Default Shim Sizes (Intake)

[Thorn]

Hi there, anyone know the standard shim sizes?

I know the exhausts are 1.75mm standard, but the haynes manual makes reference to 1.50mm for the intakes yet mine all seem to be 1.85's

Regards,
Thorn

[red98]

Hi there, anyone know the standard shim sizes?

I know the exhausts are 1.75mm standard, but the haynes manual makes reference to 1.50mm for the intakes yet mine all seem to be 1.85's

Regards,
Thorn

every engine will vary........1.75 / 1.85  is about average,its the gap thats important , change the shims to what ever size to get the correct gap 

[unfazed]

No such thing as a default shim size. As red98 stated the most important thing is the clearance/gap.
Shims vary in size from 1.20 to 2.40 in .05 steps.
The original shims are in .01 steps and you could for example find 1.82.or 1.78 in place, whereas the nearest shim you can buy to these sizes would be 1.75. 1.80 or 1.85
This is becuse thay are machined by the factory to get the valve clearance as close as possible to ideal accross all valves.
The Haynes manual show 1.75 as an example not default.

[red98]

just bought some myself,yes yam shims are available in 0.01 steps but are £8 each    patern shims (i bought mine from wemoto) available in 0.5 steps are £3.65 each,your lucky if you get the gap spot on but you will get it well within tolerences using the pattern ones 

[Dead Eye]

Well that explains all the random different numbers on the shims on mine then! By the seems of things, no one had ever checked them but to be fair it was only at 24k so I expect them to still be in spec - I'll be checking myself once he new cam chain goes on and everything is built back up

[unfazed]

just bought some myself,yes yam shims are available in 0.01 steps but are £8 each    patern shims (i bought mine from wemoto) available in 0.5 steps are £3.65 each,your lucky if you get the gap spot on but you will get it well within tolerences using the pattern ones 

I have never been able to get shims in 0.01 increments. As far as I am aware Yamaha do not sell in shims 0.01 increments, where did you get them?

[Thorn]

Thanks for that, I realise they will all vary somewhat but I assumed there would be an "ideal standard", seems not. Head goes on tomorrow so I'll get a chance to check the clearances then, no idea of the mileage on this new head 

[unfazed]

Out of idle curosity why did you have to replace the head???

[red98]

just bought some myself,yes yam shims are available in 0.01 steps but are £8 each    patern shims (i bought mine from wemoto) available in 0.5 steps are £3.65 each,your lucky if you get the gap spot on but you will get it well within tolerences using the pattern ones 

I have never been able to get shims in 0.01 increments. As far as I am aware Yamaha do not sell in shims 0.01 increments, where did you get them?

to be honest i`ve never bought the yam ones and just assumed that if i have odd sizes in the bike already,and i know pattern one only come in 0.5 steps,that yam would sell the 0.1 sizes....will ask next time iam in the yam dealer  [size=78%] [/size]

[red98]

Thanks for that, I realise they will all vary somewhat but I assumed there would be an "ideal standard", seems not. Head goes on tomorrow so I'll get a chance to check the clearances then, no idea of the mileage on this new head 

when you do check the clearences measure all at once , you may be able to swap one shim with another to get the gap right.all mine were slightly out (not much) but with a bit of swapping and changing i only had to buy four new ones 

[Dead Eye]

Oooh that's a good idea - need to remember that for myself as well

[red98]

ah yes...a tight wad tip from a tight wad fazer rider 

[Thorn]

Out of idle curosity why did you have to replace the head???

A new head was substantially cheaper than sorting the six exhaust studs which snapped flush. The old head will be refurbished later on when I have time, then I'll probably flog it on ebay.