Having trouble with valve shim chart and what shim to use

[Old Rider]

So im into adjusting the valves ,but having difficulty understanding what shim i need on some of the valves.
The problem is on my inntake 1 and 2 on cylinder 1. the measured gap is 0.102mm on both and the shims istalled is 272 on both. In the shimchart if i use 270shim installed it says to replace with 265 shim. Dosent that only give me like 0.108 mm ?  can i use a 260 or 255 shim instead?

[FJmonkey]

I just added the shim chart data as posted in the GYSM. http://www.fjowners.com/index.php?topic=16002.0

Read across the top to find the installed shim size. Then read down on the left to the measured gap. The new shim is where the two meet.

Remember to install the shims number side down to preserve the numbers for next time.

If you PM me I can email the Excel copy.

[Old Rider]

Thanks for sharing the chart ,but i have the chart already .The problem im having is that i have 272 shims installed and they not in chart.

[racerrad8]

A 268 would be what you need from a 272 to get you where you need to be. Each half size is .05mm so from .102mm to go down one half size from a 270 to a 265 would make it .152mm which is the correct measured interval range of .11mm-.15mm for the intake side. If you went to a 260 it would be .202mm and a 255 would be .252mm and so on.

A 265 would also work as it would put you a tad bit to the loose side.

Robert

[FJmonkey]

Current gap .102 MM, current shim is 2.72 (272). To get to the MAX gap (loose is better) then you need a 2.672 shim, Nominal gap a 2.682 shim, MIN gap a 2.712 shim. Your choices are a 2.65 or a 2.70. Considering loose is better I would use a 265 and deal with any valve tap that might result. If you go with a 270 then you might want to shorten the time between the next valve check. They tend to tighten over time.

Going from a 272 to a 265 will add .07 MM to your gap, .102 + .07 = .172 (MAX gap is .15). 272 - 270 will add .02 MM, .102 + .02 = .122 (MIN gap is .11).

[racerrad8]

Your choices are a 2.65 or a 2.70

True for some but not for all.

RPM has the genuine Yamaha, in between 2 and 8 sizes in stock Valve Shim

The 268 would make the measurement 0.142mm which is smack dab in the middle of the minimum 0.11mm and maximum 0.15mm.

Robert

[FJmonkey]

I missed that when I checked the web site. I need to update my chart to include these. I will also correct the files section as well. Thanks.

[Old Rider]

Thank you for claryfiing guys its been very helpful I contact the local dealer tomorrow and se what shims they got.Need to get the bike up and running fast as season is short her in Norway