Fuel petcock

[Apples]

So, I have this 1978 GS1000 that I need a new petcock on. Problem is, none of them look like what I have. I ordered one that said it fits, but it doesn’t. I’m guessing I have a different tank? Any ideas on which petcock to get? 

[Hariii]

Yeah, the one you have should be a cheap replica fitting the GS 750. You will probably need something like this:

https://www.Eblag.at/itm/KR-Benzinhahn-Fuel-tap-FPC-306-SUZUKI-GS-550-850-1000-GSX-750-1100-1980/161109280230?hash=item2582dc85e6:g:QXQAAOSw~y9ZAcFg

[Apples]

I think I figured it out. Now what I really want is one that isn’t vacuum only and has an actual shut off on it. It looks like there is a key or something for this, but no matter how much I spin or push it, it doesn’t seem to do anything. 

[gs7_11]

You have the later tank with 50mm hole spacing, so none of the 44mm taps with levers will fit unfortunately.

The 50mm tap has a screwdriver slot with 'prime' and 'on' positions only, no off or reserve.

[Apples]

4 hours ago, gs7_11 said:

You have the later tank with 50mm hole spacing, so none of the 44mm taps with levers will fit unfortunately.

The 50mm tap has a screwdriver slot with 'prime' and 'on' positions only, no off or reserve.

Yeah, it looks like its from a 1980-82ish bike and not the original tank for this bike.  Whoever had this bike before me really tried hard to get it going without knowing what they were doing.  Whoever designed a petcock without an off position is an idiot.  I love it when gas slowly leaks into the carbs when the bike sits.  I think I figured out the prime position finally but it doesn't seem to draw enough vacuum to open the petcock up.  

[Gixer1460]

40 minutes ago, Apples said:

 Whoever designed a petcock without an off position is an idiot.  I love it when gas slowly leaks into the carbs when the bike sits.  

Nowt wrong with vacuum fuel taps - i've had loads of bikes fitted with them and never had an issue, most even had an 'Off' position that I never used!

[wraith]

The vacuum taps work very well on most bikes, the only time people have problems with them is when the rubber ring/spring/diaphragm gets worn and they start leaking.  on/off taps can do the same when they get worn.

[Apples]

My last bike worked well with the vacuum tap too.  It worked well.  This fuel system is just getting to me.  It hasn't helped that my shop hand turns 5 this week and has been a little distracting as I've been working.  With the few minutes I messed with it last night I couldn't get the prime position to work.  I see that you have to turn it with a screwdriver a quarter turn and then turn it over to hold the valve open.  I'll try again tonight and hopefully my shop hand is busy doing something else.  

[RGSX]

Vacuum left me stranded a couple times, until I changed out the 35 year old vacuum line.

[Apples]

55 minutes ago, RGSX said:

Vacuum left me stranded a couple times, until I changed out the 35 year old vacuum line.

Personal record for a vacuum line?

[RGSX]

9 hours ago, Apples said:

Personal record for a vacuum line?

it was abandoned in shed for 25yrs,

[Gixer1460]

6 hours ago, RGSX said:

it was abandoned in shed for 25yrs,

And it didn't occur to you to change anything rubber - just cos it 'looked' ok?  

Ride behind this man guys - he has 35+ year old brake hoses! 

[RGSX]

2 hours ago, Gixer1460 said:

And it didn't occur to you to change anything rubber - just cos it 'looked' ok?  

Ride behind this man guys - he has 35+ year old brake hoses! 

vacuum line was plastic, it doesn't break down, it lost elasticity.

Brake lines were absolutely fine, passed government registration inspection, just as the lines on my 42 yr old bike did. I've since upgraded both rides to SS lines for better braking performance not because there was anything physically wrong with the lines.

[Apples]

11 hours ago, RGSX said:

it was abandoned in shed for 25yrs,

Same as my bike. Right now I’m just proving that it can run before I put too much money in it. 

[Gixer1460]

3 hours ago, RGSX said:

vacuum line was plastic, it doesn't break down, it lost elasticity.

Brake lines were absolutely fine, passed government registration inspection, just as the lines on my 42 yr old bike did. I've since upgraded both rides to SS lines for better braking performance not because there was anything physically wrong with the lines.

If a 'flexible' plastic is no longer flexible - its broken down, UV degradation, call it what you will - its failed.

Re: The highlighted bit above . . . . . that you could see! There are plenty of accidents caused by 'my brakes suddenly failed' ! Would you similarly trust 30, 35 or 40 yr old tyres?

[RGSX]

1 hour ago, Gixer1460 said:

If a 'flexible' plastic is no longer flexible - its broken down, UV degradation, call it what you will - its failed.

Re: The highlighted bit above . . . . . that you could see! There are plenty of accidents caused by 'my brakes suddenly failed' ! Would you similarly trust 30, 35 or 40 yr old tyres?

I could've cut down the plastic and gotten back into the more flexible section and it likely would've been fine but it would've then been too short.

The mechanic who guides my rebuilds has decades of experience as racer, safety consultant, mechanic and crew chief at the highest levels of moto racing, he always seems to be flying off somewhere as a consultant. If he detects something that needs replacing he doesn't hesitate to let me know. I've complete faith in his judgment, he wasn't concerned with my old brake lines when he took the efe on it's 200kph test rides.

[RGSX]

2 hours ago, Apples said:

Same as my bike. Right now I’m just proving that it can run before I put too much money in it. 

if it turns over you can usually get it to run, it just may not run well

My efe came with two broken plugs rusted/fused into the head. $1,200 later I had rebuilt head and it started up on the first attempt...well it did once I learned unlike my other bikes I needed to pull in the clutch first.  Normally $1,200 may have been too much and I should've looked for a running bike but I only paid $1 to make transfer of ownership legal.

[Apples]

1 hour ago, RGSX said:

if it turns over you can usually get it to run, it just may not run well

My efe came with two broken plugs rusted/fused into the head. $1,200 later I had rebuilt head and it started up on the first attempt...well it did once I learned unlike my other bikes I needed to pull in the clutch first.  Normally $1,200 may have been too much and I should've looked for a running bike but I only paid $1 to make transfer of ownership legal.

This bike was given to me from my brothers father in law. It got left in a rental property and all i have is a photocopy of the title. Still not sure how to make it legal but I’ll figure it out. Last time it had tags was 1998 so I’m guessing that’s the last time it ran. I got it to start but not through the tank... I don’t know if I don’t have enough vacuum to open the tap or what. So I improvised. Also, electrical tape does not hold up to gas well. 

[RGSX]

Here all I need was to produce the sale invoice from previous owner. If it was stolen it'll come back when they do a search history.

Water bottle is considerably less expensive than a MotionPro bottle . You now know it starts and it doesn't when you hook up the tank there's a problem with the tap or line leak. My petcock was okay for vacuum but it leaked, I found another at a local salvage shop. You could install a Pingel petcock, just don't forget to turn it off.

[Apples]

1 hour ago, RGSX said:

Here all I need was to produce the sale invoice from previous owner. If it was stolen it'll come back when they do a search history.

Water bottle is considerably less expensive than a MotionPro bottle . You now know it starts and it doesn't when you hook up the tank there's a problem with the tap or line leak. My petcock was okay for vacuum but it leaked, I found another at a local salvage shop. You could install a Pingel petcock, just don't forget to turn it off.

Illinois is terrible when it comes to not having the original title so hopefully the photocopy will help some. I don’t have a problem with forgetting to turn them off, just forgetting to turn them on usually. 

[Reinhoud]

On 9/23/2020 at 9:57 AM, Apples said:

So, I have this 1978 GS1000 that I need a new petcock on. Problem is, none of them look like what I have. I ordered one that said it fits, but it doesn’t. I’m guessing I have a different tank? Any ideas on which petcock to get? 

They're on E-bay

[RickLee]

The cheap Eblag petcock have a diaphragm that is made of much much thinner rubber sheet than the original equipment. The corners of this cheap diaphragm where the 4 screws go.... the screw holes are so close to the edge of the corner that they tear right out under the vacuum of any bike larger than a 650. I got the guy who sold me one to apply a refund.  
 

Im not so sure a GS 750-1000 can run optimally with a straight feed without the vacuum actuated diaphragm. I could be wrong, but I’m going to step up and find the OEM parts.  
 

like a lot on this thread I’m dealing with a bike that had been sitting for god knows how long.  I know it starts and sounds good cuz I was able to do that before the diaphragm popped. I just can’t ride it yet due to dangerous issues like brake restoration, cracked tires, dirty gas tank, loose crap and many other incidentals. 
 

if anyone ever finds a real good replacement petcock that works vacuum Wise like the original for a GS1000 please direct me there. Otherwise original Suzuki rebuild kit and petcock filter replacement ( mine is broken ) ...  Thanks and good luck with these old monsters. They are fun but lots of issues being42 years old and sitting.

[Apples]

On 10/3/2020 at 4:05 PM, RickLee said:

The cheap Eblag petcock have a diaphragm that is made of much much thinner rubber sheet than the original equipment. The corners of this cheap diaphragm where the 4 screws go.... the screw holes are so close to the edge of the corner that they tear right out under the vacuum of any bike larger than a 650. I got the guy who sold me one to apply a refund.  
 

Im not so sure a GS 750-1000 can run optimally with a straight feed without the vacuum actuated diaphragm. I could be wrong, but I’m going to step up and find the OEM parts.  
 

like a lot on this thread I’m dealing with a bike that had been sitting for god knows how long.  I know it starts and sounds good cuz I was able to do that before the diaphragm popped. I just can’t ride it yet due to dangerous issues like brake restoration, cracked tires, dirty gas tank, loose crap and many other incidentals. 
 

if anyone ever finds a real good replacement petcock that works vacuum Wise like the original for a GS1000 please direct me there. Otherwise original Suzuki rebuild kit and petcock filter replacement ( mine is broken ) ...  Thanks and good luck with these old monsters. They are fun but lots of issues being42 years old and sitting.

So, I took a gas tank off of an old riding lawnmower and fed it directly into the carbs that way.  I can get it to run with the engine at full choke right now, but it does run, probably the first time in 20 years.  So far, straight fed is working.  Ill probably just rebuild mine but for right now the lawnmower tank is working.  

[RickLee]

In the past petcocks seemed to be a simple fix.... not so much anymore unless we shell out the bigger bucks.   Below is the picture of an aftermarket petcock that looks promising.  Then another OEM that’s expensive.   The OEM petcock has the feed and vacuum lines on the correct side.   All of the aftermarket I’ve seen have the  feeds on the wrong side. 

[Reinhoud]

On 10/4/2020 at 8:05 AM, RickLee said:

The cheap Eblag petcock have a diaphragm that is made of much much thinner rubber sheet than the original equipment. The corners of this cheap diaphragm where the 4 screws go.... the screw holes are so close to the edge of the corner that they tear right out under the vacuum of any bike larger than a 650. I got the guy who sold me one to apply a refund.  
 

Im not so sure a GS 750-1000 can run optimally with a straight feed without the vacuum actuated diaphragm. I could be wrong, but I’m going to step up and find the OEM parts.  
 

like a lot on this thread I’m dealing with a bike that had been sitting for god knows how long.  I know it starts and sounds good cuz I was able to do that before the diaphragm popped. I just can’t ride it yet due to dangerous issues like brake restoration, cracked tires, dirty gas tank, loose crap and many other incidentals. 
 

if anyone ever finds a real good replacement petcock that works vacuum Wise like the original for a GS1000 please direct me there. Otherwise original Suzuki rebuild kit and petcock filter replacement ( mine is broken ) ...  Thanks and good luck with these old monsters. They are fun but lots of issues being42 years old and sitting.

Why wouldn't it run without the vacuum?

 

I disabled the whole vacuum thing of my GS, works like a normal tap now.