Kohler CH960 hard start

[BLES]

Neighbor's Kohler CH960-2011 is a hard starter. Acts like too small size of battery, or it needs valves set, but they are hydraulic. Barely cranks over, but always fires and runs. Switched starters with another engine... same thing. Any ideas?
Thanks.
BLES

[38racing]

Bad ground at the chassis?

[bgsengine]

I agree with 38 - voltage drop test, check grounds all the way from engine block to battery terminal.. starter amps draw test may be of some help too - perhaps something was replaced that was not correct for that model-spec (flywheel? starter gear? aftermarket starter of the wrong type or rating? ) .. perhaps a compression test to see if it is in spec (and not excessive, which might indicate a compression release problem, for example..)

[BLES]

Thanks guys.
I did check for tight connections and grounds. Switched the battery cable just in case it was bad.
Starter draw: how much SHOULD it be? I can test but don't know what normal is.
How do I do a voltage drop test?

Compression release: Yes! This is exactly what it acts like. I've seen lots of Briggs mowers needing valves adjusted (negating compression release) and this acts the same. Figured that wouldn't be the issue with hydraulic lifters, but forgot about the release mechanism itself possibly failed.? What SHOULD compression be on these?

[KE4AVB]

Being a Kohler Command there is no compression release.

From Service Manual

COMPRESSION TEST
For Command Twins:
A compression test is best performed on a warm engine. Clean any dirt or debris away from base of spark plug(s)
before removing them. Be sure choke is off , and throttle is wide open during test. Compression should be at least 160
psi and should not vary more than 15% between cylinders.

All other models:
These engines are equipped with an automatic compression release (ACR) mechanism. It is difficult to obtain an
accurate compression reading because of ACR mechanism. As an alternative, use cylinder leakdown test described
below.

Now is an example of doing voltage drop tests.

[bgsengine]

Voltage drop test - has been discussed several times within these forums.. basically take your DVOM, put one probe on engine block (bare ground) and the other probe on Battery negative terminal - and crank engine over - If you see more than a tenth (0.1) of a volt either way (+ or -) maximum of 0.5V , then you have a resistance in the ground circuit (the reading on your meter is how much voltage is being lost - DROPPED - by the high resistance) if you do find high resistance, use the same probe technique from the next ground point (bare ground on frame or engine mounting surface to the battery negative terminal where it bolts to frame.. then from battery ground mounting at frame, to battery negative terminal on B- post, etc - until you see no voltage drop - that'll localize the resistance to the place you had probes connected previously) Same can be done on positive side (B+ to Starter + post and work back through the circuit)

The key is to be checking for stray voltage values while the circuit is under load..

[BLES]

Being a Kohler Command there is no compression release.

From Service Manual

COMPRESSION TEST
For Command Twins:

These engines are equipped with an automatic compression release (ACR) mechanism.

I'm confused....
I think there is a compression release, as noted in the quote from the service manual you referenced. Maybe you meant something else??

You guys are great! Thanks for the suggestions.

[KE4AVB]

You skipped where it said all other models (engines) meaning other than the Command series, like the Courage. Probably I should have edit that out.

COMPRESSION TEST
For Command Twins:
A compression test is best performed on a warm engine. Clean any dirt or debris away from base of spark plug(s)
before removing them. Be sure choke is off , and throttle is wide open during test. Compression should be at least 160
psi and should not vary more than 15% between cylinders.

All other models:
These engines are equipped with an automatic compression release (ACR) mechanism. It is difficult to obtain an
accurate compression reading because of ACR mechanism. As an alternative, use cylinder leakdown test described
below.

[BLES]

My bad!!

Thanks for setting me straight. Raining here and machine is outside so will wait till another day to look at it again. I guess the good news is: the problem is not the compression release!
Thanks agin!

[38racing]

I thinks it starts in section here about voltage drop.
http://web.ncf.ca/da229/smallengine/mtd ... ical-2.pdf