mustering the confidence to do my valve adjustment

[trippivot]

specs ? I think it is about the noise.

I loved immigration canyon when I lived in your area. we did it as long as it was clear - had a ratty old 82 750 GPz those days - yeah DOHC shim under bucket - and Plaza Cycle

you guys are overthinking the valve lash -- the only rule about temperature -- is the engine not operating temp. over 100 degrees hot - I have done it hot - you may get a ticking valve after it cools off -you might be able to hear them more than normal .. you can hear air cooled bikes internal parts moving more than other engines.

the biggest thing is there IS space when valve is closed .. .001" is tighter than spec and very quiet -- .008" is looser than spec and you can hear it especially right at a cold engine start up...

I like to say, "I'd rather hear them than smell them." wide lash and true duration can be debated but the flank of the camshaft and base circle are not perfect either, so don't lose sleep over 0.001" or 2 -unless they are too tight-

[mikerophone]

I loved immigration canyon when I lived in your area. we did it as long as it was clear - had a ratty old 82 750 GPz those days - yeah DOHC shim under bucket - and Plaza Cycle

Love all the canyons around here, especially the ones like Emigration and American Fork that you can loop, no need to turn around. Plaza's still around. Don't go there much these days though.

Funny, just a couple weeks ago I was up in your neck of the woods, passed the Mars Cheese Castle on the west side of the freeway heading from Milwaukee to Chicago...the company I work for buys some specialized CNC cutting equipment from a company in Milwaukee and Franklin and we have offices in Chicago proper and Elk Grove Viilage so I'm out there quite a bit. Will be there all next week too. Small world!

I like to say, "I'd rather hear them than smell them."....so don't lose sleep over 0.001" or 2 -unless they are too tight-

^^ Stated perfectly. Unlike some things, a little loose is better than a little tight.

[growler]

So I finally started this over the weekend. Got everything tied up out of the way, breather cover off, valve cover off without any issues.

However, I am thoroughly confused reading the tutorial and determining which lobes correspond to 1, 2, 3, 4, and should both lobes of one side of engine be pointing the same direction when taking measurements? So if i'm on the right side of the bike (if i was sitting on it), those are 3 and 4 right? When I have lobes pointing forward then I am measuring exhaust of 3 and 4? Ugh. I learn visually so it's hard for me to just read the tutorial and understand. Maybe I'm making this too complicated, but i've read everything and i'm just more frustrated than before.

[JTGS850GL]

Download the manual from here:

http://www.mtsac.edu/~cliff/storage/gs/GS850_Manual_HiRes.pdf

Jump to page 25 and it shows the pictures of how everything should be oriented in figure 3-6.

Start with cylinders 1 & 2. Rotate the crank clockwise until the exhaust cam lobe on #1 is pointing forward and level with the top of the head's gasket surface. The #2 lobe should be pointing almost straight up. At that time you can measure/adjust the clearance on 1 & 2 of the exhaust.

Rotate the cam so that the #1 intake cam lobe is pointing straight up. The #2 lobe should now be pointing back toward the rear of the bike and be level with the rear gasket surface. Now you can measure/adjust 1 & 2 intake valves.

Go to the other side of the bike and rotate the crank so that the 3 and 4 exhaust lobes are in the same position as was on the other side. Measure/adjust 3 & 4 exhaust.

Turn crank until the intake lobes were in the same position on the other side with the #4 lobe pointing up and the #3 lobe pointing back. Now you can measure/adjust 3 & 4 intake.

Done.

[Steve]

Yep, JT has it.

The FACTORY manual explains it properly, Haynes and Clymer only say "position the cams this way to check clearances". Only the factory manual says what JT said, "Position the cams like this, measure BOTH valves on that side of the engine".

.

[growler]

I must be making this way harder than it is. So let's say i'm measuring exhaust clearances of #3 and #4. When #4 is in the correct lobe forward position and ready to be measured, #3 will be in a different position (as in the below photo). When I'm ready to check #3 exhaust do I then turn engine so that the #3 lobe is now forward and then measure that exhaust clearance?

lobes.jpg

[growler]

Or if I make enough turns both the #3 and #4 lobes will line up in the forward pointing position as illustrated in the manual?

[Wingsconsin]

I agree -- valves are part art and part black magic - and I WATCHED when Steve looked after mine when he helped with the top end refresh last year.
I KNOW I have to do it in the near future - and I have done valves on other bikes, but never a shim in a bucket like these.
Always before a lock nut and adjuster screw ... easier in my opinion because there is no math ..but Steve's spreadsheet does the math for you...




Double, double toil and trouble;
Fire burn and caldron bubble.
Fillet of a fenny snake,
In the caldron boil and bake;Eye of newt and toe of frog,
Wool of bat and tongue of dog,
Adder's fork and blind-worm's sting,
Lizard's leg and howlet's wing,
For a charm of powerful trouble,
Like a hell-broth boil and bubble.

[JTGS850GL]

I must be making this way harder than it is. So let's say i'm measuring exhaust clearances of #3 and #4. When #4 is in the correct lobe forward position and ready to be measured, #3 will be in a different position (as in the below photo). When I'm ready to check #3 exhaust do I then turn engine so that the #3 lobe is now forward and then measure that exhaust clearance?

[ATTACH=CONFIG]38735[/ATTACH]

You don't turn the engine. When the #4 is pointing forward you measure both #4 AND #3 in that position. You only turn the engine when moving onto the next pair. Just remember to NEVER turn the engine over while there is no shim in ANY of the shim holders. Some have used a coin as a place holder but I'd just use an extra shim for that.

[growler]

I think I understand. So when #4 is in that forward position, it doesn't matter if the #3 lobe is pointed forward, or up, etc....just measure the clearance? So all that matters overall is the outside lobe positions?

Sorry for my ignorance, just wanna get it right.

[growler]

I'm close to getting it. I know once it clicks I'll be quite embarrassed.

I agree -- valves are part art and part black magic - and I WATCHED when Steve looked after mine when he helped with the top end refresh last year.
I KNOW I have to do it in the near future - and I have done valves on other bikes, but never a shim in a bucket like these.
Always before a lock nut and adjuster screw ... easier in my opinion because there is no math ..but Steve's spreadsheet does the math for you...

[growler]

I also just ordered another feeler gauge set. The smallest on the set I have now is 0.04mm. Grabbed a set off of eBay that has 31 blades, .038mm to .889mm.

[Steve]

Grabbed a set off of eBay that has 31 blades, .038mm to .889mm.

Ignore those metric APPROXIMATIONS, you have a set that goes down to 0.0015".

Just to help you with some reasoning behind the cam lobe positions: you obviously don't want a lobe pushing on a valve when you are trying to measure clearance. With the lobes in the specified positions, not only is that one not pushing on a valve, the one next to it isn't, either. That keeps the cam somewhat centered in the bearing on that side of the engine. You should note that the valve goes down in the head at about a 45 (or so) degree angle, and the two cam lobes are at about 45 degrees to the valves.

Does it make more sense now?

.

[Allie]

Steve's spread sheet is the mystic hoodoo magic that allows me to do my valves. It also serves as a record of the last time my lazy asp last did the valves. Everything else is pretty straightforward and methodical once you get used to it. Well juggling shims around can be a little creative so you order the least amount of shims necessary.

[growler]

Unfortunately, Steve's spreadsheet isn't my issue. The positioning of the lobes is what I need help with.