How Do I Know When To Adjust Valves and/or Clean Carbs?

[grandman]

Thanks to the immense resources on this site (and Bike Cliff's) I've been successful at bringing my bike back to life and doing everything from replacing the stator to fixing the fuel sending unit (and many other things). You guys and gals have been great. The bike is running well, but there are still 2 problems that prohibit it from running perfectly: intermittent bogging when the engine is hot and driving at any speed, and an engine clicking/bogging when taking off from an uphill traffic signal under heavy load (me and a passenger). I have no idea if the valves have ever been adjusted, but the carbs were dipped just a few years ago.
What do you think?

[Steve]

OK, so the carbs were "dipped just a few years ago". How has the bike been run since then? If you (or the previous owner) have been riding it somewhat regularly, the carbs are likely still relatively clean. The only time you should need to "dip" the carbs is when they have been sitting with stale gas for a year or more.

Valves? If you don't know, do it now. If you do know, the manuals call for every 4,000 miles. Most times, the valves on an 8-valve engine (the ones with shims) will tighten up. The 16-valve engines usually tighten up, too, but can go either way, depending on whether you tightened the locknut properly. When the valves get too tight, the bike will be hard to start when it's cold, but will start well when it's warm. Other than that, you may never know, so just check them every 4,000, as the book suggests.

.

[grandman]

The bike actually sat with old gas for 3 years beginning just a couple months after carbs were dipped. Would that answer the intermittent bogging? The bike starts almost immediately when hot or cold, but would adjusting the valves stop that low-end chattering I hear when taking off under heavy load?
I guess the next project is cleaning the carbs. Bike Cliff here I come.

[Larry D]

As recommended, adjust your valves and then do them every 4000 after. Sounds to me like your low-end chattering under a load is the lack of twisting your right wrist. Practice giving it a little more throttle under those circumstances.

[Nessism]

The valves can burn if they are not adjusted since they tend to sink into the head until all the clearance is gone - they burn when they can't seat anymore. I strongly advise anyone working on a GS bike with an unknown valve adjustment history to do a proper adjustment before the bike leaves the garage. Once symptoms show up it's too late and damage will have been done.

Regarding the carbs, if all the rubber O-rings were changed within the last few years and the bike has sat alot, running a tank or to with Seafoam inside may take care of the problem. If the O-rings are origionals I'd change them even if the bike seems to run well; the rubber is bound to be hard and brittle so it's just a matter of time before runnng problems show up. It's a simple matter to change the O-rings, particularly if the carbs are clean inside.

[grandman]

Drove the bike home from work tonight and realized it runs really good from about 5k rpms and up. Below that and it sounds like it's running on one less cylinder (very boggy).

[lucabond]

Have you adjusted your carb mixture screws for the highest idle ?

[grandman]

No I have not. Should I start there?

[Don-lo]

A compression test will help to decide where to go first: If compression is good, then the valves are closing, so carbs would be first. Of course, this won't tell you how loose the valves are.

The bike actually sat with old gas for 3 years beginning just a couple months after carbs were dipped.

That kinda wiped out the previous dip, I'm guessin'. It sounds like at the very least some pilot jets are plugged