Hate to do this, but I can't find an answer searching the forum.

Was running along the highway about 2 weeks ago and everything was running great!  It started to buck and lost a lot of power at WOT couldnt go above 5000 rpm. Replaced the plugs and fuel filter and seemed to run a little better, but still not right not enough power to climb hills well.  Last night, adjusted the float height to 14mm as I knew I was running rich and took it out for a spin today.  Still running awful.  Runs OK in first and second gear, but very slow acceleration (I think my truck could beat it!! :lol: ) Took a look at the plugs, the right plug is OK, a little wet and gassy but I had the throttle open pretty high.  Pulled the left plug and it was corroded, according to Haynes "overheated".  In fact the exhaust pipe on the left cylinder is turning white   .  

So I am hoping someone can give me some advice on how to fix it, any help would be greatly appreciated.  Thanks in advance.  :dunno:

Don't ride it anymore until you've determined that you have not scored the cylinder and piston on that side, and unfortunatly in order to do that you will need to pull the head (read: topend disassembly in your Haynes manual).

exaust valve shim on that side too thick.

The bike mostly looses power when a demand is put on it?
When ever 1 cylynder is hotter than the other, it means one cyclynder is doing all the work.
Replace if you can the weak cyclynders coil. plug wire, and cap.
This has happened to two of my GS's.

yeah, trouble shoot in order of ease/expense.

Look to make sure that the right (cold) plug is getting spark and that all the electrical components are well connected.

but I think it is most likely a valve issue. do a valve clearance check.

Did a valve clearance check today, the right exhaust valve was at 0.102 mm clearance, the others were all in spec ( >0.03 and <0.08 mm).  So is the exhaust valve too tight and is the problem?  I am a complete noob to valve adjustments so I have been confused by which way is tight and which way is loose.  I also checked spark on both side and it seems to be fine.  Thanks again for all your help, it is greatly appreciated.

The greater the clearance, the looser the valve. So in turn the valve will open less.

OK, switched out the shims today (2.625 to 2.65 mm) and put the valve cover back on. Is there any other tests besides running the bike to see if that corrected the problem?  Thanks as always.

"no no you want smaller shim!!

your clearance is .10xx whatever you said...needs to be up to .3.....Meaning a smaller shim to increase the clearance between the lobe and head...SMALLER SHIM"

edit-woops Noodle head me had things reversed  forget what I said u good to go...What is the exact clearance on the other [left valve]
that .025+ shim just puts you in spec @ .077 [.08 is upper limit]  The closer you can get to the lower limit the better performance will be...See if you can hunt down some shims....