79 GS1000E Engine questions

[tatu]

Re carb balancing: On my last rebuild I could only borrow the old original suzuki ball type vacuum gauges and these were very old and in a bit of a state, consequently I failed. However, As it had new rings, reground and shimmed valves I know the engine to be in good nick.
I pulled the carbs wound off the throttle idle so that the slides were full down and with the fuel vacuum pipe blocked and tops off, adjusted the slides up to a small open clearance and then blew through the stub of the carb gently winding the slide adjuster screw down till the throttle sealed, I did this till all sealed, locked up the screws tops on and back on. For me it worked and it runs perfectly.
Unorthadox, deffinatly, and there are other factors to consider (state of valves, rings, ect) Big T's guide as to screws position is the right place to start.
Your dealer is entirely correct in not doing off the bike.
This is only to give you a place to start from.
The only way to know if the head is warped is to take it off and check it.
Timing the valves are done when the 1-4 tdc marks line up in the window (Not the 'F' mark) and the cam lobe marks align with the head.
Have you checked your points and ignition timing?
None of these things will give you a buzzing sound.

[mike_of_bbg]

A proper sync can only be done with a running engine and carbs on. It's not uncommon to do a "bench sync" with the carbs off; usually by getting the throttle plates barely open and using a feeler of some sort or light source to ensure initial even openings of the throttle plates. That's done so that, when it's time to sync for real, the carbs are not so far out of whack that a vacuum sync can't be done easily.

Sync should be done AFTER you check/adjust your valve clearances. The clearances affect the "breathing" capacity of each cylinder.

Quite frankly, I find it very very unlikely that carb synchronization is your issue. Carbs going out of sync is a gradual process over time, not normally a sudden event which corresponds with unusual noises and catastrophic loss of power requiring one to "limp home". Sync-ing your carbs is a fine idea, after they're tuned and all other engine issues have been sorted out.

A valid compression test is a good start. Of course you're holding a questionable tool, and that won't do. IIRC, Snap-On's warranty is basically just like Craftsman's in that once you escape the realm of standard hand tools you're looking at 1 year. If you have a Snap-on dealer near you go to them and see what they can do. Maybe it is just a bad Schrader valve and you can fix it for $1. Some parts shops will loan tools, so check with them to see if they can loan you a compression tester. Borrow one from a friend, or just buy one (what, ~$20?). If there's an HFT near you they sell one for $10.

You can also try out your current compression tester on something else to see if it will give a reasonable result. Maybe the tester is not THAT bad, but your motor is!

What kind of head gasket did you use? Was it an OEM Suzuki? MLS or standard? Did you have to install the corner crush washers and rectangular o-ring for the cam chain tube? Did you re-torque the head after the first few runs after replacing the gasket? Weeping oil from the head gaskets is unfortunately common, and not necessarily a sign of a blown head gasket. Though it seems that once they start weeping oil that replacement is the only option.

You said you checked the timing - is that ignition or cam timing? I could easily see a cam chain coming loose and skipping teeth. The loose chain would cause buzzing. The timing impact of the skipped teeth could definitely cause loss of compression and power.