Sunday, September 20, 2015

MAINTENANCE: VIDEO: Checking valve clearances

Here's a video from across the pond of checking valve clearances on a Rotax type 348 powered MT500.

Depending on who you ask, and which way the wind blows you will get exactly 4397 answers as to what proper valve clearance is. The manual says 0.002" (0.05mm) Cold for both intake and exhaust. Lee at ATK says go with 0.004" for break in period, then you should be fine to snug them down to 0.002". If you go to Ron Woods he says 0.005" for racing and 0.004" for routine operation. Whatever the case may be, here is the ATK Service Manual Instructions:

1. Turn fuel Petcock to OFF

2. Remove Fuel Tank

3. Remove decompression cable from cylinder head

4. Fix crankshaft at TDC

5. Remove the six 10 mm hex head bolts retaining the valve covers. Remove the valve covers. (I would do this one at time)

6. Adjusting one valve at a time, loosen the 11 mm hex head lock nut with a box end wrench (spanner) at the top of each valve adjuster

7. Insert the correct size feeler gauge between the valve top and the valve adjuster

8. Tighten the valve adjuster with a straight blade screwdriver until the feeler gauge provides a small amount of resistance when trying to remove

9. Hold the valve adjuster in place with the screw driver while tightening the 11 mm hex head lock nut (Gonna need the spanner again) with the box end wrench

10. Repeat steps 5-8 for remaining valves

11. Reassemble the motorcycle making sure to set the valve cover o-rings properly to prevent any leaks

In the ATK service manual there was no mention of the cam position during this adjustment. You should probably think about hooking the decompression cable back up too. Hope his helps.

No comments:

Post a Comment