Should I check my valves?

[Guest]

I'm in a dilemma of impatience. I'm restoring a 79' GS850 with 20,000 that been sitting for four years. My buddy that has worked on bikes for years and whom I share a garage with is trying to talk me out of messing around with the valves in fear of opening up a whole can of worms that don't need to be open, but everything I've read on this forum has told me otherwise.

If I have incredibly good reason to believe that this bike has barely been messed around with, is there a reason for me to check them out? He fears that by opening my the valve cover, I'll need to get a new gasket (becuase of damage from opening it in the first place[?]), engine bolts, and just altogether spend a bunch of money for nothing.

Also, if you really do think I should tear into it while I have the bike in piece (about to finish the carbs and airbox soon) which feeler set do I need? There are so many of them.

I'm incredibly inexperienced with it comes to motorcycles and you guys seem more experienced than him. Any advice would be helpful. Thanks!

[tkent02]

Valves usually get tighter as they wear. Valves burn up when they are too tight. No brainer. Do the maintenance. Yes you will need a gasket. Yes you will have to clean off the old gasket. All much easier than replacing burnt valves.

[azr]

You bought a 79' GS850. Checking the valves is routine maintenance. If I remember right the factory says this must be done every 6000 miles. It's like changing the oil in your car. Sure you can leave it.. but why would you, unless you don't care about your car. Your buddy that has "worked on bikes for years" obviously hasn't worked on an older bike that requires checking the valves or he never would have given you that advice. Just remember when you shim the valves you will need to vacuum synch the carbs afterwards as well then fine tune the fuel and air mixture screws. It's not rocket science, just routine maintenance and very small amount of searching on the site will tell you everything you need to know...that or read through Bikecliffs website.

[Steve]

If I remember right the factory says this must be done every 6000 miles.

Not quite, but close.

It's actually 4000 miles, which is about 6000 kilometers.

Here it is, straight from the factory manual:


.

[giganticflying]

Can I use this set of feeler gauges? The manual says .03 - .08 mm, and this goes from .0015-inch (.038mm) to .025-inch (.635mm).

http://www.amazon.com/25025-26-Blade-Master-Feeler-Gauge/dp/B000BYGIR4/ref=pd_sim_sg_3

or should I go with this slightly more expensive guy?

Blade thickness: 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.15, 0.20, 0.25, 0.30, 0.40, 0.50, 0.75, 1.00mm

http://www.amazon.com/Amico-Metric-Thickness-Feeler-0-02-1-00mm/dp/B0052IRYVS/ref=sr_1_fkmr0_3?ie=UTF8&qid=1381902551&sr=8-3-fkmr0&keywords=feeler+gauge+metric+gs850

[cowboyup3371]

The inch ones will do okay but they metric approximations so you'll have to really pay attention to them. I have the metric ones though and don't have any issues.

Send an email to Steve (the one who posted before you) and get his spreadsheet - it will be very useful to you

[Steve]

Send an email to Steve (the one who posted before you) and get his spreadsheet - it will be very useful to you

Me?
. . . . . .Spreadsheet?

. . . . . . . . . . . . . . . . .Yeah!
. . . . . . . . . . . . . . . . . . . . . . . . . .Look down there.

.

[koolaid_kid]

Get the metric one and be done with it.

[salty_monk]

I would buy the metric feelers (order off the internet if necessary) & the Suzuki Tool for popping the shims out ($14). Some people use the Cable tie through the plug hole method but that's not for me....

When you open it up Pop each shim out in turn to find out what size you have in there and record it as it will really help you next time to know exactly what you have as you'll be able to order what you are likely to need ahead of time.

If you set them near top tolerance you will find that you can actually go much more than 4,000 miles without checking them, if you need to swap shims much more than every 15k then likely something else is wrong..... That's my 2p in any case. Now I have checked my Skunk a couple of times & am sure it is wearing in the normal way & set them all on top tolerance (using "sized" shims from the Shim club) I will likely go 12-15k before I check them again.

[bwringer]

FWIW, tight valves are the reason so many bikes got parked at 15,000 - 20,000 miles. The bike slowly starts running worse and worse, it gets more and more frustrating to start, the owner at the time thinks valve checks are scary or doesn't want to pay the shop, and then one day the battery dies before the thing will start. The bike gets pushed to the back of the garage for 30 years.

So yes, you absolutely must check the valve clearances when resurrecting a GS. It's really not that big a deal, either. Yes, you'll need to buy a new OEM valve cover gasket (don't fart around with imitations), but if you coat it with a thin layer of grease, you'll be able to re-use it several times.

I would also go ahead and get the metric feelers -- the correct valve clearances for an 8 valve GS are TINY compared to many vehicles, and the last thing you need is the potential confusion of inch gauges. Yes, it's certainly possible to use inch gauges if you're organized, but it's another potential source of error you can easily eliminate.

Also, I'm sure there are some friendly GS-ers in your area who would be happy to assist and might even have a shim tool and a shim collection. Post up an "valve check help needed in Portland" thread and I bet someone will pop out of the woodwork.

[Big T]

I have a shim collection, but my tool wandered off somewhere

Give your buddy a dope slap, as he's not as smart as he (and you) thinks he is

I'm willing to bet most of your valves are too tight

Why don't you go over to Harbor Freight and just buy a feeler gauge?

[Gorminrider]

goto local motorcyle shops too. I don't have shims in my bike but my local "goto" shop (because he works on olderbikes) has shims to swap.

[Larry D]

Check the valves and adjust as needed. You and your bike will be much happier. Keeping the valves in proper spec is one of the baselines that will keep your bike running great for many miles.

Have you been to Cliff's site ?

http://members.dslextreme.com/users/bikecliff/

Here's the tutorial for 8 valve engines.

http://members.dslextreme.com/users/bikecliff/images/gs850valve_adjust.pdf

[eil]

Get the second set of feelers that you linked to. It's rare to find a set of metric feelers in the proper sizes in a tool store in the U.S. BTW, you can get them on eBay for $4 each, but you have a wait a couple of weeks for shipping. I have them and they are accurate and work great.

[giganticflying]

Awesome, thanks guys. ordering the stuff today.