Valves n Shims...

[mvalenti]

Well, after much reading about tuning carbs n whatnot, the place to start is the valves and work out from there... So I purchased the tappet tool, and a new gasket. Once that arrives I will start the teardown to figure out what shims I will need. I have no idea what the PO did or didnt do to the bike. I read all the basscliff stuffs, thank you! Good info there. Any other helpful hints the group can lend is much appreciated. For now I have one question.. Where do you folks get your shims?

-Mark

 

[hampshirehog]

Where do you folks get your shims?

From out of my engine.

That's not as stupid as it sounds. If you check all your clearances and know your shim sizes (you will have to find those out as this is your first foray in there) you can usually do a bit of hokey-cokey and shuffle things round and maybe only have to buy one or two new shims.

Z1 seems to be a good place to buy those new shims in the US though.

Or join the GSR shim club.

 

[MisterCinders]

Best tip is to measure all your clearances and check the thickness of your current shims first, and use that to figure out what shims you need. You might find some clearances that are tight and others that are loose, such that you can swap your current shims around to bring some or all of your clearances into spec.

Whatever you do DO NOT TURN THE ENGINE/CAMS WITHOUT A SHIM IN PLACE. If you need to turn the cams to swap shims, pick up a thin spare shim to use as a placeholder to rotate the cams.

Once you know what you need, you can generally pick up individual shims from a local dealer or repair shop. Even if they don't sell them over the counter, a lot of times the shop will let you buy or even trade shims with them.

Failing that, you can order shims from Z1 or trade shims through the shim club on this forum. Look in the Member Service sub-forum for the Shim Club details.

HTH

PS - put your location in your profile. If you are local to other GSR folks, they can help you with shims and/or doing the valves. I have helped at least one member in the Chicago area with that stuff.

 

[7981GS]

Thanks guys.

http://www.thegsresources.com/_forum/showthread.php?t=189085

Eric

 

[mvalenti]

Thanks again all, I appreciate the time you are taking to answer my questions. Will let you know what I find out when I open her up.

 

[mvalenti]

shim tool came in the mail today... now waiting on the gaskets. Just curious, I have a full machine shop at my disposal. Rather than get a temporary shim, I'm thinking I could machine one. Whats the dimensions I should use?

 

[7981GS]

29.50 mm diameter and 2.60 mm thick should get you into the Ballpark.

Eric

 

[hampshirehog]

You can use a coin that's roughly the same size - 2 bob bit works a treat over here but you'll be all dollars and cents and will know better than me how big they are. Needs to be about 29mm diameter and 2mm thick.

 

[daturat100r]

just do them one at a time and there is no need to turn over engine while shim is out,makes it a **** load easier doing one at a time less chance of mistakes /errors recording shim sizes and loading them into spread sheet

 

[Missile99]

just do them one at a time and there is no need to turn over engine while shim is out,makes it a **** load easier doing one at a time less chance of mistakes /errors recording shim sizes and loading them into spread sheet

Agreed. Measure the two adjacent clearances then take one of the shims out. Write the shim size down and measure it. Put it back in and do the adjacent valve shim. Repeat 4 times. Make a chart like this or get a spreadsheet from Steve.

 

[Steve]

Make a chart like this or get a spreadsheet from Steve.

Steve?? Who the heck is "Steve"???

Spreadsheet info is found below.

.

 

[7981GS]

Missile, I like the way you do your specs.
Neater and with less/no oil stains on the sheet.
I just do before and after specs. for each of my bikes and mic them also.

Eric

 

[mvalenti]

Thanks guys, will do. Hopefully I can play the shell...err... shim game. Going to swing by the local auto parts store and rent a compression tester tonight and see where I'm at. If all checks out and compression is fine, would I still want to do the shims? I'm thinking yes....

 

[Guest]

Yes, Check your valve clearances!!! Very often overlooked by previous owner(s). Bad things will occur if they are too tight. Ray

 

[7981GS]

Yes.
Every new to you bike should be treated as a blank chalkboard.
"Nothing has even been done to the bike", should be your plan of attack.

Eric

 

[Missile99]

Steve?? Who the heck is "Steve"???

Spreadsheet info is found below.

.

It's this guy around here with no name. I think he's some kind of GS wizard or something.

Missile, I like the way you do your specs.
Neater and with less/no oil stains on the sheet.
I just do before and after specs. for each of my bikes and mic them also.

Eric

Thanks Eric. Somehow I managed to keep oil away. The bucket tool never slipped.


Ghost, I found the valve check/adjust to be simple and even somewhat enjoyable. :-$ The worst part was cleaning the friggin' gasket surfaces.

 

[mvalenti]

As I read thru the pages of information regarding valves and shims. A question keeps popping up. as the valve wears, it seats deeper/tighter. When you reshim you are adding thickness to fix this problem. Doesnt this now not let the valve seat completely? Or if it gets to this point a new valve is required?

 

[Missile99]

As I read thru the pages of information regarding valves and shims. A question keeps popping up. as the valve wears, it seats deeper/tighter. When you reshim you are adding thickness to fix this problem. Doesnt this now not let the valve seat completely? Or if it gets to this point a new valve is required?

The valves do tighten up, yes. When you adjust your clearances you almost always reduce the shim thickness, allowing the valve to seat completely. If you're at a point where you're putting in a really thin shim, then maybe you would consider doing valves. From what I've read around here, it would take some serious mileage or neglect to get to that point.

 

[mvalenti]

The valves do tighten up, yes. When you adjust your clearances you almost always reduce the shim thickness, allowing the valve to seat completely. If you're at a point where you're putting in a really thin shim, then maybe you would consider doing valves. From what I've read around here, it would take some serious mileage or neglect to get to that point.

the valve wears, the valve stays "open" with the thick shim, and a thinner shim is needed to "close/seat" it propper... OK I think I have it....

Now, what about decarburizing the pistons/heads? Do any of you treat at this point with sprays or additives?

 

[Missile99]

the valve wears, the valve stays "open" with the thick shim, and a thinner shim is needed to "close/seat" it propper... OK I think I have it....

Now, what about decarburizing the pistons/heads? Do any of you treat at this point with sprays or additives?

You said it well. The valve wears in and the thick shim hangs it open, reducing compression. Speaking of which, if when you check your compression the numbers are good then I wouldn't worry about cleaners or additives. The way I clean up carbon is to run to 9500 r's at every shift. That should do it. My $.02. Others here may have a different solution.