Not startng for seemingly no reason

[cowboyup3371]

Really needing it would be a rusty gas tank. Otherwise, your petcock has a built in filter to it as long as you get one made for the tank and not an inline shut off valve. Check out the ones on Z1's website - www.z1enterprises.com

 

[JaNewb]

cool so I've starting the process of cleaning my carbs but my fuel tank doesn't have a reserve and looking at the petcock on z1 it doesn't seem like it fill fit. Any idea's for a petcock that fits the bolt size on my tank? Or some kind of way to machine something and make the petcock from z1 work?

http://www.z1enterprises.com/ItemDetails.aspx?itemDescription=Petcock+%28vacuum%29+Suzuki&item=KL18-4358

 

[cowboyup3371]

What's the distance in mm between the bolt holes on your petcock?

 

[Maddevill]

One thing to check. My son's CBRF2 would run at idle but as soon as you touched the throttle it would die. Turned out the slides were sticking in the carb bores. Wouldn't lift so would shut off for lack of air. Make sure the slides and bores are clean and move freely along with no tears in the diaphrams.

 

[bluehwy]

One thing to check. My son's CBRF2 would run at idle but as soon as you touched the throttle it would die. Turned out the slides were sticking in the carb bores. Wouldn't lift so would shut off for lack of air. Make sure the slides and bores are clean and move freely along with no tears in the diaphrams.

I wonder if that is what was going on with mine...

His petcock looks like it's the same as my '80 1100E... I bought a Pingel PN# 18-7167 and an adapter plate to go with it. I believe mine measured 50 mm c-c. Want me to verify?

 

[BassCliff]

Hi Mr. JaNewb,

You received your "mega-welcome" in THIS THREAD. (<<<Click) Have you had a chance to go through it? These particular guides, found on my little website, seem to be analogous to your situation:

Mikuni BS(CV) Carburetor Rebuild Tutorial
(Mr. Nessism)
Air Intake Repair:

Airbox removal, intake boots and O-ring replacement
Carb Specs:
Float Height/Jetting/Tuning
​

Carb Notes:
Synchronizing/Troubleshooting/Theory

Feel free to visit my website for electrical tips, valve adjustment tips, and lots of other stuff. Yes, you've got homework.


Thank you for your indulgence,

BassCliff
​

 

[tom203]

What's the distance in mm between the bolt holes on your petcock?

Hard to tell, but his pic looks like he has the dreaded 1980 leverless petcock with 50 mm centerline bolt spacing.

 

[Gorminrider]

"I've had a problem where my bike won't start for seemingly no reason other then not running for a couple days."
Really, I'm not very experienced , but this (from your first post) bugs me.
Your fuel tap is unlikely to be a problem, if gas flows. (There IS a clear airvent in your tank, I hope? Open the gas cap and see if that helps,where fuel flow to the bowls is a problem)
As I understand it, the OEM vacuum tap is really a safety feature so gas doesn't pour out when the motor is off. PLUSyou can ride off on the (warm) bike ...without forgetting to turn the tap on and having the bike die suddenly in traffic...I gather you are used to this already so ok on that score.

Of course, the carb vacuum port for this feature needs plugging,without a similar vacuum-type tap, or too much air goes into that manifold. That's a good point by Steve on a thread not so far from this one...
as to what's going on now? I'm still wondering if there were any changes or maintenance in this period ---->" for a couple days." before which everything was ok? apart from the chilly weather, that is.
and, I'd just tape over the airbox gaps for now. and see what diff it would make. Apparently it ran ok before, so that's a different issue.
oh, well. carry on. tell us if you find anything amiss.

 

[JaNewb]

Hard to tell, but his pic looks like he has the dreaded 1980 leverless petcock with 50 mm centerline bolt spacing.

Yep I just measured it and I'm not sure about the year but it's a leverless petcock, 50mm bolt spacing. As far as I can tell it has a working vacuum line that is functioning.

 

[JaNewb]

"I've had a problem where my bike won't start for seemingly no reason other then not running for a couple days."
Really, I'm not very experienced , but this (from your first post) bugs me.
Your fuel tap is unlikely to be a problem, if gas flows. (There IS a clear airvent in your tank, I hope? Open the gas cap and see if that helps,where fuel flow to the bowls is a problem)
As I understand it, the OEM vacuum tap is really a safety feature so gas doesn't pour out when the motor is off. PLUSyou can ride off on the (warm) bike ...without forgetting to turn the tap on and having the bike die suddenly in traffic...I gather you are used to this already so ok on that score.

Of course, the carb vacuum port for this feature needs plugging,without a similar vacuum-type tap, or too much air goes into that manifold. That's a good point by Steve on a thread not so far from this one...
as to what's going on now? I'm still wondering if there were any changes or maintenance in this period ---->" for a couple days." before which everything was ok? apart from the chilly weather, that is.
and, I'd just tape over the airbox gaps for now. and see what diff it would make. Apparently it ran ok before, so that's a different issue.
oh, well. carry on. tell us if you find anything amiss.

Naw no maintenance at all. Nothing done to it other then the temp dropping 10-20 degrees. That's why I was confused as to how it roars to life one day and sputters out a couple days later. The only thing that changed was the temp. It worked just fine before, no reving at lights to keep the rpms up or holding the starter very long before it starts. It'd turn over like once and fire right up. Was steve's thread about something similiar?

 

[JaNewb]

His petcock looks like it's the same as my '80 1100E... I bought a Pingel PN# 18-7167 and an adapter plate to go with it. I believe mine measured 50 mm c-c. Want me to verify?

If ya could point me in the right direction to what you got I'd be much obliged.

 

[tom203]

Yep I just measured it and I'm not sure about the year but it's a leverless petcock, 50mm bolt spacing. As far as I can tell it has a working vacuum line that is functioning.

Some 1981 gs750s came with the leverless petcock and some had a lever type
Anyway, the leverless petcock has some odd operating functions, especially at getting fuel to flow- maybe the cold has made its vacuum diaphragm sticky.

 

[Gorminrider]

Naw no maintenance at all. Nothing done to it other then the temp dropping 10-20 degrees. That's why I was confused as to how it roars to life one day and sputters out a couple days later. The only thing that changed was the temp. It worked just fine before, no reving at lights to keep the rpms up or holding the starter very long before it starts. It'd turn over like once and fire right up. Was steve's thread about something similiar?

jaNewb, Steve's post here... on bluehwy's thread:
http://www.thegsresources.com/_forum/showpost.php?p=1792157&postcount=17
I had hopes for that to fix it!

I had a similar issue exact to yours a few weeks ago on my GSX400TX. It too starts great no issues whatsoever. But, that day, No start, no good reason except it was two weeks into our winter...What-the-heck! Pulled the plugs, checked the bowls for gas.Something I didn't like about the smell of that gas at that station at that time I bought it...I had put Stabil in it in the fall,too.
Drained the carb bowls, and TANK too-put fresh gas in, turn gas valve to Prime let sit to fill bowls. Choke, Started!
Did I really fix it? Maybe, but sometimes I think an engine just wants a massage.
...the old gas works ok in the car as partial tank...maybe it's" summer gas"maybe it was just nasty when I bought it.

 

[JaNewb]

Some 1981 gs750s came with the leverless petcock and some had a lever type
Anyway, the leverless petcock has some odd operating functions, especially at getting fuel to flow- maybe the cold has made its vacuum diaphragm sticky.

But it shouldn't be a problem to switch it out right? I don't like the fact that I can't turn it off. It makes me worried there is a possible leak or something and flooding my engine. Ah and the thing about the cold is that as an experiment I put oil pan heaters and an electric blanket over it then another cover over it to keep the heat in. Even though it was warmer in there it didn't help.

 

[JaNewb]

jaNewb, Steve's post here... on bluehwy's thread:
http://www.thegsresources.com/_forum/showpost.php?p=1792157&postcount=17
I had hopes for that to fix it!

I had a similar issue exact to yours a few weeks ago on my GSX400TX. It too starts great no issues whatsoever. But, that day, No start, no good reason except it was two weeks into our winter...What-the-heck! Pulled the plugs, checked the bowls for gas.Something I didn't like about the smell of that gas at that station at that time I bought it...I had put Stabil in it in the fall,too.
Drained the carb bowls, and TANK too-put fresh gas in, turn gas valve to Prime let sit to fill bowls. Choke, Started!
Did I really fix it? Maybe, but sometimes I think an engine just wants a massage.
...the old gas works ok in the car as partial tank...maybe it's" summer gas"maybe it was just nasty when I bought it.

Ya this happened once before and it just took a little coaxing to get her up again. Did the same thing I did last time but it didn't work this time.