Kohler Courage 20 (SV601) - Valve Adjustment Problem Help

Tried to do my first-ever valve adjustment on my Kohler Courage 20 SV601 engine today following this guide https://youtu.be/VyPCBqGMYvo?t=354, and wound up backing out of the attempt when I was unable to loosen the T15 Torx screw on the exhaust side. As I understood the video, the Torx on the end of the rocker arm stud acts as a jam nut and the 10mm nut on the stud performs the actual adjustment.

I'd rotated the engine until the piston was at the top of its travel (TDC?), but don't know if that was the compression stroke or not. Only the leftmost valve (exhaust, I think) seemed to need adjustment so the first thing I did was to try to loosen the T15 Torx on that side, but the Torx was in so tightly that I wound up slightly twisting my Torx bit trying to break it loose.

So that's where I am at the moment. Any thoughts on how I should proceed or what I might be doing wrong? My Torx driver is a cheap one... should I buy a higher quality driver and try it again? Or maybe find a Torx bit for my ratchet so I can get a little more leverage? Or maybe use a Torx bit in an impact driver instead of a using a screwdriver-type Torx driver?

I should loosen the Torx before trying to use the nut to adjust the clearance, right? That Torx screw is a standard, left-to-loosen thread, right?

I'd really appreciate any tips you guys can offer me.

I use a good Toro bit along with a 1/4” socket on my 1/4” ratchet when adjusting valves and yes they can be tight. You must loosen this Allen screw before adjusting the adjusting nut. DO NOT use an impact driver. This manual might be of some help. http://www.kohlerengines.com/engines/onlinecatalog/pdf/sm_20_690_01.pdf

Same here.
Irwin impact bits is a 1/4" socket on a 1/4" ratchet
I think they come in packs of 4 or 6.
Same story for the T 45 Briggs use on the blower housing.

Thanks much. I've ordered a couple of Irwin Impact Performance Series T15 bits (didn't find a four-pack) and will give this another go when they get here. I had no idea what to look for in a bit, so I was glad to have a specific reference - thanks bertsmobile1. Rivets, that service manual will really come in handy, thank you.

The stuff you buy in the 200,000,000 bits kits are junk
Always to buy just the ones you need and get quality.
Most of the cost is in the packaging and transport so a 4 pack is only twice the price of a single

cmayo said:

I'd rotated the engine until the piston was at the top of its travel (TDC?), but don't know if that was the compression stroke or not.

Click to expand...

It is imperative, if you're going to use the TDC method, that you determine the correct TDC.

There is an easier way--EOIC--which stands for Exhaust Opening, Intake Closing.

With the valve cover off, rotate the crank in its normal running direction until the exhaust valve begins to open. Set the clearance on the INTAKE valve.

Continue rotating the crank in the same direction until the intake valve has just finished closing. Set the clearance on the EXHAUST valve.

This method sets the valve clearance when the cam follower is at the ideal place--directly opposite the peak of the cam lobe. Plus, you don't have to mess with finding TDC.

cpurvis said:

It is imperative, if you're going to use the TDC method, that you determine the correct TDC.

There is an easier way--EOIC--which stands for Exhaust Opening, Intake Closing.

Click to expand...

Thanks cpurvis! I'll give EOIC a try when I get back in there.