[schreib]

OOOooh, that bad feeling in my gut just happened 2 days ago. I was just finishing up cutting the grass at full throttle and was heading to the shed when she stuttered, then started to die. . . I turned off the deck blades and idled down but it barely made it downhill to the shed. Since I had not cleaned it much in the last 3 weeks and sprayed out all the dust and grass I was hoping, somehow, the air filter was so plugged it was choking the engine. Nope. Left it a couple of hours checked air filter, coolant, and oil and all were fine-- oil was down in the low end and needs a bit added. It started OK but faltered. It basically cannot make RPM's and power. No sound is obviously indicating a noise / point of failure, just backfiring a bit, not continuous.

22HP Kawasaki engine, oil is one yr old. It has 850 hrs on it but not sure the engine hr meter is working, bought it used 2 yrs ago. It has run fine since. Today I removed the two plugs and it appears LEFT cylinder is AWOL. Both are wet, not pretty but LEFT is simply black and oily. After re-installing the plugs it worked fine with no stuttering long enough to move it 20 ft. Figure maybe it is only the coil pack? Maybe the backfire is due to occasional compression firing of some sort?

Maybe I am missing something obvious?! Besides the engine just imploding are there any things I should have checked? any thing I CAN check to verify what it may be? I was considering pulling the plugs again and checking compression too. Suggestions?! Thanks.

 

[flyweight]

Ignition problems?
Is the spark at the plug electrode Blue-ish?

The plug below is wet.

Common causes:

• Weak ignition component(s)
• Defective spark plug(s)
• Gasoline flooding cylinder
• Low compression
• Broken piston ring(s)
• Burnt Valve(s), Valve(s) not seating properly, Valve(s) clearance out of specs
• Contaminated fuel

Carburetor problems?
Have you checked to make sure the Chock Plate is fully opening?

 

[rwmeyer]

The plug on the right definitely looks oil fouled to the point of probably not firing. This would put fuel into the exhaust system and when the other plug fires...boom, a backfire! Locate your crankcase breather and verify that it's clean & working. The only other ways I can think of oil fouling is bad rings...requires leak-down test to verify... or valve guides... requires dismantle & measure. Bob

 

[workinonit]

If it runs and is just low on power it's likely a plug. I just had that happen to mine. I also had an ignition coil to go bad. Found that by pulling plug wires and isolating. Those plugs look kinda bad.

 

[schreib]

this morning it idled fine, no carb problems are evident;
did not view the spark at electrode, just black and wet. One appears not to even be firing-- even electrode is black, porcelain is black as night whereas other is whitish.

Plan to replace both plugs and one coil initially and go from there. . .
thanks!

 

[Ritz]

You may want to check the compression. A compression tester isn't that expensive if you've got a Harborfreight location nearby.

Compression Test Kit 8 Pc.

Compression Test Kit 8 Pc

harborfreight.com

Best,

 

[schreib]

You may want to check the compression. A compression tester isn't that expensive if you've got a Harborfreight location nearby.

Compression Test Kit 8 Pc.

Compression Test Kit 8 Pc

harborfreight.com

Best,

Yep, just checked it. After 4 or 5 cranks it runs up to 170+ psi-- manual indicates that is OK.

 

[Ritz]

Yep, just checked it. After 4 or 5 cranks it runs up to 170+ psi-- manual indicates that is OK.

Yeah, that's plenty for a V-twin like yours. Now just check for spark. If that's OK, then you've got something going on with fuel delivery. When was the last time you changed the fuel filter?

Best,

 

[denverguy]

Have you checked for spark?

 

[schreib]

I checked for spark and it is just great. Nice bright orange on my Lisle tester.
Confused why it could be a fuel issue. . . other side is running good. Fuel injection is into the throttle body, right? both cylinders are getting fuel from same throttle body? what am I missing?
on my way to buy plugs. . .

 

[schreib]

If it runs and is just low on power it's likely a plug. I just had that happen to mine. I also had an ignition coil to go bad. Found that by pulling plug wires and isolating. Those plugs look kinda bad.

Fixed it.

Spark Plug. The really wet plug was running a 0.042" gap-- + 0.012" too large-- 40%! Spec is 0.030"
The other plug was 0.008" LOW at .022"
I reset both to spec and it ran pretty well; let her warm up for a while, pulled the plugs and both looked closer to normal light brown on insulator on the better one and nearly so on the poor one. Put in two new plugs and all is good.

I bought this machine about 1.5 yrs ago and apparently never checked the plugs or did and found no problems. Who knows. I will monitor the plug "wetness" closlely now and see if there are also fuel delivery problems getting them too wet. . . ?! Still, it runs fine now.

Amazing how such a small thing can make an engine sound as if it is nearly dead. I had a good scare here.

 

[schreib]

Fixed it. Spark Plug. . . . I had a good scare here.

On the other hand. . . drove it a bit more and it is missing at random intervals. Runs and idles fine then nearly dies. . . again. NOT the plugs. Weird.

I am thinking it is electrical related??!#@@%@ any ideas folks?!

 

[rydplrs]

I’d put a fuel pressure gauge inline. A failing pump is usually completely dead, but occasionally they will fail by causing low pressure.

 

[schreib]

no gauge but it is old enough this is a no brainer to simply replace and try! thanks.

 

[rydplrs]

At almost $500 it’s not a part I’d buy for a pole and hope strategy

 

[x738]

I'm not normally an additive fan (beyond buying fuel from one of the brands that does have an additive package), but perhaps it's time to try one of the fuel system / combustion chamber cleaners.

example:

https://www.chevronlubricants.com/en_us/home/products/by_brand/techron.html?src-tab=products

(Not a specific recommendation as there are many available )

 

[schreib]

Yeah, I would agree, once I figure the main cause that an additive may be a good clean up item.

rydplrs: The fuel pump costs $80 on Amazon. . . Lots more than I figured, forgot this is fuel injected. . . just the same It makes sense to pull the pump and check it out, at least try pressure testing. . . I found this link on a search indicating it could be something simpler than the pump itself; heck it could be a plugged / bad injector even. . .
but I will have to relieve pressure before putzing with things . . . Time to read over manual etc and jump on it.

 

[x738]

I guess I was wondering if the 'missing at random intervals' it's having now after the plugs replaced is related to carbon that may have built up when it had poor spark.

 

[schreib]

I’d put a fuel pressure gauge inline. A failing pump is usually completely dead, but occasionally they will fail by causing low pressure.

Well, you sure sent me on the right path. I did some searching along the line of fuel supply and found one from back in 2013(lots of luck here!) that described my problem almost exactly and nearly the same solution worked for me. I pulled the pump from the tank(after removing entire rear of machine cover, 15 minutes) and after looking closely found a 1.5" long piece of rubber hose with half its lower hose clamp fallen off into the tank below. You could see(image here) the gas was backpressuring out into the tank instead of toward the engine. So, once again I am claiming victory. The tractor ran just fine and into the shed 150 yards away with no problem. I am hoping it will wake up next spring ready to run. . .
Thanks for all the help.

 

[schreib]

I guess I was wondering if the 'missing at random intervals' it's having now after the plugs replaced is related to carbon that may have built up when it had poor spark.

yup, and a good reason to clean 'er up. I agree despite having fixed the problem fuel pump feed hose leak. It can't hurt. thanks again.