Hey all this is my first motorcycle and my first time working on a carbureted engine, I bought this bike today and in Vancouver BC Canada and PO told me carburetor not getting fuel. I just turned 17 and had always wanted to ride a motorcycle but worried about parents opinion so I waited till a REASONABLE age.

As a side note I purchased this bike for 1000$ in my eyes it was an absolute steal! Bike is in great condition cosmetically and the inside of the gas tank from what I see which is grey silver looks great.

I took it home and tried to start it it turns over beautifully oil level is perfect but not start, I first started by taking apart the carburetor's and found the main big jet to be absolutely disgusting and filled with sand like crud so I cleaned it all out and the original gaskets didn't fit the damn float bowl I guess the PO didn't set it properly cause it's a little disfigured so I have it all bagged securely and in my garage waiting for my paycheck to buy a carb rebuild kit.

Another problem I found was that the left cylinder spark plug/wire isn't working I actually do not know how to test a motorcycle coil pack so if anyone can shed some light I'd greatly appreciate it. The right cylinder has spark although it is red and doesn't look to strong, the battery seems to be fully charged but I will use a multimeter to test it's output.


tl;dr Cranks but no start took apart carb jets were dirty cleaned, left cylinder no spark right cylinder weak spark, waiting on carb rebuilt kit.

Just asking if there's anything else that could contribute to the no start I have currently I believe it's just the carb jet being super clogged but the left and right cylinder spark is worrying me aswell.

Sorry for the lengthy post and not so clear descriptions if anyone wants me to re-clarify some things or take photos I am happy to do so as a teenager with absolutely nothing else to do but work on a BEAUTIFUL motorcycle!! 

Here's some photos I took today

(sorry gotta crop it properly!)

I've been searching for a good quality carb rebuild kit and the only one I could find for a reasonable shipping cost is this it's around 100$ usd with shipping and import tax. Are there any other options?

https://www.motorcycleid.com/all-balls/carburetor-rebuild-kit-mpn-26-1662.html?singleid=1579108232&url=126828700

I'm not much help when it comes to carby stuff (mine have been exceptionally good to me so far) but I can provide this link here:

https://joshkarnes.blogspot.com/2017/09/fixing-common-gs500-carburetor-issues.html

...and as for the testing, maybe this will help:

http://www.bbburma.net/Documents/JohnBates_ChargingCircuitTests3.pdf

I wanted to say welcome to the forum and congrats on the bike. I bought my GS for that same price back in 2012 and I'm still in love with it today.

Much love from Western PA

For me that would be about £600 and twice I would be prepared to pay for a non running 17 year old GS5 with 41K on the clock.

I don't want to appear condescending................but I hope all this works out for you 

My suggestion is that your next step is to buy a Haynes manual and read it cover to cover, then read it cover to cover again

No spark in 1 cyl may be the auxillary ground. The 04 has a single trigger coil right, then it cant be the issue cos then you'd have no spark in both cyls.
Fix the carb and make sure that thin wire from the battery negative makes good contact at the plug right by the battery. Then if you have it only run on 1 cyl, see what happens when you swap the ignition coils. If the problem follows the coil, that's the problem.

Cool.
Buddha.

Quote from: sledge on July 24, 2021, 05:23:07 AM
For me that would be about £600 and twice I would be prepared to pay for a non running 17 year old GS5 with 41K on the clock.

I don't want to appear condescending................but I hope all this works out for you 

My suggestion is that your next step is to buy a Haynes manual and read it cover to cover, then read it cover to cover again

PO gave me a haynes manual really good information in there.

Quote from: The Buddha on July 24, 2021, 05:40:04 AM
No spark in 1 cyl may be the auxillary ground. The 04 has a single trigger coil right, then it cant be the issue cos then you'd have no spark in both cyls.
Fix the carb and make sure that thin wire from the battery negative makes good contact at the plug right by the battery. Then if you have it only run on 1 cyl, see what happens when you swap the ignition coils. If the problem follows the coil, that's the problem.

Cool.
Buddha.

Thanks!

Congrats on the bike. Ignore Sledge, he's mean to everyone.

That price actually sounds cheap to me based on when I lived in eastern canada, and in the current environment you actually can't buy bikes, so prices have skyrocketed. Assuming there is nothing catastrophically wrong  with the engine of course.

It's going to be a bit tricky, Canada is not easy to get parts, and you get knocked by the expensive american shipping and the import duties on the Canadian side. I found that Ron Ayers and Rocky mountain ATV had reasonable shipping and a good selection. But my knowledge is now a few years old. Once you get to cross the border again it might be easier.
A word of advice, no matter how much you are tempted, don't miss with the jetting.

So if it won't start due to FUEL, then the pilot jet is the problem area, not the main jet. But you should do a carb rebuild anyway, replace all three jets in both carbs and EVERY SINGLE o-ring.

While you have the carbs off, go ahead and pull the intake boots and inspect them, replace the big o-rings. They probably need it.

With 41K I would be doing a compression test ASAP to make sure I wasn't in for a top end rebuild. Might as well get it all overwith at once IMHO.

And FYI this forum has an "ignore list", which is pretty good for folks like sledge. That's a pretty decent cosmetic looking GS for the money but that is a fairly lot of miles on it and there's a lot more than just carbs that will likely need attention... fork seals, rear shock, clutch cable, valves/head/rings, etc. But at least it will look good once you get it sorted mechanically.

Can I suggest when you are finished rebuilding the carbs and have managed to get it running you finish the job off properly and balance them. At that mileage and after the rebuild they will almost certainly be out of sync` 

Unfortunately, in his wisdom, the last contributor seems to have overlooked this small but valuable and very basic piece of advice 




Perhaps it was down to the fact he seems more interested in telling you to ignore me   

Quote from: herennow on July 25, 2021, 03:09:16 AM
Congrats on the bike. Ignore Sledge, he's mean to everyone.

That price actually sounds cheap to me based on when I lived in eastern canada, and in the current environment you actually can't buy bikes, so prices have skyrocketed. Assuming there is nothing catastrophically wrong  with the engine of course.

It's going to be a bit tricky, Canada is not easy to get parts, and you get knocked by the expensive american shipping and the import duties on the Canadian side. I found that Ron Ayers and Rocky mountain ATV had reasonable shipping and a good selection. But my knowledge is now a few years old. Once you get to cross the border again it might be easier.
A word of advice, no matter how much you are tempted, don't miss with the jetting.

I found this youtube "fortnine" whose based in vancouver and sells all kinds of motorcycle gear and parts so I'm gonna try out there carb rebuild kit.

https://fortnine.ca/en/all-balls-carburetor-rebuild-kit-26-1662

So I got the all balls carb rebuild kit yesterday I installed the new jets except for the big one because it wasn't included in the rebuild kit, put on the float bowls attached the choke, throttle cable, air box then popped the carbs into the bike and started it up.

It starts and runs but it's very rich and full choke goes to 7k rpm and rises w/o choke stays at 3k rpm then steadily declines then stalls, I can keep it running with the throttle but it eventually dies with no choke or idles at 7k rpm and rises at full choke. I'm a little worried I screwed something up but all I did was install the new jets and removed the idle air mixture screw and threaded it in by eyeball to where it was before.

I'm not sure what to do other then take it all apart and mess with the fuel mixture screw, but what about the choke and a bit of backfire. Also another weird thing is that when I disconnect one of the spark plug wires and full choke it goes to 3k rpm and stays there but when I plug back in the wire it shoots up and rises.

VERY strange behavior so I probably screwed something up just not sure exactly what

here are my symptoms TL;DR

FULL CHOKE 7k rpm rises

NO CHOKE 3k rpm steadily declines stalls

can keep bike running by holding accelerator

spark plugs black and smells rich

removing spark plug wire makes bike run better

back fires a bit



Sorry for the weird formatting I cut my fingers so typing is really tough ATM

IIRC, the mixture screw must be 2,5 turns out as a starting point

Idle can be all over the place until you adjust the idle hot (20 minutes at least of riding)

Are you sure you are getting enough gas (petcock is on prime, you get a good flow from carb carb drain if you drain it from the bottom drain into a measured container, maybe 200 ml per minute.

But the kicker is , what do you mean it runs better when removing plug wire. Dont remove plug wire! you force the coil and ignition to do unnatural things that way. By all means remove the plug wire, attach a spare plug, lay it on the engine to ground it and then try, but never just run an engine with a plug wire removed. you can destroy the coil (unlikely) and the ignition (likely if done too often.)

Quote from: herennow on August 04, 2021, 11:04:05 PM
IIRC, the mixture screw must be 2,5 turns out as a starting point

Idle can be all over the place until you adjust the idle hot (20 minutes at least of riding)

Are you sure you are getting enough gas (petcock is on prime, you get a good flow from carb carb drain if you drain it from the bottom drain into a measured container, maybe 200 ml per minute.

But the kicker is , what do you mean it runs better when removing plug wire. Dont remove plug wire! you force the coil and ignition to do unnatural things that way. By all means remove the plug wire, attach a spare plug, lay it on the engine to ground it and then try, but never just run an engine with a plug wire removed. you can destroy the coil (unlikely) and the ignition (likely if done too often.)

When it ran on 1 cylinder the idle was much smoother and it didn't backfire and wouldn't rev up to 7k rpm and rise with full choke. So adjusting the mixture screw will solve the misfire and running to rich?

I'm still confused about the choke, it's also pretty hard to open and close (not smooth)

there's a screw that sets tension on the choke lever. Loosen it a tiny bit, choke lever will move easier.

Are you sure you got the right rebuild kit? Sounds like you might have gotten a Mk1 rebuild kit with like 37.5/122.5 jets and put them into the Mk2 carb in place of the stock 17.5/60 jets, in which case it would run extraordinarily rich. Or otherwise maybe you put the mid/main jets in place of the pilot/mid? I would look at the jets first.

It does sound like it's running extraordinarily rich.

You could also have the float level way to high or leaking, incorrectly installed float needle valves, leaking float needle seat, etc.

Took apart the carbs again (not knowing I didn't need to) adjusted the fuel mixture screw 2.5 turns out exactly with spring and o ring (as a side note the fuel mixture screw was hard to turn and didn't turn smoothly idk if this is just because of the spring). Slapped it back on and it started! Still have the same problem with full choke 7k rpm and climbing but I just turned off the choke and held it with the accelerator waiting for it to warm up. It sounds really nice and doesn't backfire anymore and revs smooth, I've actually found out that it really is only running on the right cylinder as I unplugged the spark plug wire nothing changed and sprayed some wd40 on the exhaust and it didn't evaporate as quickly as the right cylinder. I got my friend bringing over a compression test kit tomorrow as I do have spark because I let the spark plug on the air fins and saw the spark, I do believe I have fuel and air because the float bowl is full and the spark plug is black.

I'm not 100% sure what is wrong with the left cylinder but I have gotten it to idle at 3k rpm happily I tried adjusting the idle screw but it doesn't respond to it very well as in it doesn't adjust enough. So currently just gotta fix the choke and diagnose what's wrong with the left cylinder, it also starts right up when it's hot!! very good sign for the future. I couldn't tell you how many times I've had to pull the gas tank and remove the gas lines so I'm definitely going to look for a solution to this problem.

Also theres this small brass vacuum port or something on the left cylinder side I'm not sure what it is or what it does so if anyone knows what I should do let me know!

Carbs

https://imgur.com/a/m1kzXNx

https://imgur.com/a/EQx2BkB

https://imgur.com/a/cdVPnq8

https://imgur.com/a/hL9RhzG

Vacuum port??? left side

https://imgur.com/a/3OiQabU

Spark Plugs right cylinder

https://imgur.com/a/S93dQ6h

Vids

https://www.youtube.com/watch?v=2D9FclwKPB4

https://www.youtube.com/watch?v=TMb2t1UETno

https://www.youtube.com/watch?v=nJ6RX-a5zEw

https://www.youtube.com/watch?v=bVNQqXzQwhQ

I'm also wondering if I made the mixture to lean I did 2.5 turns from bottomed out but the spark plug does look a tad burnt (I'm not a professional spark plug reader) and it does have a high idle and can't hold below 3k rpm but this could also be because it's running on 1 cylinder.

heres some more spark plug photos of the right cylinder

https://imgur.com/a/VOjIYWK

https://imgur.com/a/PYBPDWz

The left carb tube need to be capped off. Mine cracked and cause a rev surge.

has to get a lot of air and fuel to idle at 3K.

could be the choke stuck on. But once the bike warmed up it would die if this was the case.

3k idle warmed up means there's a massive air leak somewhere or you have the idle stop really cranked.

as you might expect, running on one cylinder alone will make it idle very slow and run like garbage. like 500 rpm idle, barely run. That's because one cylinder has to push the other one around with no help.

Quote from: mr72 on August 11, 2021, 09:27:04 AM
has to get a lot of air and fuel to idle at 3K.

could be the choke stuck on. But once the bike warmed up it would die if this was the case.

3k idle warmed up means there's a massive air leak somewhere or you have the idle stop really cranked.

as you might expect, running on one cylinder alone will make it idle very slow and run like garbage. like 500 rpm idle, barely run. That's because one cylinder has to push the other one around with no help.

choke isn't stuck it fully engages and disengages with a little convincing but my idle stop screw is hard to turn and doesn't seem to change the idle anymore, I'm gonna try again tomorrow but I think the left cylinder is firing now but on cold startup today when I plugged the vacuum port today there was a loud bang then it started and it backfired a bit on the deceleration of rpm when I revved it only when cold. When the engine was hot no backfire at all, I'm gonna upload another video of it cold (dont worry abt the smoke thats just me making sure the exhaust is warming up.

I'm definitely looking into doing a valve adjustment I just want to make sure that's not the ONLY reason this is happening.

https://www.youtube.com/watch?v=daeqNkSPApA

Also does anyone know any motorcycle part places, I see that fortnine is really good for canada but it's from montreal and parts take a week to get to Vancouver BC and they don't have a great selection. I'm also not to keen on ordering parts from the USA as import charges are annoying and it takes a long time for it to ship.


Oh and I uploaded the pics of the exterior of the carbs to see if anyone noticed if any of my vacuum lines are wrong, I know there routed AWFULLY but with how much I take everything apart it's a hassle to make it all neat and tidy to just take it all apart again.

Let me know if the vacuum lines are wrong thanks!