burnt HC's as well as un burnt air in all IC engines. The richer the mix ... the more the first 3 and less the last one. The more O2 you have ... meaning leaner mix = hotter motor = less life in air cooled motor. Water cooled's however react much differently ... you miss by more than 1-2 jet sizes and it will run like shaZam!. Example ... 1 size larger pilot in a GS (42.5) = barely noticeable, do that on an eli 1000 40 from the stock 38 ... and nightmare. ... not just off idle where you'd expect it ... all over. Miss the thing on the lean side and similar effect. water cooleds dont adjust their temperature that well, air cooled bike will cover anyhting with less or more heat ... You really want to jet it toi being the richest possible and still run well under all weather conditions. That will be the coolest running motor that still comes up to temp and lets oil and everyhting work well. In any case, jetting with a stock setup will pretty much do that for you. No real power from 1 size jetting. Its like that 1/2 mm overbore ... no chance it will make more horses ... Its just to start afresh and erase the wear on it, same thing with jetting. You might have altitude working for you as does kerry so y'all feel you are spot on. The rest of us ... well we want to be Canadian ...
Cool.
Srinath.
:lol:
I really wish I could find a decent temp gauge to put on the bike. I rode a GS 400 for 27 years including a lot of time going real slow, up hill, on forest dirt roads. The thing was stock all around (rusty as shaZam!) and although I did occasionally fiddle with the mixture screws, it was always to get the best smooth running at idle. The engine was nearly identical to the current GS500. The old bike got about 50mpg. It never exhibited overheating, and I never saw any evidence on the plugs. Sometimes it would get a bit hot to the touch, but it never stumbled or locked up.
With the 2001 GS500, I'm getting about the same deal but the plugs are very light-not white. I just did the 7500 mile plug replacement, and the old ones looked good. Steady 75+ mpg.
If the old GS could rack up 27,000 miles I guess I'll take my chances on the new, much-improved version with the factory tune. But I still wish I could find a good temp gauge. Any ideas on that?