The bike is a 95, with 01 carbs and has been my runner for 3+ yrs. Have put 3-4k on it.
Has yosh slip on Ti trioval pipe, stock filter in airbox and 132.5/20/1 washer/3 turns.
Carbs are clean, air filter is clean, valves are loose end of spec. Floats are set right, carbs are synched.
It used to bog at take off when its cold. But 2 mins after starting it and bogging 1-2 times, it will rev fine, make tons of power and like like a scalded dog.
It ran great Wednesday morning and evening inspite of the 2 mins of bogging in the beginning. Made 90 indicated or so on the way home Wednesday afternoon.
Thursday morning - starts, but makes no power, cant ride off on it, it starts and idles and sounds great, but the thing will not rev, and sounds hollow when you rev it, and it wont have any power to ride. Start to let out the clutch and it will stall. I can start it immediately, and it seems to not ever get to where it does not bog.
I'll post what it turns out to be. But any ideas are welcome.
Cool.
Buddha.
Zero power, hollow sound. Those were symptoms of my bike when a coil failed.
But if a coil failed wouldn't that require you to turn up the idle screw to get it in the proper range?
My guess:
Running on one cylinder. Suddenly caused by a clogged main jet or sticking needle. Or an electrical issue - faulty plug, loose connection to a coil. Basically carbs or electric, could be spun Piston rings lining up causing a loss of pressure.
I dont think its losing 1 cyl, but I'll check. I stripped a rotor cover bolt, so I have to drill it out and look at it today. Plus the coils on the frame.
The bike needs all the rings and everything else to be intact to idle. Idle makes the most vacuum, so I doubt it is related to the rings not sealing.
Clogged jets - definitely not. All clean and purty.
Back to the mystery now.
Cool.
Buddha.
My guess.....could be water in the gas, maybe someone took a pi** in your tank on weds night.
:D :D :D
Ha ha sledge.
OK I'm ruling out electrical.
Why ??? - on choke it revs to 4k-6k. On throttle it lacks power and not rev past ~3k.
Anyway - I am circling this theory. May explain most if not all symptoms.
Floats are high - one is worse than the other one but they are high. But I believe they are progressively getting worse. Also I am very reluctant to adjust floats on an 01+. That makes it likely that its the culprit. Maybe leaking, maybe an issue with one of em "sinking"
Cool.
Buddha.
Have you checked the temps of your exhaust header? That would be a dead giveaway of a dead cylinder
Not really in this case, its running on both on choke. And revving to 6k, give it throttle and if it loses a cyl - which it probably would with a float that is too high - I certainly cant touch and tell which one is not firing before I lose a finger or 3 ...
Cool.
Buddha.
Hi Buddha , same problem here 2007 GS 500 F , how high were the floats , I keep thinking its electrical , but I am making black smoke sometimes , however spark plugs look great , I put trickle charger on every night when I get home , starts right up , leave sit for 12 hours ( no trickle charger on ) , and guess what hard to start , well in the next day or two I am taking carbs off , taking them to whittier Kawasaki , and putting new floats , new needles , new seats, new jets , clean carbs complete , complete overhall on carbs , as all the above parts are 9 years old , 16,000 miles on the clock , had new battery checked out , well tonight I am gonna check the connection on the starter and see if loose . anyways let us know how you are coming along .
Just for ruling things out....have you run a compression check?
gonna have to get a compression test kit
Buddha , do you have any oil in the airbox ? maybe some blow-by , worn down piston rings , how many miles on bike ? air filter have some engine oil on it ? do to blow-by .
Air box is clean, no gas or oil on filter. Dry and clean.
Has tons of power, or has when it ran. Compression is probably fine.
I gotta check out my theory tomorow.
My floats may have been high enough to drown out the air intake jets in the filter mouth. AKA, essentially choked itself in gas, but maybe my dry sound - wasn't a very good description.
Cool.
Buddha.
hey Buddha , really sounds like high float level = less performance . what I am going to do is buy brand new floats . as I can smell very rich mixture out tailpipe . did you check starter wire to battery , make sure its not loose . :thumb:
Quote from: Alan_nc on March 27, 2016, 01:43:01 AM
Just for ruling things out....have you run a compression check?
+1
Rg500, it might not be necessary to buy new floats, you could try adjusting the ones you have
Quote from: lucas on March 25, 2016, 05:43:22 PM
Zero power, hollow sound. Those were symptoms of my bike when a coil failed.
But if a coil failed wouldn't that require you to turn up the idle screw to get it in the proper range?
+1
Buddha, you might be able to tell if you have a cold, dead cylinder by holding the back of your hand near the headers. When I had a dead cylinder one header was 300 to 400 degrees Fahrenheit colder than the other.
Quote from: lucas on March 27, 2016, 10:11:36 PM
Rg500, it might not be necessary to buy new floats, you could try adjusting the ones you have
yes I will try that . many thanks for the tip . :thumb:
Quote from: lucas on March 27, 2016, 10:14:01 PM
Buddha, you might be able to tell if you have a cold, dead cylinder by holding the back of your hand near the headers. When I had a dead cylinder one header was 300 to 400 degrees Fahrenheit colder than the other.
+2
OK issue fixed (I hope)
I set floats rather low (leaving too little fuel in the bowl) - Issue persisted.
Then I took off the floats and dropped em in gas - no sinky. All floaty. Grrrr
That last time when I pulled the carbs I tipped em over into the gas can (to empty the bowls - yea they say never to do that, but I have cleaned the carbs 300 times and opened it up 350 times the last 4 days, so I knew it was not going to get any more junk into the jets). And I blow tested it. It blowed through fine, and it nicely sealed up too.
Then I put it back on and tried it ... and vroom vroom.
Ergo - I either had a blocked vent to air from the carbs, or had a fuel line block ... or a gremlin climbed in and ruined it, and it ran away and its fine. If it ever comes back, I'll be in trouble.
Cool.
Buddha.
You need a gremlin bell. Ha.
Well, it's good the bike is up and running again!
It was bad for over a year, and it got suddenly unuseable. It would still idle perfectly.
I am leaning toward that top vent, cos a blocked fuel line wont flow better when the fuel useage is a tiny fraction of the max @ speed.
Cool.
Buddha.
And its gone back to the way it was before it completely went kaput.
I suspect something is clogging up the fuel passages.
Cos the last few times I pulled it apart, I got something in the fuel line that looked grey sediment like.
And not coincidentally, the tank is coated with POR15.
I suspect its coming loose.
I may re run it with that black tank I ran it a few yrs and try checking this one.
Cool.
Buddha.
Tank is clean. POR15 isn't coming off and gumming up
OK ... this is a first (for me) but someone has sent me a carb rack they said had a leak @ the butterflies. I used it for parts and tossed the carcass a few yrs ago. There was a leak in that @ the pivot.
Also how can that affect both carbs. I suspect whatever it is, is pertaining to both carbs. I'll trouble shoot more and post back.
Cool.
Buddha.
It also sounds/feels like the slides are coming up too fast.
Except, they have been @ this setup for 3k miles, and it was always acting up when cold, but 30 sec after trying to take off, it would get normal and stay fine till the next cold start.
Cool.
Buddha.
Buddha , will bike go up a steep hill ( i.e. Colima road by me in whittier ca.) at 60 m.p.h. ?
Quote from: rg500gamma on March 29, 2016, 07:30:55 PM
Buddha , will bike go up a steep hill ( i.e. Colima road by me in whittier ca.) at 60 m.p.h. ?
No It wont even go up a not too steep hill. It barely goes up my driveway.
Cool.
Buddha.
do you have another set of carbs to try?
Quote from: vipster76 on March 30, 2016, 01:13:43 PM
do you have another set of carbs to try?
+1 really need to try a second set of carbs. if bike cannot go up a hill at 60 m.p.h.
I know its the carbs. The thing is, the cable has been modded for an 01-02 carb set. So I'll need a 01 or later, but I am pretty good @ doing repairs 1 at a time and testing it out. How else do I learn ???
Anyway - My next stop is to slow down the slide's lift rate.
Cool.
Buddha.
Buddha, have you verified that you are getting spark to both cylinders?
Also if you check the temps of the exhaust tubes you might narrow your search down to one side of the engine. If you have a meat thermometer, kitchen thermometer, or even touching the exhaust tubes with an oven mitt and comparing the heat transferred by each.
OK now that the weather is warmer (I guess) it seems to take for ever to warm up, and as it does it will start accepting throttle, it will rev to 3k before choking or gasping, a few mins later it will rev to 4k, few mins later 5k, few mins later 6k and 7 and so on.
I have not tried to ride it. It may still not make power. Revving is different form making power.
Cool.
Buddha.
You could try pulling the spark plug wires while it is idling to see if the rpms change. While you're doing this you can visually verify that you are getting sparks by holding the open end of the wire close to the end of the spark plug and watching for arcs to jump out of the open plug wire.
And this morning it didn't even seem to act up at all. I dunno what I even did to fix this, if I even fixed it.
Its got both cyls running, it falls on its face when you rev it but not lose a cyl, the thing just feels like its getting too much air, that was when it was acting up.
Its rather similar to the symptom when your slide rises too fast. But that usually happens 1/4 throttle and up, and you can get it to work right with slower opening of the throttle.
Cool.
Buddha.
It acted up a wee bit today. But 2 mins of idling after 1 min of choke - and it was running like a champ.
I am still a shade lean @ 1/2 throttle, cos I got rid of 1 washer from the needle. Gotta get back to the thing and put it back in.
Cool.
Buddha.
And on my way back from work today it acted up for a good 3-4 mins. But about 1/8th mile and 2 lights of screaming on choke later, it caught its breath and ran like the proverbial scalded bat out of hell - for a GS that is.
Is it possible the slide is lifting just a shade too fast when cold, but the bike is able to process the extra air and fuel when hot ????
I'll slow the slide down and try next.
Oh yea, float level is low too. Gotta fix it next try I'm in there.
Yea the valves are wee bit loose. But just a little racket, that's all. Compared to the Yoshi Tri oval howling away, its just a little music.
Cool.
Buddha.