4500Z Spark Plug Life

[prs]

Dave, you may be in trouble. Think'n too much like me, that is. I already have the colder set of plugs in stock in case the next inspection shows heat damage. I suspect the one gallon cooling system may be challenged and that Kubota has this puppy running a tad lean, thus hot, to appease some politician in California. This could have steam forming at the top of the head where the plugs need to transfer their heat. Steam is a lousy coolant. So, I flushed and dehydrated the cooling system before refilling with Evans coolant; no water, no steam. Next check should be pre-winter prep in November, will report.

prs

 

[3930dave]

I've heard of Evans, but never used it. Will be interesting to see how it performs in your application.

Your comment had me thinking about "water wetter" type products that operate by modifying the fluid/metal boundary conditions, to increase heat transfer. Done right, Evans could be doing the same thing.....

A lot of modern equipment does run lean. You seem to be on top of your maintenance...... I know in the old days, baling hay meant we had to constantly keep blowing off the radiator area - dry chaff always managed to accumulate at an incredible rate.

If your electrical system is up to it (??), perhaps an aux. cooling fan might help - even a smaller one might be the extra margin you need....

Rgds, D.

 

[wrenchit]

RC12YC Champions is all I use. If your Kabota is eating plugs then you have other issues then bad spark plugs.

 

[prs]

K7LN, I have over 100,000 miles on a Goldwing with Evans with no overhearing and overhearing was an issue with that 2002 model. My 1982 JD-650 would over-heat when worked hard and long, but going to the Evans, it htas not for the past 14 years. I run Goldwing with a non pressurized cap, the Ventrac with a cap with specified pressure, and the JD has an OE pressurized cap.

I agree that the Evans has a lower heat transfer rate at a given temp than water or 50:50. But, the Evans can operate at a much higher temp and as the temp rises, the heat transfer of the hotter Evans exceeds that of the cooler water based product and as the water based product begins to steam its heat transfer drops dramatically.

I worked the Ventrac hard and long today, will respond below to Wrenchit with observations.

Thanks for the response.

prs

 

[prs]

RC12YC Champions is all I use. If your Kabota is eating plugs then you have other issues then bad spark plugs.

First, based upon your response to Mountaineer, I checked my header bolts. All were tight. Then, even though I have only put about 10 hours on these old plugs since last inspection and gapping; I pulled them before starting work this morning. NO SIGN of further heat damage and gaps were spot on at .025". No wetness noticed on plugs or in the head wells. Set them back in and it worked hard and ran like a top all day.

I never expected "bad" (poor quality) plugs; although the heavy rust on the hex bolt portion did give me pause. My working diagnosis is the lean EPA carb tune and my tendency to run full tilt for long hours in hot weather was challenging the cooling system. The plug wires having those well seal plugs may have been making matters worse with condensation.

I have always had good service with Champion plugs too, but also no troubles in past with NGK or Denso.

Thanks for the response!

prs