Command 25CV Cylinder Wall Damage

[Riddler]

What would cause this (photos attached)? The engine powers a 15 year old zero turn that gets worked pretty hard 3 months out of the year.

I'd like to understand the failure mechanism here so I can avoid (or delay) it with the new engine I'll have to put into this machine.

 

[Scrubcadet10]

I've never seen that, i would say lack of lubrication and overheating due to lack of airflow

 

[Riddler]

I've never seen that, i would say lack of lubrication and overheating due to lack of airflow

Yea, the fact that both cylinders experienced delamination of the nikasil cylinder wall coating suggests either or both overheating and lubrication failure.

I'm trying to decide between a short block or a complete engine. Heads looks good, but they are 15 years old, like everything else on the engine. Given the likelihood of prolonged overheating and/or lubrication failure(s), maybe complete engine is the way to go despite the steep price.

 

[7394]

both cylinders experienced delamination of the nikasil cylinder wall coating suggests either or both overheating and lubrication failure.

Wow !! I don't see what else could explain that..

 

[ILENGINE]

Yea, the fact that both cylinders experienced delamination of the nikasil cylinder wall coating suggests either or both overheating and lubrication failure.

I'm trying to decide between a short block or a complete engine. Heads looks good, but they are 15 years old, like everything else on the engine. Given the likelihood of prolonged overheating and/or lubrication failure(s), maybe complete engine is the way to go despite the steep price.

I am betting on overheating, but after 15 years who knows. Could of been just time and the coating started delaminating. Anyway. Here is something to consider Short block is a 90 day warranty whereas a new Kohler Command is a 3 year warranty.

 

[Riddler]

I am betting on overheating, but after 15 years who knows. Could of been just time and the coating started delaminating. Anyway. Here is something to consider Short block is a 90 day warranty whereas a new Kohler Command is a 3 year warranty.

The engine powers a MTD PRO Z 2560 zero turn mower. The complete engine for that machine is discontinued. For that reason, I'm thinking I have no choice but to find a short
block that works and go from there. I figure a
complete replacement engine designed for another machine won't interface correctly with this make and model. Is that a correct assumption?

 

[ILENGINE]

The main concern when replacing engine is crankshaft diameter and length. If staying within the same series of engine say going kohler command to kohler command then things are fairly simply. Changing brands or series can get interesting but in most cases can be doable. I was trying to see what was available in that size engine and looks like almost al the engines in the range are set up with the cyclonic HD air cleaner not like your more pancake style filter but if room permits isn't really a big deal either.

Looks like you have found a short block used on your current engine. My distributor doesn't show any in stock so may be hard to track one down

 

[Tiger Small Engine]

The main concern when replacing engine is crankshaft diameter and length. If staying within the same series of engine say going kohler command to kohler command then things are fairly simply. Changing brands or series can get interesting but in most cases can be doable. I was trying to see what was available in that size engine and looks like almost al the engines in the range are set up with the cyclonic HD air cleaner not like your more pancake style filter but if room permits isn't really a big deal either.

Looks like you have found a short block used on your current engine. My distributor doesn't show any in stock so may be hard to track one down

If you have time, source a good used suitable replacement.

 

[Riddler]

The main concern when replacing engine is crankshaft diameter and length. If staying within the same series of engine say going kohler command to kohler command then things are fairly simply. Changing brands or series can get interesting but in most cases can be doable. I was trying to see what was available in that size engine and looks like almost al the engines in the range are set up with the cyclonic HD air cleaner not like your more pancake style filter but if room permits isn't really a big deal either.

Looks like you have found a short block used on your current engine. My distributor doesn't show any in stock so may be hard to track one down

I'm willing to go with a complete engine if it won't present problems hooking up to the existing cables or wiring harness. When I research availabilty, complete CV-730 engines (which I understand replaced the CV-725 I have) seem tied to make and model of mower. The complete engine for my mower shows as "discontinued." What would be the trick to ordering a complete engine that I would have the least (if any) modifications to install?

 

[Riddler]

If you have time, source a good used suitable replacement.

I have checked on that currently. No luck. I wouldn't mind picking up the whole mower if it has low hours. Having a 2nd for parts would be nice. Saw I missed out on a really nice machine out-of-state that sold last April. I realize now that I should have been more proactive being on the look out for a 2nd unit.