[cparker88]

Hi All,

I've got a new to me 425 with ~890 hours. I do not believe it has had the cam gear replaced which is on my to-do this winter. In the mean time I'm trying to address a few issues that have cropped up but one of the biggest is a power loss. I have about an acre of relatively hilly yard. When mowing (especially uphill and through thicker grass) it really wants to die out. I'm frustrated because the old 48" 16.5 hp Craftsman I did was way better in the yard.

I've done a tune up, checked plugs - all the normal culprits.

Perhaps unrelated but also maybe related, I seem to have some level of an overheating issue. The front grille is melting where the LH side (if sitting mower) exhaust pipe is at it's most forward point.

Kind of at my wits end here so any input would be appreciated.

 

[arm]

I use a 425 to mow around the house, a half acre of that is Zoysia grass , low but thick. I slows the 425 down pretty much unless I go slow and that's with a 48" deck....I do the 4 acre field with the 455 it has a 54" deck....nothing slows it down. Nature of the beast I guess.

 

[cparker88]

I use a 425 to mow around the house, a half acre of that is Zoysia grass , low but thick. I slows the 425 down pretty much unless I go slow and that's with a 48" deck....I do the 4 acre field with the 455 it has a 54" deck....nothing slows it down. Nature of the beast I guess.

I just don't see how a 20hp can't out perform a 16.5 HP motor with a 48" deck. I feel like something has to be wrong given the thing barely wants to get up hills with the deck is engaged.

 

[CJadamec]

At this point I wouldn't put the cam gear off until winter. Or at the very least get into your engine a bit to make sure the valve timing is still correct.

That type of exhaust overheating is something that needs to be corrected quickly before you burn out the engine. You may have already skipped a tooth or two on the timing.

 

[cparker88]

At this point I wouldn't put the cam gear off until winter. Or at the very least get into your engine a bit to make sure the valve timing is still correct.

That type of exhaust overheating is something that needs to be corrected quickly before you burn out the engine. You may have already skipped a tooth or two on the timing.

Any thoughts on where to start with the overheating?

 

[rydplrs]

If timing is off you can’t believe anything else.

 

[Herminator]

@SullyBear

Aren’t the 425‘s the ones that lose power when going uphill when the fuel pump starts to fail?

 

[cparker88]

@sullybear. Aren’t the 425‘s the ones that lose power when going uphill when the fuel pump starts to fail?

So that’s what I’ve been reading but wasn’t sure whether or not the overheating was tied to it. The tech manual is fairly generic with trouble shooting.