Engine swap; electric pto conversion.

[hlw49]

I remeber when you got a 42 inch cut with an 11 hp Briggs on it. Now you have to have a 18 or 20 hp engine. Over Kill

 

[StarTech]

I remeber when you got a 42 inch cut with an 11 hp Briggs on it. Now you have to have a 18 or 20 hp engine. Over Kill

Yes I remember one those 11hp OHV with 42" that came into my shop that would not even grass if it was slightly over grown. Since it was brand new I had my customer to return it for one that had a decent engine on it.

Now the old L head had a better engine that had lower hp ratings. The old 12.5hp L head would cut rings around the 16.5-19.5 OHV engines.

I personally have a 42" MTD that was a gutless wonder with a 16.5 hp OHV on it but now it has 21 hp OHV and walks through most grass I throw at it. I however had to upgrade the deck belt to a 5/8" one as the mower keep burning up the 1/2 belt.

 

[Slimbonic]

What's a L-head?

 

[Slimbonic]

Well that pretty kills it using a PTO clutch until the charging system is upgraded. A 3 amp just doesn't cut it.

Personally trying to use 21 hp with a 48"or larger deck is really pushing it anyway.

Upgrading the stator and installing a rectifier will fix the problem?

 

[StarTech]

What's a L-head?

A L-head is a side valve engine. They are engines with the valves mounted in the cylinder block instead of the cylinder head. Another old term is flat heads.

Upgrading the stator and installing a rectifier will fix the problem?

It will fix the electrical problem but it will not fix the lack of hp. 48" and 54" decks simply require more start up hp. So replacing an engine you should always go with the same hp or slightly larger. Most OEM will put the smallest engine that works with decks and some will even under power them. On top of that Kohler are rated closer to the true hp than Briggs. Even than most are rated at gross hp and not net hp.

Just my opinion but I would find at least another 25 hp engine. The 21 hp might start up the deck but it is going to struggle mowing heavy grass with the 48"+ deck.

 

[Slimbonic]

A L-head is a side valve engine. They are engines with the valves mounted in the cylinder block instead of the cylinder head. Another old term is flat heads.

It will fix the electrical problem but it will not fix the lack of hp. 48" and 54" decks simply require more start up hp. So replacing an engine you should always go with the same hp or slightly larger. Most OEM will put the smallest engine that works with decks and some will even under power them. On top of that Kohler are rated closer to the true hp than Briggs. Even than most are rated at gross hp and not net hp.

Just my opinion but I would find at least another 25 hp engine. The 21 hp might start up the deck but it is going to struggle mowing heavy grass with the 48"+ deck.

OK, thanks again for all your help. I really do appreciate it. Saving me money, too!
I may just try and rebuild the kohler. A broken push rod sent the ball end of it into the cylinder. It punished the head and valves after pinging around inside the cylinder before it completely stopped.
Not sure if there is any further damage (crank, rod, bearings, etc.).
Do y'all think it's worth rebuilding?
Hopefully it's just the head, piston and valves.
Or maybe just replacing the push rod, since the damage seems minimal to the piston and valves.
What are the chances of this motor surviving this catastrophe?
Again, it's a 25HP kohler pro.