Register Members List Member Map Media Calendar Garage Forum Home Mark Forums Read

Go Back > Technical > Performance and Modifications
Forgot info?

Welcome to! You are currently viewing our forums as a guest which gives you limited access to the community. By joining our free community you will have access to great discounts from our sponsors, the ability to post topics, communicate privately with other members, respond to polls, upload content, free email, classifieds, and access many other special features. Registration is fast, simple and absolutely free, join our community!

Register Today!

If you have any problems with the registration process or your account login, please contact us.

Like us on Facebook! Regular shirt GIVEAWAYS and more


Share This Thread: 
Subscribe to this Thread Thread Tools
Old 10-28-2015, 12:45 AM   #1
NemesisX's Avatar
Join Date: Mar 2012
Feedback Rating: (0)
Posts: 5

Experience: 4-8 months

2009 GS500F

shimming valves in GS500

I am doing the shim to cam clearances on my bike. Currently they are:

Left Exhaust .06/275 Right Exhaust .04/275
Left Intake .04/272 Right Intake .04/278

Specs are .03-.08, so they're all in spec. I'm trying to move them to the looser side of things.

Based on the shims available to me I can go either:

Choice 1:
Left Exhaust .06/275 Right Exhaust .07/272
Left Intake .06/270 Right Intake .07/275

Choice 2:
Left Exhaust .09/272 Right Exhaust .09/270
Left Intake .06/270 Right Intake .07/275

From what I've learned, it's best to have the L/R exhaust valves and L/R intake valves matching (if possible), and better to have the exhaust valves (and valves in general) looser than tighter. If that's correct, it looks like choice #2 is best.

I just wanted to confirm with those experienced. This is only the second time I've done valves and the first time on a motorcycle or a shim over bucket valve train. GStwins suggested that choice 2 is the better one, but noted that my current clearances are good because 3 of the 4 match. I was under the impression that it doesn't matter if the intake valve clearance is matched with the exhaust clearance (only that L exhaust = R exhaust and L intake = R intake).

And I can't leave .04 on both intakes because then I would have to leave the 272 in the left intake and couldn't use it for the left exhaust. I can't source any half size shims on short notice, and I'm unwilling to sand/grind.

Opinions? Thanks!
NemesisX is offline   Reply With Quote
Similar Topics
Thread Thread Starter Forum Replies Last Post
Need some valves Thearmyman83 Super Motards 4 07-07-2013 04:43 PM
valves timboslice General Discussion (Moto Related) 1 05-24-2010 10:24 PM
Shimming Needles on my 250 with Thicker Washers viper15 General Discussion (Moto Related) 6 08-06-2008 08:09 AM
Shimming rear shock Alstare_Gixxer How To's and Q & A's 13 04-23-2008 03:52 PM
valves adjusting hat750 How To's and Q & A's 4 03-25-2007 01:39 PM

Thread Tools


All times are GMT -5. The time now is 02:10 AM. is not responsible for the content posted by users.
Privacy Policy