BigT

What, no GS 1000G or 1100G in the UK?

No 750 G model sold over here That's a Japanese model Those are L model forks, probably GS 1000 L at 37 mm The GSX 1100 model forks have a compression adjuster on the bottom, and it appears that the ones in the photo lack the back plastic adjuster

You can upgrade to Tokiko twinpots easily with an adapter plate. Your skinny front tire won't take much more braking force than they can deliver Twinpot upgrade on a skunk -Google that

Which cylinder isn't firing? #2?

Port spacing should be the same. You'll probably have to fab up a rear hanger

Stock, but if you're riding it, upgrade suspension and brakes

If you're tuning your carbs 3-4 times/yr, something is wrong with the carbs, I haven't tuned mine in over 12 years

How did you set the choke lifters? Should be notch down The K&N should make it run lean, not rich What size pilot jets are in it? Where are the fuel and air screws set? Is the low compression cylinder #3? Has the oil level gone up?

What jets are in the carbs? What exhaust are you running?

Check the choke lifters to see if they are all installed the same, with the notch down.

I rode my 78 thou out to a car thing on Saturday, went to leave and no power Checked the fuses, all were intact, swapped out the main fuse, still nothing. Since the fuse box is a known problem, pulled that when I got it home and found this: Signal wire melted at connector. Male part goes to fuse box

As noted above, separate switch for ignition power. Some have just added a wire into the kill switch instead of separate switch

Once the big starter gear face gets hammered a few times, you must replace I let the one on my thou go too long, looked like the 7 dwarfs had at it. It now hangs on my buddys wall of shame

It's the starter clutch, not the starter. Yes, it will get worse. Pull the stator cover and see how much damage you've done There's a mod that spins the starter, then engages the ignition

Standard exhaust also? Go back to stock jet sizes.

Spamwood, I think the problem is that the 33s are just too big for a stock motor. You'd be better off going back to a VM 28 with similar jetting, The 33s are flowing almost 50% more air

Isn't that an anti dive block off plate at the bottom?

I'm a bit confused at how you think it's venting and pressurizing the crank case at the same time I'm with Dezza, run a clear plastic pipe back past the air box and into a catch can (a pill bottle works) As for the oil leaks, those oval O rings are know to deteriorate over the decades. Just wipe it off and keep riding until it's pouring out I run Rotella T synthetic in my 6 operating bikes with no issues at all

It could be that your fuel tap is leaking fuel down the vacuum line into #2, washing out the cylinder

+1 on proper carb cleaning. Blowing air won't get all the passages clean, they need to be disassembled And, new O rings in the carbs

Many here in the States have done the Salty Monk twinpot upgrade https://www.thegsresources.com/_forum/showthread.php?140253-Twinpot-Brake-upgrade-on-78-Skunk I have done it, found you can skid the front tire at 35 mph if you're not careful

http://members.dslextreme.com/users/bikecliff/images/vm_carb_rebuild.pdf

Deep clean the carb bodies, don't just swap parts Make sure all of the passages are clean

The result of Joan Claybrook. a crazed bureaucrat circa 1980. Safety switches and the 85 mph speedometer, because, you don't need to go faster than that, right?