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Main Area => General GS500 Discussion => Topic started by: rexpepper651 on April 07, 2014, 01:46:21 PM

Title: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 07, 2014, 01:46:21 PM
got my bike running for the first time yeterday since fall and it ran fine. rode to the gas station for some new gas. everything was fine and dandy. today i put in my new rear shock and had to remove the airbox. got everything back together now and the bike runs horrible.

it has no power and was shooting flames out of the exhaust. i put new plugs in yesterday before i started it. im not sure whats going on. pulled my plugs out and here is what i found.


(http://i49.photobucket.com/albums/f272/blacknasty915/DSCN0093_zps0aa20548.jpg)


what would cause the right side to be so black? could i have messed something up when putting the carbs and airbox back on?
Title: Re: low on power, flame out of exhaust on deceleration
Post by: Janx101 on April 07, 2014, 02:19:24 PM
..... Yes ... Right side plug looks horribly rich! .... Check your airbox to carbs seal thingy and clamps etc ... Reckon you have an air leak from a tear or pinched edge there somewhere?
Title: Re: low on power, flame out of exhaust on deceleration
Post by: Big Rich on April 07, 2014, 03:23:17 PM
Actually, an air leak would cause it to run lean. But you're on the right track Janx.

First thing I would look at is either your float height on the right carb (too high and flooding the cylinder) , or maybe a weak spark on that side (swap the plugs left and right and see if the problem follows the plug).
Title: Re: low on power, flame out of exhaust on deceleration
Post by: robfriedenberger on April 07, 2014, 05:00:10 PM
I agree with the weak or intermittent spark idea, if gas is not firing than swap coils


Sent from my iPhone using Tapatalk
Title: Re: low on power, flame out of exhaust on deceleration
Post by: The Buddha on April 07, 2014, 06:29:07 PM
Right is richer than Warren Buffet, left is leaner than Gwen Stefani.

WTH ... I've seen some weird crap one carb to another, but this takes the cake

You have a vacuum leak ? on the 89-00 bike vacuum line is off the left carb ... if that line has a hole in it you can lean the left more than right, but you'd only run on prime in that case.

I have to read your post more slowly ... I'll post back.

Cool.Buddha.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: The Buddha on April 07, 2014, 06:31:42 PM
You pinched some hose getting the airbox out and back in ... or you have a stuck choke or float or something like that is my guess.
It ran fine with the old gas, and craps out with new gas ? That's a first as well.
Cool.
Buddha.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: newbie1993 on April 07, 2014, 08:32:41 PM
Quote from: The Buddha on April 07, 2014, 06:29:07 PM
Right is richer than Warren Buffet, left is leaner than Gwen Stefani.

WTH ... I've seen some weird crap one carb to another, but this takes the cake

You have a vacuum leak ? on the 89-00 bike vacuum line is off the left carb ... if that line has a hole in it you can lean the left more than right, but you'd only run on prime in that case.

I have to read your post more slowly ... I'll post back.

Cool.Buddha.
the plugs from my spark plug thread look like this as well but left looks rich and right looks lean on my Gs

NEWBIE

Title: Re: low on power, flame out of exhaust on deceleration
Post by: BockinBboy on April 08, 2014, 05:52:12 AM
Rex, what really throws up some flags, is that the airbox was removed.  Do you remember what your old plugs looked like since you just swapped them out recently?  ... Did you have white plugs before or black plugs before?  That would tell us what to look for on which side, and what you had going on prior to this issue... my guess is that both were rich or both lean, and now with the recent work, something small went awry.

- Bboy
Title: Re: low on power, flame out of exhaust on deceleration
Post by: The Buddha on April 08, 2014, 06:02:27 AM
Quote from: newbie1993 on April 07, 2014, 08:32:41 PM

the plugs from my spark plug thread look like this as well but left looks rich and right looks lean on my Gs

NEWBIE

If the floats are equal and the air screws are equal, and you ahve not boogered the air screw seat and passage by over tightening it ... then on an 89-00 bike you can have a tiny hole in the frame fuel tap vacuum diagram letting gas over into the vacuum line. To test if that's the case, cap both ends of that line and run it in prime and read the plugs after a few mins.
Cool.
Buddha.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 08, 2014, 08:00:31 PM
ill have to check and see if i have any leaks. it really sucks i dont have time to do anything for like 3 weeks but ill be in vegas so i guess that makes up for it. heres a pic of the old plugs. i dont know which is left or right but they both look the same to me. ill have to check everything out when i get back. the clamps for the carbs to the airbox were pretty bent. i used a steel cup and got them round again but that might be causing the problem.



(http://i49.photobucket.com/albums/f272/blacknasty915/IMG_0180_zps06341059.jpg)
Title: Re: low on power, flame out of exhaust on deceleration
Post by: radodrill on April 08, 2014, 08:19:10 PM
they both like like they've been running lean.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 09, 2014, 10:58:25 AM
not really sure where to start  :dunno_black:  ive never worked on carbs before.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 09, 2014, 07:02:37 PM
alright guys. i had a bit of free time after dinner tonight so i figured id do a little more investigating. i found something interesting an also have a few more questions. lucky for you i like pictures. def alot easier then me trying to explain right?

so i opened up the top of the right carb the one with the black plug and found that there is two short springs in the slide instead of one long one.
this cant be right?

next i have a question about the frame petcock tubes. there is one hidden behind another. you can see in the pic below. now is this suppose to be connected to a tube with a T in it? if so does it actually connect to anything? mine has always just been sitting between the right an left carbs.


i checked both sides to make sure each was getting good spark and indeed was.


(http://i49.photobucket.com/albums/f272/blacknasty915/IMG_0195_zpsbae7a7fc.jpg)

(http://i49.photobucket.com/albums/f272/blacknasty915/IMG_0194_zps34585f0d.jpg)
(http://i49.photobucket.com/albums/f272/blacknasty915/IMG_0196_zps0b0d55c9.jpg)
Title: Re: low on power, flame out of exhaust on deceleration
Post by: Janx101 on April 09, 2014, 07:35:38 PM
unless there are different frame petcocks for older/newer bikes ... or in different countries? ... that doesnt look like a OEM petcock?

but i have heard some of the guys here refer to a pingel petcock?... never seen one though..

and though i dont know specifically... i would think that .. yes that t joint is supposed to go somewhere?.... or its a blank and has been jammed into the pipe just to block it?
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 09, 2014, 07:42:26 PM
yeah i couldnt figure it out when i was putting everything back together after the shock swap. i havent see any other petcocks before so not sure if thats right or not either. its hard to read the tube chart to. so much going on in one little photo.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: Janx101 on April 09, 2014, 09:16:15 PM
ok.. found this image... says its a pre 2001 petcock .. looks just like yours...

(http://beergarage.com/imgs/GS/Petcock/17.jpg)

whereas my '06 petcock looks like this on the left ... the right side thing is the fuel tank petcock

(http://www.gdlcycles.com/general/246-13091-Petcock-1.jpg)

is it this photo you looking at for vacuum hose routing?..... its one of the clearer ones for me to understand!?

(http://i205.photobucket.com/albums/bb17/ben_2_go/Motorcycle%20Stuff/Vacuumhoserouting.jpg)
Title: Re: low on power, flame out of exhaust on deceleration
Post by: Janx101 on April 09, 2014, 09:29:07 PM
and a link for Kerrys page .. if you havent seen it already!

http://gstwin.com/fuel_hose_routing.htm
Title: Re: low on power, flame out of exhaust on deceleration
Post by: gsJack on April 10, 2014, 04:56:25 AM
Quote from: Janx101 on April 09, 2014, 07:35:38 PM
unless there are different frame petcocks for older/newer bikes ... or in different countries? .................

There are 3 different kinds older, newer, and the in between 01-02 ones like I have.

(http://www.gs500.net/gallery/data/500/GS500fuelcocks.jpg)
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 10, 2014, 07:05:47 AM
awesome! both helped. my bikes older yeah. so that hose coming off the frame petcock is just left open so ill take that white T out.  ill have to get another hose for the one that goes over the airbox an figure out where it goes. hopefully this is my issue. got new springs ordered and new clamps for the carbs and airbox.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 10, 2014, 07:14:04 AM
Quote from: rexpepper651 on April 10, 2014, 07:05:47 AM
awesome! both helped. my bikes older yeah. so that hose coming off the frame petcock is suppose to go to the left carb and  ill have to get another hose for the one that goes over the airbox. i dont have that one at all. hopefully this is my issue. got new springs ordered and new clamps for the carbs and airbox.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: piresito on April 10, 2014, 07:39:51 AM
Quote from: rexpepper651 on April 09, 2014, 07:02:37 PM

so i opened up the top of the right carb the one with the black plug and found that there is two short springs in the slide instead of one long one.
this cant be right?


That's not two springs, that's one spring. The way it's particles are displaced may confuse you though...  :cookoo:
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 10, 2014, 07:42:24 AM
yeah my buddy pointed out to me the two ends that are sharp looking means it broke! glad they are only 5 bucks!
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 10, 2014, 08:08:39 AM
would these be the correct pilot jets for my 97?  http://www.partzilla.com/parts/detail/aftermarket/XP-4459739.html (http://www.partzilla.com/parts/detail/aftermarket/XP-4459739.html)
Title: Re: low on power, flame out of exhaust on deceleration
Post by: BockinBboy on April 10, 2014, 11:05:54 AM
That mystery tube on the petcock is the vacuum hose, and it should be connected to the left carb.  I'm not familiar enough with the 89-00 model tubing to tell you why there would be a 'T' connection on there though...

- Bboy
Title: Re: low on power, flame out of exhaust on deceleration
Post by: gsJack on April 10, 2014, 01:04:28 PM
Only "T" is in fuel line, only a single vacuum hose to top inside of left carb.  From 89-99 Shop Manual:

(http://www.gs500.net/gallery/data/500/Fuel_System_89-00.jpg)

(http://www.gs500.net/gallery/data/500/Fuel_Hose_Routing_89-00.jpg)
Title: Re: low on power, flame out of exhaust on deceleration
Post by: BockinBboy on April 10, 2014, 01:11:51 PM
Yeah, that's what I thought Jack, thanks.  It looks like the 'T' he has is much too small to be the one for the fuel line that goes to each carb. 

If it were an '04+ I'd say the 'T' on a vacuum line goes to pair system and other to carb (IIRC, haha), but he definitely doesn't have that setup anyway... so this small 'T' on the vacuum line is a mystery to me... vacuum from petcock should go to left carb only on 89-00 models.

- Bboy
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 10, 2014, 01:38:31 PM
so sweet diagrams!  thank you! now the wonderful wait on parts  :technical:
Title: Re: low on power, flame out of exhaust on deceleration
Post by: gsJack on April 10, 2014, 05:01:23 PM
There is another "T" between the carbs at the top of the bowls for the bowl vent hose that runs back over and down behind the air box and vents to atmosphere.  This is important, can cause running problems at high speeds and/or with strong cross winds if not placed right.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 10, 2014, 05:56:54 PM
 i got the one on the top of the carbs in the middle that has a T in it running down under the airbox and pointed at the ground. found the missing tube location for the frame petcock located on the right side of the carb on the clutch side of the bike.  :woohoo: getting closer! now its just the waiting game for ups to bring parts and vacation to end. thanks for all the help everyone! hopefully ill have success!


the weather has been so nice the last couple of weeks i wish i could of been out riding. been a long winter here!
Title: Re: low on power, flame out of exhaust on deceleration
Post by: Janx101 on April 10, 2014, 06:04:37 PM
 :thumb: good to hear bro!!

insert corny vid !!

Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 10, 2014, 06:38:41 PM
Quote from: Janx101 on April 10, 2014, 06:04:37 PM
:thumb: good to hear bro!!

insert corny vid !!





haha thats totally going to be me!  :cheers:
Title: Re: low on power, flame out of exhaust on deceleration
Post by: BockinBboy on April 11, 2014, 08:48:04 AM
The 'T' on top of the carbs that goes toward the airbox - That should be routed over the top of the airbox, and terminate between the airbox and battery = can't move, no kinks, and out of any wind = ideal routing and location.  :thumb:

- Bboy
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 11, 2014, 08:51:39 AM
Quote from: BockinBboy on April 11, 2014, 08:48:04 AM
The 'T' on top of the carbs that goes toward the airbox - That should be routed over the top of the airbox, and terminate between the airbox and battery = can't move, no kinks, and out of any wind = ideal routing and location.  :thumb:

- Bboy

fantastic! thanks! ill move it asap!
Title: Re: low on power, flame out of exhaust on deceleration
Post by: BockinBboy on April 11, 2014, 08:55:53 AM
Oh, one more thing on that - place it so that it goes to the side of the air box inlet - you don't want it going across the intake opening and restricting air flow there.  On newer models there is actually a clip for it to run on the right side of the top of the airbox, but I don't know if the older models included that.  It's just a little band thing that is screwed in with one of the filter screws on the right side - not completely necessary but it is helpful with routing and keeping it in place.

- Bboy
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 11, 2014, 09:41:22 AM
im just curious. if this tube was incorrectly placed like i have it. what kind of effect would it have on the bike?
Title: Re: low on power, flame out of exhaust on deceleration
Post by: BockinBboy on April 11, 2014, 09:56:48 AM
At speed, it would bog down, sometimes its enough that the bike shuts off.  A lot of folks who switch to a lunchbox filter (no airbox) have trouble with it.  Just a crosswind can be enough to bog the bike and shut it down if its exposed too much.

- Bboy
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 11, 2014, 10:05:15 AM
i think i know what youre talking about actually. i noticed my bike will like slow and speed back up in the slightest amount. not really noticeable by the mph but in the feeling while riding on the highway but this could also be due to the poor workmanship that was done prior to me owning it.
Title: Re: low on power, flame out of exhaust on deceleration
Post by: rexpepper651 on April 26, 2014, 06:54:41 AM
well back from vacation  :sad: got my slide springs in the mail. got everything put in and i noticed my float bowls were on the wrong sides so switched those around so i looked at my main jet size and it says its a 122. now i dont know if they dynojet jets or not. according to the chart on wiki i need a 127.5 and a 40 pilot. i havent tried running the bike yet. still doing some other work on it. i had a picture on here of my old plugs and some said it was lean. so replacing the jets, adjust the mixture screw and then sync the carbs. and take her for a ride and then inspect the plugs. this all sound about right? oh and so i have needles with the c-clips which position would it go in? 3rd from the top?