I have JD 420 and it had P220 and I changed out with P224,

[etap]

I  bought a john deere 420 riding mower,and when I got it home,I checked compression in both cylinders and had 90#  in one other one had nothing. It had a broken rod in it,so the  guy give me his P224 onan which is 24hp out of his bob cat,a good running engine. I was wondering if I am messing up putting the bigger engine in, rather than rebuild the one that the tractor came with. Will that depreciate the tractor by not being original. THX

[celliott]

I dont have any idea what you just said  :D I can welcome you to the forum though, I'm sure a more knowledgable person than myself will come along to answer your question. It may also help to elaborate, go into a bit more detail with your question.

Much clearer now, thanks!

[Dave Shepard]

I'm going out on a limb here, but I'm guessing the 420 is a gator, and the P220 and P224 are Onan engines?

[beenthere]

etap
Welcome to the forum

Dave, not a Gator

A lawn tractor in the mid to late 80's and a good one at that. The 420 lawn tractor is a classic. Pre-runner of the 4x5 series (425,445, 455) from around '95 - '03.  The 420 has hyd. tranny with control on the dash. Later the 4x5's had hst forward/reverse pedals.

http://www.weekendfreedommachines.com/400/model400.html

I'd say if you are going to fix it up to use it, then the bigger engine would be just fine.

If you are going to fix it up to keep it as a collector item, but use it as well, then sticking with the bonifide 20 hp.

Seems for a runner, neither decision should depreciate the value. If the block in the P220 is good, I'd fix that up (either to install or to sell). IMO  

[Don_Papenburg]

Put in the running motor .  Find out how many hours it has .  The motor will last a long time ,but needs rebuilt around 1000 hrs .  An old JD dealer told me that after 1000 hrs. the chance of rods breaking or bearing spinning is real good . It is cheaper to repair before that happens. The extra four hp will make that a fast mower , I had to slow in the taller grass with mine . I could mow at 10 mph if I cut before it got real long .  The diesel 430 will power though them tough spots. Alittle more torque than the gas burner.   I still wish I had kept my 420. That series was the best built since the original 110s

[sandhills]

My dad has a 110, they just don't make'm like that anymore!