Kohler CV20 (1998) No Spark - part spliced between kill wire & ground (need ID)

[DC1998]

Update: I now have spark (using a spark tester), but now my battery is apparently too old to turn the engine over fast enough to start. I recharged it, but it started raining, so I sharpened the blades. I had the battery charger off only during the blade sharpening and just reconnecting the battery charger, it appears the battery lost power as the smart charged started re-conditioning the battery again. So, I'll get a new battery and make hopefully only 1 more update.

Question: Should I continue to use the spark plug gap (0.040") as my dealer recommended for my CV20? My dealer told me to use the spark plug gap for the CV22 for my CV20. It is one of the few (maybe only one) riding lawn mowers that has a recommended spark plug gap of 0.040 " (about 1 mm) instead of 0.025"or 0.030".

Over the last month, I initially had trouble with the starter, (had been getting worse for many years), so I changed the starter/solenoid when I could get the starter to start at all.. That worked fine after I installed it. When I couldn't get spark, one of my gas tanks (right one) apparently developed a hole where the main wire harness was routed.. My seat switch had been de-activated a few months after I got it as the engine was cutting off every time I hit a bump. Since I couldn't find any other switches (didn't know about the tilt switch) as it was not mentioned in the owner manual, I figured it had to be the coils, so I ordered 2, because the starter was working fine.. (In hindshight. I think it was just the mercury tilt switch that I had re-attached improperly after bolting on the starter-solenoid, that prevented my spark.).

Thanks again, especially for the added info on comparison between the CV20 and CV22.

Mark

 

[StarTech]

I kinda about the 0.040" gap as the service manual has it at 0.030.

 

[ILENGINE]

Sometime along the line the spark gap has been updated to .030, because at one time the gap was .040 which was odd, and I think most people tended to ignore anyway.

 

[StarTech]

Sometime along the line the spark gap has been updated to .030, because at one time the gap was .040 which was odd, and I think most people tended to ignore anyway.

The service manual could always be wrong too. But as you said 0.040 does sound odd; unless, I working an automobile engine.

I just got kicked in the tuss by a 2015 JD repair manual that was updated a year later after I brought my copy, current manual was publish in 2020. It cost me $200 and a week delay while waited for the tool that didn't work. Now I got a tool that I probably never use and then I may need it tomorrow.

It is good that most my manuals are PDFs so I add readable notes about changes or about how something is done differently.

 

[ILENGINE]

The owners manual and the service manual both show .030 for spark gap. But remember talking about the .040 used on command engines back when I went to the Kohler dealer school over 20 years ago. And it came up in several updates over the years. I did notice that the .030 in the OM and the SM are both highlighted which could indicate a change.

 

[DC1998]

It was both my local dealer ( the guy who sold it to me and delivered it to me) and the Dixie Chopper Owner's manual (from 1997) that stated 0.040" for the CV22 (I have CV20), but like you, I have not seen this recommendation in any of the Kohler owner's manuals.

I thought I was home free, once I had spark.

Bad News!
I still can't start engine after getting spark (verified by using a spark tester on both cylinders on actual spark plugs). I verified it several times, because I couldn't believe the engine was not starting.
I also sprayed carb cleaner down throat of air intake past choke plate to try to get it started and it hasn't even gotten close to starting, not even for a millisecond.
(For many years, I have had to spray the carb cleaner to start the engine, if it hasn't been used for a few weeks and it has worked.)

I regapped the plugs (new Champion plugs) to 0.030" and still no start, regardless of whether spark testers are in place or not.)

I also checked the compression and have 160-165 psi in both cylinders. Obviously, my engine is cold as i have not been able to start it (last time was in early May, this year).. (Kohler manual states it should be 160 psi if the engine does not have ACR, automatic compression release).

Could I be having too much gas (making it less gas vapor)? (I did clean the carburetor by spraying carb cleaner in all of the ports I saw) I see a thin film of gas just before the carb (at in the bottom of the air cleaner) after attempting to start the engine.

When I have removed the plugs many times over the last few days, I don't notice them being wet at all. They are clean like new and dry.

The items that have been replaced over the last month:
starter/solenoid
gas filter
both coils (set using business card that measured at about 0.011") because I didn't get spark after orienting the mercury switch improperly (maybe I should put the original coils back in, because the spark may not be as strong????)
spark plugs (Champion RC12YC) now gapped to 0.030"

I have had this mower for 23 years (using 0.040") and it always started eventually if I used carb cleaner & battery charger/starter.

I'm very stumped.

My next thought is to either clean the carburetor and rebuild it with a rebuild kit (It is a Nikki carb) or get a new carburetor in order to make sure I don't have too much liquid gas.
Or maybe I should put the original coils back in. Maybe the new coils are not giving me a strong enough spark. Is that possible, even though I have verified that I do have spark??

Mark

 

[StarTech]

Disconnect the gas line and drain the carburetor. Then try cranking and adding a little into carb throat. IF still it still don't start it might ignition timing issue so check the flywheel key. Just a couple thoughts.

 

[DC1998]

StarTech,

I disconnected the fuel lines and tried to start it a few times to make sure I wasn't seeing any liquid as I saw before when everything was connected. I added some carb cleaner as I normally do to get the mower started (at least since 1999) and it never even came close to starting. I even waited to the next day (today) and still nothing. I used my battery and a car jumper/starter (100 A) and the engine was turning fast but there it never started.

So, I thought your idea about the timing of the spark is probably the issue. However, I removed the flywheel and the key looks (after I removed all of the dirt), brand new and it is 23 years old (see photo). There was lot of dirt around and so I cleaned it, rinsed it, and dried it all off. Tomorrow, I will try to put it back together and decrease the gap for the coils form 0.011" to 0.008". The spark plugs I put in look completely unaffected by all of my attempts to start the mower, so there has been absolutely nothing close to any combustion going on. I even checked the orientation of the magnet relative to coils when the piston was at TDC. The magnet has just passed the coil (see photo), meaning the spark took place a little before TDC, which seems correct. I checked both cylinders.

if lowering the gap of the present aftermarket coils doesn't work, I guess I'll try putting the original coils back in. I replaced them when I wasn't getting spark (due to me not realzing that the black cylinder was a tilt swith). Is it possible that the new aftermarket coils aren't putting out the spark magnitude needed even though I'm definitely see spark on both cylinders????
(I definitely see spark, so, it would seem like they are OK, but I don't know of much else to change. except another battery. I thought spark was like being pregnant. It's all or none.)

Is there anything I should do before putting the flywheel back in place?

If you need photos of anything to help me, please let me know.

Thank You for all of your advice up to this point.

Mark

 

[Scrubcadet10]

have you tried flipping the coil over?

 

[DC1998]

The 2 coils are opposite to one another as were the original coils, so that the spark plug lead is on the outer end of the coil (see photo of original coils).
To have the spark plug leads in same orientation, the kill tabs on the new coils are upside down, relative to that of the original coils, but if I were to flip the coils so that the kill tabs were in same orientation as the original coils, the spark plug leads would be farther away from the plugs and I'm not sure It could even connect them. I did consider that possibility but did not that as I thought the spark plug lead orientation was more important than the kill tab oreintation. Original coils had longer leads for the plugs so I could have easily done what you suggested. My older printed Kohler manual states that spark plug leads should be on the ends of the koils (as were my original, but the newer online Kohler manual does state that the kill leads should be on top for engines without the SAM module (My engine does not have the SAM module.)

The magnets on the flywheel easily hold up a screwdriver (I checked it as I did see someone asking if a screwdriver isn't held up, are the magnets still OK.)

Observations:
1. engine is cranking seemingly fast enough with help of charger/starter (plugged into AC in garage), so could the battery power still be suspect in starting engine?
2. I see spark plugs (with spark plug tester inline on both cylinders), so could spark still not be of proper magnitude.
3. When I had fuel connected to engine, I see the bottom of the air cleaner (near choke plate) with a film of liquid (gas) and I have always used carb cleaner (last 22 years on this mower) to add somthing combustable into engine to get engine to start after mower hasn't been used for a few weeks, so could fuel not be of sufficient magnitude to start engine? (or do I need actual starter fluid?)
4. compression test showed 160-165 psi in both cylinders (tested twice). Kohler manual states engine should have 160 psi as minimum, so am I slighlty deficient in compression for MY engine to actually start it?

What am I missing? (ability of engine to actually start, lol)

As someone said earlier in the thread, there is an Oil Switch (Oil Sentry) on this engine (I finally found it on the rear of the engine below the carb) and it is connected to the green wire in the harness, but the green wire from the harness never connects to anything, so it can't stop engine or energize a warning signal. Besides, I am getting spark.

Options:
1. Narrow the gap for the coils to 0.008" (I had it at 0.011") - My older printed Kohler manual states 0.008-0.012" (Newer online Kohler manuals state 0.011-0.013)
2. Get Brand New battery
3. Use actual Starter Fluid instead of carb cleaner when trying to start engine (even though carb cleaner has always worked for me in the past)
- Rebuild carb if Stater Fluid stars engine
4. If all of the above fail, replace the NEW aftermarket coilds with the original coils

Thanks,
Mark