GS550ET 1980 (UK) ticking noise near tank ?

[ukjules]

I have been asking questions in another post about a ticking noise that
i heard at the top of my engine but it seemed to be coming from the tank.
Impossible I assumed coming from the tank - but read on.

the bottom line is I had done a head rebuild, fitted a new cylinder, head, cams,
lapped valves ...... and I heard a ticking noise at the top of the engine near the tank.

It was audible when going along the road. like a small screwdriver tapping on the tank.
It did not interfere with driving though - the bike still goes.

I looked at coil issues, wiring shorting (only briefly as i am not good on electrics)

To cut a long story short , i had the tank off, a 1m pipe connecting the petrol and a 1m pipe connecting the vacuum
to carbs.

I listened to the tank (seemingly crazily) but there was the tapping - in the tank.
I rechecked the frame, engine and no ticking.
Also If i took of the vacuum pipe - it disappeared.
Trust me this sound could have been the valves out - it sounded so similar.

So there we are - the noise is in the tank , petcock or tank cap.
I ran the bike with the tank cap off and no change.

I took the petcock off, cleaned it out and blew out with compressed air (diving cylinder)
and there was a lot of dirt in it.
Also there is a disc and it is broken in half. see attached photo.

I have cleaned it out and put it back together with the broken half still in
as it is in securely.
I started the bike and i think the ticking has gone.
I will confirm today.

Can you get a petcock kit ? i cant find any details with that disk ?
thoughts as always be appreciated.
Bike almost done too ...

[hampshirehog]

Plenty of kits around - take a look at ebay for example. Many people on here will suggest not bothering with the kits and buying a whole new tap instead. I've had no problems with the kits but others have so I guess there's a chance to take.

[ukjules]

Here is the issue - i seem to have a broken disk in the petcock ? there are
no kits that seem to come with this disk ?

disk seems to be metal.
I don't suppose you have an exploded view of this petcock do you ?
The parts online do not show it.

CAN YOU TELL ME IF THE DISC IS ON THE OTHER SIDE OF THE EBAY ONES IN PHOTOS ?

[ukjules]

please dont forget this thread - soemthing so simple is holding up the bike
returning to perfection.

Having never stripped down a petcock i simply dont know if the £13 from ebay
kit has the right bit ?
does that sq diaghpram have a metal disc on the back ?
not a single picture from these people has the reverse side so i cannot see what i am ordering.
see my picture.

[hampshirehog]

That metal disc is attached to the diaphragm and the whole is part of the kit. Make sure that you get the right kit as there are a few different types depending on the tap (don't rely on the year as Suzuki took a parts bin approach) - you'll probably have to ask the seller for measurements as many of them won't know the differences.

[ukjules]

thanks will order.

p.s the who at Glastonbury festival on tv - nothing better ! other than being there.

[ukjules]

Parts arrived and exactly as you foretold they were the wrong parts as I was too late
informing them the exact measurements.
I stupidly assumed giving them the details og bike they would arrive ok.

40mm approx sq diaphragm I need and they sent 35mm sq.

Damned annoying - especially as i used ebay and have to return ......................

[ukjules]

Found proper part at local bike brakers , new stock part. It seems that the diapraghm must make a perfect seal or that tapping starts. The bottom line is with a new one , tightened so not leaking I now have no ticking noise audible while riding. You can hear it if you put your ear to the tank . Does every old GS have this ticking if you put your ear to tank ? Can someone try and report ? " go on , go outside and say I am not going to take this anymore " while listening for tapping ?