Was asked to post a few fotos, so here goes....

Always a challenge those holes in a fuel tank. The last one I fixed had 7 holes and then after it was welded I stripped the paint only to reveal a lot of work with the filler.

What Ricks says. A replacement tank might be the least aggravating option.

holes in the tank , pretty typical

Still working on "Kay" and finding things here and there.
Today I thought I'd work on the air filter and see what pops out at me.The white balls are spider egg sacks, there's remnants of a moth in there too. 
Like my previous posts the bike was running up to a year ago, and then started to run a bit rough. Previous owner thought it could be the ignition module. I don't know just yet.
However I have found some things which makes me think it might no be the ignition module. Quite a few of the vacuum hoses are perished and have holes in them. One was taped up, I had the lad squeeze it and you can see the splits. The hose at the back of the butterflies popped off very easily and I was surprised to see this white nipple which I think connects to the air box. The vacuum hose on the back of the fuel (regulator?) would be losing vacuum or allowing the bike to suck in more air.
Anyway I'll keep chipping away and when I think I have it sorted, I'll start all over again. Walking inside to have lunch and saw the Hibiscus flower soaking in the suns rays. I need to get out and soak in sun rays. Preferable out on a nice quite twisty road......ahhhhhhhhhh

yep that certainly would make it run rough down near idle especially

besides being lean up higher

the vacuum line reduces the pressure in the fuel rail when the vacuum is higher ...but still a source for leaking into the system as well
as in all restorations  replace as much rubber as you can .

keep at it

good luck

You're on the right track looking for air leaks and there are bound to be plenty of them.

With all that perished rubber, I hope you didn't pay a lot for the bike.

Point-Seven-five wrote:With all that perished rubber, I hope you didn't pay a lot for the bike.

I paid Aus $500.00 which I thought was ok.

On another matter would this model have an air flow meter and if so where? I cant see anything the resembles one.

There is no AFM on the 16V they rely on throttle opening and air temperature. The Throttle position sensor really does give an accurate reading of the position where the TPS on the 8V only gives idle and wide open with nothing between.

ahh, this is good news, it was doing my head in.

Thanks.

Throttle response with the throttle position sensor is a lot better than with the MAF because the barndoor lag is eliminated.  It is a nice upgrade from the Jetronic on the 2 valve models.

I always get the fuel injectors serviced on any K I buy.  I'd do it for sure on a bike like that because given how all of the rubber bits have decayed I'd suspect that it has sat for some time and that some of the gas in the FIs has turned to varnish.

duck wrote:I always get the fuel injectors serviced on any K I buy.  I'd do it for sure on a bike like that because given how all of the rubber bits have decayed I'd suspect that it has sat for some time and that some of the gas in the FIs has turned to varnish.

Thanks Duck will do. I have just spent the last 30min watching U-tube on how to go about cleaning injectors.
The wife has just left the house so I'm going to "borrow" her jewelry cleaner. It's a little ultra-sonic bath. Not sure what cleaning fluid I should use. (any ideas....anyone)
I was thinking kerosene...... or white fluid.

I did see some videos where they removed some type of filter from inside the injector, look pretty brutal. I'll just see how I go and be extra careful.
It's funny how other videos popped up when watching U-tube, when I finished the injector cleaning, a video of a vibrating parts tumbler came on.......hmmm how cool are these. Ahhhh living behind the black stump sure is a worry, I miss out on a lot, what will they think of next? Automatic motorcycles   nah I cant see that happening.

To get the little filter I clamp a self tapping screw in the vice by the head then screw the injector onto it so it grabs the filter and give it a heave, works great and no damage to the injector.  In the ultrasonic cleaner I use water with dishwasher powder, it's low sudsing so the cleaner doesn't overflow with bubbles.
Use a 9v battery (household smoke alarm) battery to operate the pintle and compressed air to blow it out then put some carb cleaner into the injector and blow it out after 1 minute. DON'T use a 12v battery to keep the pintle open or the coil will overheat and destroy the injector.
If the pintle is stuck use 12volts for short bursts to break it free. If it wont come free tap the end of the pintle needle with a small copper hammer while holding the injector in your hand. Rust is usually the reason the pintle needle sticks so be aware that the injector will wear quickly from then on so plan on replacing them.
A kit to buy for them is the same as for a BMW 318i, the BMW M60 and M62 V8 (2 kits) and the M70 V12 (3 Kits).

I had my tank welded by a guy in slack creek brisbane 

He also pressure test them in a bath of water 
I asked him about how muck pressure he put into them 
He said about 3 PSI other wise you will strech the aluminium tanks 

He said it just enough to show the pin holes 
Th e biggest promble with our tanks are the suck back when welding what ever that means 

I just nodded in agreament not sure if i was the sucker or not but for $200 buck and a dry tank i was happy 

I have a good second tank here it the rear bolt hole type nice a clean no pump ect

Thanks for this tips.

I didn't read the replies until now so I've jumped in and started to dis assemble the injectors. Took the rubbers off (which was harder than I thought it would be) and then placed them into the Ultra-bath....Using mineral turpentine...   

I then made a quick blow through tester and used one of my little 12v 5Amp power supply to open and close the coil...  





I'll try and upload a video onto Utube showing the spray.. Looked ok but.....I'm not 100% whats good or bad.

This might help.
Regards Martin.

I picked up the tank today, dropped it off at the welders yesterday and it looks good.
He welded all the holes and when I was removing the heat shield I noticed some pitting and though get that welded too.
He charged me $40.00 I'm very happy with both.

Regarding the problem of pin holes in these old tanks, I wonder if the easiest solution wouldn't be to line the tank with something like Caswell's epoxy. Or, does the fact that the fuel pump resides within make that impractical?  Has anyone tried tank liners of any sort?

Not all tank liners are the same. A mates bike that at some stage has had a chemical liner added, has the liner now peeling off in places. It is peeling off in good sized flakes and in some places quite easy to peel off. However in some places it has really bonded. We don't know what the liner is but it is a golden brown colour. Just after he got it he had to reseal the lower edge of the tank due to the liner failing. If I had a leaking tank, I would now probably go down welding or aluminium solder route.
Regards Martin.

It goes without saying that there are liners and there are liners.  Also, the prep is super important if you are going to see success.  I've used Caswell's and found it to be excellent, five years on and all is well. If it were to fail, I imagine it would be a very sad day.  Removing the epoxy seems impossible, and if fuel or water has intruded below the epoxy the tank may well be a write-off.

svenok wrote:It's funny how other videos popped up when watching U-tube, when I finished the injector cleaning, a video of a vibrating parts tumbler came on.......hmmm how cool are these.

If that's the one by a guy called Ichabod, he's taking the piss - deviously and deliberately. Avoid any and all of his videos at all costs. Asshole.

Dai wrote:

svenok wrote:It's funny how other videos popped up when watching U-tube, when I finished the injector cleaning, a video of a vibrating parts tumbler came on.......hmmm how cool are these.

If that's the one by a guy called Ichabod, he's taking the piss - deviously and deliberately. Avoid any and all of his videos at all costs. Asshole.

Not sure, these were factory made cleaners. I have started looking at home made ones. I do appreciate the warning, I can see you do not like this man or his videos.
I came to the site to gain knowledge and wisdom, I would be a numpty not to adhere this advice.