1980 GS550E Electronic ignition .... issue

[tatu]

Ok, there is no prime only on and res.
Can I.work round that ?.tis a standard original.


Where's a 6mm screw when I need one !
Surely not a 10m cycle ....

I'll start now and should find a screwnsomewhere

No prime position?
Then don't cut the pipe!

[ukjules]

Ok not cutting pipe.
What now ?
Do I still block it tank end ?

1) to get going
2) to fix permanently ?

Should I have a different petcock with prime
for these expeditions ?

[tatu]

disconnect it from the tank, do the unflood procedure I explained and swap plugs, see what happens, remember you have only a carbful to accomplish this, if you cant then be prepared to fill the carbs down the tube without using the tank.
TBH I don't think this is it, but it's cheap and easy.
I think you got burnt vlv
But after you've eliminated this you still got the comp test the way I explained

[ukjules]

Ok lets stop a minute.
All we have done is dry the plug and chamber a bit
a d swap the plugs.

If I run engine with tank on no petrol will flow
unless I attach vacuum pipe.

If I run engine without tank on same issue as always !

Do I need a pwtxoxk rebuild kit in the Longh run !

[ukjules]

Ok,
Plugs swapped and dry now
Unflooded procedure done. Plugs were out in sun for 10 mins

Tank off , vacuum not blocked , only carb fuel.

Same issue , plug 2 when cap pulled no effect
On engine where the other 3 almost stall it when removed

[tatu]

ok, from what you say there it's compression. do you block the vacuum tube when you run it with the tank off, with a dry new fresh known working plug?

[ukjules]

I do not block vacuum off when I run withiut tank.
At home I do same with external tank hung from ceiling.
Not blocking off vacuum. Runs fine forever

[tatu]

send me your, phone no.

[ukjules]

If we assume it is compression what does that mean?
Possibilities ?

Valve clearances were spot on when I left.
Head gasket ? Not real leaking ?

[tatu]

you will know if the HG was leaking, from sound or mess. maybe vlvs weren't spot on or chipped a vlv who knows? compression test because that's all that's left.

[ukjules]

Ok pvt sent

[ukjules]

Right on off to get compressoon checked one more time.
Wil advise

[ukjules]

With a lot of help and I mean a lot ... I have got
somewhere.

Update
If I remove vacuum pipe that goes from tank to cyl 2 and put finger
Over tank end the bikes perfectly on 4.
Remove cyl 2.cap proves its working.

So there it is.

Now I have a petcock with only on and res. No prime.
What are the implications of this ?

Will petrol flow ? If vacuum disconnected?
Do I need a new diapraghm on petcock ?
(As if I suck on carb end of vacuum pipe I can pull petrol through ?)

For my long journey do I need a new petcock with prime on it too ?
If so where do I get one ? I'm in Amsterdam.

Or do I just get a pwtcock kit and am will be fine ?
Or do I just strip my one and it will be fine ?

How do I progress ?

[hampshirehog]

A get you home would be to remove the diaphragm from your tap and screw back together, making sure the thing can't leak (you could cut the middle out of the diaprhragm to make a gasket). Plug the tap end and carb end of the vacuum hose connections and fit an inline tap off a lawnmower or similar on the fuel line.

[uk gs nut]

Progress !. Check your engine oil for fuel contamination. And what Hamshire said about an inline fuel tap but I would just plug the vacuum pipe at carb and tap and use inline tap. I will have a look in my parts stash for a tap.