Topic: clearance between valves and valves' guide

[_mark]

Hi everybody.
I'm checking on a 750 K1 the clearance between valves and valves' guide.
The manual reports to use a small dial gage and stay within limits. Procedure is quite difficoult because the stem is small and circular leading this to make errors of measurment due to shape, the pointer of dial gage slides because is small etc...
Is there a thumb rule to understand if the valves or their guides are to be serviced ?

Thanks and Regards.

[bryanj]

If you feel a VERY small amount of movement its probably ok

[_mark]

If you feel a VERY small amount of movement its probably ok

yes, the problem is too feel how  much is very small by hand only. 
I have not absolutely experience on this. I can t distinguish 0.02mm from 0.2 mm.

[aircraftgrade]

Another method of measuring valve guide clearance to the valve is to measure the following:

1. The outer diameter (OD) of the valve stem
2. The inner diameter (ID) of the valve guide

Then subtract these two numbers to obtain the valve clearance.

Such as this:

Your rebuild manual calls out clearance via the dial gauge method. Those values are slightly different, since the angular movement of the stem inside the guide will be different than the actual clearance of the stem and guide. I would try your best to obtain the numbers via the method they have given you, but if it isn't working this is another method to try.

[grcamna2]

Another method of measuring valve guide clearance to the valve is to measure the following:

1. The outer diameter (OD) of the valve stem
2. The inner diameter (ID) of the valve guide

Then subtract these two numbers to obtain the valve clearance.

Such as this:

Your rebuild manual calls out clearance via the dial gauge method. Those values are slightly different, since the angular movement of the stem inside the guide will be different than the actual clearance of the stem and guide. I would try your best to obtain the numbers via the method they have given you, but if it isn't working this is another method to try.

Excellent 

[754]

Generally the exhaust guides wear faster than intakes.  So there is a fair chance intakes are good.
 So if the exhaust have twice as much wiggle as the intake, they are worn.
 BTW measuring with a dial indicator is not real difficult. If it's a problem for you a lot of the rest of the motor will be as well..