Alright, this is my first bike and my first mechanical project ever. Quick rundown on what's going on with it:
When I first got it I could feel it hesitating a lot and it would occasionally stall. Read up and it seemed like this was likely due to dirty carbs. Bought two carb rebuild kits, and changed all the O-rings, the float needle, and jets. Cleaned the carbs. Bike has a V+H exhaust mod and I read that 127.5 was the right size for that exhaust.
While I was putting the carbs back on I saw that I had some dryrot in the fuel lines. At this point I also checked the tank for rust, and indeed it was fairly rusty. Bought a tank sealer kit (POR-15) and de-rusted/sealed the tank. Also bought some tygon tubing and replaced all the fuel lines and put a filter in-line right before the carbs.
Bike starts right away, but idles very high with the airbox on. After a minute or so running, it stalls out, and I can observe some smoke coming out of the airbox vent at the bottom, and one of the inlets off the airbox is wet with gas (RE: just one, could this be due to the lean of the bike? the inlet that is wet is the one towards the direction of the bike's lean?)
With the airbox off it idles at about 2k or so.
I'm thinking potential vacuum leak? Is the airbox simple not on correctly? Do I need to adjust my float height?
I'm going to take a few pictures and maybe a video and be back. I have the day off, and I'm motivated to get this thing on the road so I can enjoy the last month or two of riding season!
A million thanks to anyone who can help this idiot out. I consider myself fairly sharp, but for whatever reason it DOES NOT translate to mechanical aptitude. Got no cash for professional repairs, so this will have to be DIY. :embarrassed:
Airbox off = better running.
Airbox on = less air and she no run.
Have you checked the air filter? You could just remove the air filter = same as removing entire air box.
Bet your air filter is all clogged up so you are very rich due to lack of air.
Air filter is the only thing in the air box that restricts air flow.
127.5 is if you have pipe and air box K&N. If stock air filter it has to be a 125.
Cool.
Buddha.
Quote from: adidasguy on October 07, 2011, 11:11:24 AM
Airbox off = better running.
Airbox on = less air and she no run.
Have you checked the air filter? You could just remove the air filter = same as removing entire air box.
Bet your air filter is all clogged up so you are very rich due to lack of air.
Air filter is the only thing in the air box that restricts air flow.
Air filter is new and very clean, I don't think it's clogged up, but I hear what you're saying. I am wondering also if somehow the airbox is kinking the fuel lines when it's installed? Would that make sense?
Also note, with airbox off if I twist the throttle the bike stalls out. I assume this is normal but I don't know why.
Quote from: The Buddha on October 07, 2011, 11:14:38 AM
127.5 is if you have pipe and air box K&N. If stock air filter it has to be a 125.
Cool.
Buddha.
Will this make a difference in terms of whether or not the bike is ridable or will this just improve the smoothness?
From what I've seen in replacing fuel lines, they are really tight between the frame and the air box. A real PITA to get them routed and not pinched. YES is the correct answer to your question. Check them when you put the air box back on. Since the air box is only a holder for the air filter, if you have the problem with the air filter removed then you probably did pinch the fuel lines. There are 2 fuel lines from the tank, try on ON and on RES and on PRIME. If only one line is pinched, one of the 3 settings will work.
Don't forget to check the routing of the vacuum line to the fuel petcock. If that gets pinched, it will only work on PRIME.
Remember you need PRIME for a little free-flow of fuel to refill the carbs after they are drained. You can run on PRIME but don't leave it that way since the fuel is not shut off and can overfill the carbs or drip if you have a leak somewhere.
Quote from: elementxero on October 07, 2011, 11:28:16 AM
Quote from: The Buddha on October 07, 2011, 11:14:38 AM
127.5 is if you have pipe and air box K&N. If stock air filter it has to be a 125.
Cool.
Buddha.
Will this make a difference in terms of whether or not the bike is ridable or will this just improve the smoothness?
It should start and be fine just maybe a wee bit soft up high.
Cool.
Buddha.
Did you open the petcock in the tank ?
Cool.
Buddha.
Quote from: The Buddha on October 07, 2011, 11:35:37 AM
Did you open the petcock in the tank ?
Cool.
Buddha.
Yes.
Currently charging my battery back up because I drained it tinkering this morning. I will look at those fuel lines first.
Hmmm, install a fuel filter and run out of fuel when revving. Solution = remove fuel filter.
Unless you have a motorcycle specific filter you are likely to have fuel flow problems. Even with s bike filter you can still have issues.
You may have other issues, but as long as their is a filter you could be chasing your tail. Remove the filter to remove a variable from your trouble shooting.
Michael
Per the above suggestion I took the fuel filter out of line.
This is now how the bike starts and idles with no airbox:
http://www.youtube.com/watch?v=gknBb-JSAxE
You're idling wihtout airbox but stalling with it ? dude then your float is high, 2-3 mm too high will do it.
Oddly @ speed a 1/2 mm high float wont affect anything ... I rode my vulcan 750 fine across 1/2 the east bay and near oakland I felt a bit soggy power, I rode over the bay bridge and as soon as I got to my exit light it stalled.
That's a stuck open float for ya.
Fixed it that evening with this chick from work watching me as I shook the bike like a madman, then pulled the spark plugs out, cranked a few times and let gas fly ... put the plugs back in and started it.
Cool.
Buddha.
Quote from: The Buddha on October 07, 2011, 01:58:01 PM
You're idling wihtout airbox but stalling with it ? dude then your float is high, 2-3 mm too high will do it.
Oddly @ speed a 1/2 mm high float wont affect anything ... I rode my vulcan 750 fine across 1/2 the east bay and near oakland I felt a bit soggy power, I rode over the bay bridge and as soon as I got to my exit light it stalled.
That's a stuck open float for ya.
Fixed it that evening with this chick from work watching me as I shook the bike like a madman, then pulled the spark plugs out, cranked a few times and let gas fly ... put the plugs back in and started it.
Cool.
Buddha.
did you watch the vid I just posted? does that seem like a float issue to you?
I am not looking forward to ripping out the carbs again but if you think that's the deal I will.
Quote from: elementxero on October 07, 2011, 02:01:15 PM
Quote from: The Buddha on October 07, 2011, 01:58:01 PM
You're idling wihtout airbox but stalling with it ? dude then your float is high, 2-3 mm too high will do it.
Oddly @ speed a 1/2 mm high float wont affect anything ... I rode my vulcan 750 fine across 1/2 the east bay and near oakland I felt a bit soggy power, I rode over the bay bridge and as soon as I got to my exit light it stalled.
That's a stuck open float for ya.
Fixed it that evening with this chick from work watching me as I shook the bike like a madman, then pulled the spark plugs out, cranked a few times and let gas fly ... put the plugs back in and started it.
Cool.
Buddha.
did you watch the vid I just posted? does that seem like a float issue to you?
I am not looking forward to ripping out the carbs again but if you think that's the deal I will.
I did not ... sorry cannot do it @ work, and dont have time after I get home, which wont be till 9pm today.
Anyway U tube method it dude, then tear into it if its too high.
Cool.
Buddha.
hey budda do you know if there is anyway to adjust your float heigh right the first time instead of playing the guessing game and do the clear tube method?
also can i instal a k&n lunch box air filter on stock jets (125.. or whatever it is) ?? or will my bike have to much air going to it, witch will make it hard to start???
P.s. sorry for hijacking your thread man, you brought up a lot of question for me lol..
QuoteBike starts right away, but idles very high with the airbox on.
With the airbox off it idles at about 2k or so
Should that have been opposite? Idles high without airbox and low with? Also, when you say airbox you mean filter right? That is, with air passing through a filter before entering the carbs.
Ok. So as it stands now you have a bike with new fuel lines and thus no visible reason fuel should run low - apart from gas tank vapor lock due to clogged tank breathers. And in this way, without the restricting filter the bike revs high without choke?
So, now introduce the air box again and see, then the air filter and see. One thing at a time. Also, put on center stand to rule out sideways tilt.
Michael
To me, it seems you are running rich.
Guessing float level is high. Or choke is stuck on. Or something else ehh.
That big loop in the fuel line between frame petcock and carb looks weird... but i guess it should work.
Revs high at idle speed with no air filter, but idles low with air filter right? == rich to me.
How does it ride? What i mean is... does it have power when you ride it, or is it low on power.
How do your plugs look?
Does your idle respond to changes in the idle speed adjustment (basically can you adjust the idle to a regular rpm like about 1200-1500 rpm with the filter off?)?
Try removing choke cable, and manually moving it to closed and holding it there and then start it and see how it does....
Try turning off the frame &/or tank petcock, drain 'some' of the fuel out of the carbs, see if it runs better (or just do the daggone u-tube test).
note: if you replace the carb float screws with allen head bolts, then you can remove float bowl to adjust float height without removing tank/airbox/carb/etc.
Good luck.
if it was my bike i would have fuel line coming up from bottem into carb to prevent airlock in loop ,never over the top.
Quote from: elementxero on October 07, 2011, 01:18:32 PM
Per the above suggestion I took the fuel filter out of line.
This is now how the bike starts and idles with no airbox:
http://www.youtube.com/watch?v=gknBb-JSAxE
Wow. Quite a high 'idle'... check throttle cable maybe not springing closed even if twist grip makes u think it is. (temporarily disconnect cable, see if throttle on carb closes
all the way)
Fuel in airbox ? Stuck open float on that side ? Maybe float and/or needle is binding somehow - not assembled correctly, dunno...
See which exhaust manifold gets hottest firstest, that may be the side with the problem because of TOO MUCH FUEL AVAILABLE RIGHT NOW! when u start it , BAM! sky high 'idle' (that's not idle, in the vid)
What air filter u using ?
Miles on bike ? Year ?
This a new problem, how has the bike worked previously ? Knowing these things helps give people an idea where to troubleshoot.
Quote from: bigfatcat on October 08, 2011, 05:00:17 AM
Quote from: elementxero on October 07, 2011, 01:18:32 PM
Per the above suggestion I took the fuel filter out of line.
This is now how the bike starts and idles with no airbox:
http://www.youtube.com/watch?v=gknBb-JSAxE
Wow. Quite a high 'idle'... check throttle cable maybe not springing closed even if twist grip makes u think it is. (temporarily disconnect cable, see if throttle on carb closes all the way)
Fuel in airbox ? Stuck open float on that side ? Maybe float and/or needle is binding somehow - not assembled correctly, dunno...
See which exhaust manifold gets hottest firstest, that may be the side with the problem because of TOO MUCH FUEL AVAILABLE RIGHT NOW! when u start it , BAM! sky high 'idle' (that's not idle, in the vid)
What air filter u using ?
Miles on bike ? Year ?
This a new problem, how has the bike worked previously ? Knowing these things helps give people an idea where to troubleshoot.
I tried detatching the throttle cable entirely and I get the same behavior.
its a '94 with 1900 miles so it sat around a lot...carbs needed a cleaning (stalling issues and high idle/slow return to idle at stops) which is what started this project for me in the first place
So I just tore out the carb and everything looked fine to me, put it back in and its not idling high anymore so it might have just been a stuck float :dunno_black:
EDIT: pre-emptive. it's blasting off to 5k+ as soon as I start it again. WTF! Some smoke out of the right carb after I kill the engine.
I might be at the end of my rope with this--might be time to just put half a grand on my f%$king credit card and have someone with a clue fix my shaZam! because clearly I am a worthless mechanic.
EDIT 2: of course, I can't find any motorcycle repair places in my area that aren't harley-specific.
sigh. i should just burn it and collect the insurance money
Have you checked the carb float heights?
Quote from: elementxero on October 09, 2011, 02:04:26 PM
So I just tore out the carb and everything looked fine to me, put it back in and its not idling high anymore so it might have just been a stuck float :dunno_black:
EDIT: pre-emptive. it's blasting off to 5k+ as soon as I start it again. WTF! Some smoke out of the right carb after I kill the engine.
I might be at the end of my rope with this--might be time to just put half a grand on my f%$king credit card and have someone with a clue fix my shaZam! because clearly I am a worthless mechanic.
EDIT 2: of course, I can't find any motorcycle repair places in my area that aren't harley-specific.
sigh. i should just burn it and collect the insurance money
Rich, with a vacu leak ... ? OEM filter at your jet size 127.5 would do it ... but don't know if it would rev that high that strongly (unless there was quite a vacu leak)
"Smoke" is unburned fuel vapors coming back up out of the cylinder - like you're running rich,
Airbox off: more air with richness = rev monster ? ? makes sense, plus a vac leak, makes more sense
Back the idle stop screw all the way out (though I'm sure u already have), to make sure that throttle is truly closed. Might get the 'idle' down some but probably not...
Check for tightness of intake assembly pipes, and presence/condition of o-rings at the cyl head - http://www.bikebandit.com/1994-suzuki-gs500er/o/m6054#sch232833
When u first start it - quickly check the exhaust pipes for one getting much hotter quicker than the other - may tell u which side has the problem - or, are both equally hot ? ? means possibly entirely different problem.
Consider smaller jets , see what happens, to get that 'idle' down ...
Is the bike rideable even with the high 'idle' by feathering the clutch more ? Can it sustain 60 mph , or does it bog and choke ? ? ?
Starting is almost all pilot jet and air screw, you can over shoot or under shoot a lot and still start.
For example, you can run a 125 jetted bike (stock airfilter+ pipe) without air filter and still work.
You can run a bike jetted for K&N and pipe with stock airbox. It will start, it may not go much further than 5 mph but it will start and hold a 2K idle at a minimum.
I suspect sticky throttle, vacuum leak or a diaphram that can be stuck open etc ...
Cool.
Buddha.