woodlandfarms
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- PowerTrac 1850, Kubota RTV x900
Did you check to make sure the pistons are moving. Kohler is notorious for breaking rods.
More problems on the 425 Kohler CH25
- Thread starter Modrob
- Start date
ponytug
Super Member
Ok, so both pistons move, all the valves move, but you have no compression, which leaves either perhaps timing, or perhaps lack of oil in the top of the pistons due the fuel / oil issue and wear, or no fuel, or no spark.
You could try a teaspoon or two of oil in each spark plug hole, then crank briefly with no plugs, put the plugs in after checking the spark, and see where you are. If that doesn't work, then I think you are on to timing or a lack of fuel, but the starting fluid failure suggests no spark or poor timing to me, if the oil in the pistons isn't effective.
All the best,
Peter
oldnslo
Super Member
Does this engine have a timing belt? I don’t remember what models had the timing belt. If belt could timing have jumped a tooth?
RandyT
Elite Member
That was the Triad TH engine family. Good engines until their weren't
Good thinking Peter…I had wondered before I found the bent push rod, and just after I found gas in the oil, about compression. I had spark on both sides. So when I did the compression test about that time, I thought maybe the mixture had stripped all the years of “use and bad oils” away from the rings. But then I thought, wouldn’t that be both sides? I read about 90psi on the other bank at that point.
I had thought about the oil in the plug port today to see if it made a difference, but didn’t get to it. (I was thinking that after pouring a little in, to try another compression reading. Probably not good for a real result, and I can see where your suggestion would likely give a more positive element.)
MossRoad
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I you have good compression on the one side, the engine should still start and cough, run rough, etc, but it should still start.
So compression test on both cylinders would be the start.
Spark: you see it, but is it strong? Could be coil issues.
If spark is strong, you have good compression, you give it a squirt of starting fluid, and no pop, then it's timing. If it pops on starting fluid, but won't run, it's fuel issue.
One more thing. As I recall, there's some sort of seat or saddle thing under the rockers. Someone once mentioned finding that out of place and it caused a similar issue. So it might be worth pulling each rocker and making sure that little thing is installed correctly. I saw a video and/or pictures of it somewhere but cannot recall.
So compression test on both cylinders would be the start.
Spark: you see it, but is it strong? Could be coil issues.
If spark is strong, you have good compression, you give it a squirt of starting fluid, and no pop, then it's timing. If it pops on starting fluid, but won't run, it's fuel issue.
One more thing. As I recall, there's some sort of seat or saddle thing under the rockers. Someone once mentioned finding that out of place and it caused a similar issue. So it might be worth pulling each rocker and making sure that little thing is installed correctly. I saw a video and/or pictures of it somewhere but cannot recall.
The latest has been: no compression at all—zero—on both cylinders, about three days ago.I haven’t had much time to go into it very much since then with so many other fixes that have popped up
. I’m curious to try Peter’s suggestion with the oil in the cylinder and see if any different result. Maybe then a leak down test?..
My last start attempt was after I’d replaced the pushrod and before the last compression test, starting fluid didn’t do much if anything. Adding a little choke as well didn’t help and got that terribly loud backfire—this one sounded like a gunshot! (Scared the crap out of me, and I was ready for it
) The spark tester is inline and appears to be bright. But, this is that ignition system that I believe or calls for the conversion kit of flywheel and new coils. It has that little electronic box mounted over off one of the valve covers…Smart Advance maybe? Wouldn’t it be kind of odd for that system to suddenly go haywire at this point?
I’ll relook at those rockers and see about any seat or saddle…
ponytug
Super Member
Do you have the service manual?The latest has been: no compression at all—zero—on both cylinders, about three days ago.I haven’t had much time to go into it very much since then with so many other fixes that have popped up
I’m curious to try Peter’s suggestion with the oil in the cylinder and see if any different result. Maybe then a leak down test?..
My last start attempt was after I’d replaced the pushrod and before the last compression test, starting fluid didn’t do much if anything. Adding a little choke as well didn’t help and got that terribly loud backfire—this one sounded like a gunshot! (Scared the crap out of me, and I was ready for it
The spark tester is inline and appears to be bright. But, this is that ignition system that I believe or calls for the conversion kit of flywheel and new coils. It has that little electronic box mounted over off one of the valve covers…Smart Advance maybe? Wouldn’t it be kind of odd for that system to suddenly go haywire at this point?
I’ll relook at those rockers and see about any seat or saddle…
Here is Kohler's list;
Engine Cranks But Will Not Start
● Battery connected backwards.
● Blown fuse.
● Carburetor solenoid malfunction.
● Choke not closing.
● Clogged fuel line or fuel filter.
● Diode in wiring harness failed in open circuit mode.
● DSAI or DSAM malfunction.
● Empty fuel tank.
● Faulty electronic control unit.
● Faulty ignition coil(s).
● Faulty spark plug(s).
● Fuel pump malfunction-vacuum hose clogged or leaking.
● Fuel shut-off valve closed.
● Ignition module(s) faulty or improperly gapped.
● Insufficient voltage to electronic control unit.
● Interlock switch is engaged or faulty.
● Key switch or kill switch in OFF position.
● Low oil level.
● Quality of fuel (dirt, water, stale, mixture).
● SMART-SPARKTM malfunction.
● Spark plug lead(s) disconnected.
I would certainly consider the low oil sensor as being possibly bad.
A large backfire certainly makes me think of timing issues. As your engine is a gear driven camshaft, a bent push rod could have done some damage. Did you find any metal when you drained the oil?
All the best,
Peter
Thanks for that link…
I’m just baffled by the sudden loss of compression on both sides. My warped sense of “thinking” can’t get unwrapped on that. Seems like it should be so simple to find but yet I’m fumbling my way around. (I think my biggest problem is I have too many problem projects that need fixed immediately and I keep getting distracted—even my therapist agrees LOL)