engine size issue question

[keakar]

i got an old Husqvarna 2246LS mower im trying to get in good working order and it has a kawasaki engine on it

it has a rough start issue where it surges with the choke but dies instantly if you turn off the choke and then after the engine runs for a short while and wants to die with the choke on, then the engine stays running after turning off the choke and it runs really good. i assume the pick up tube needs a bit of a cleanup so it gets better gas supply when starting but thats a separate issue from the question i have about this mower.

upon further investigation i see its a FH430V-CS04-R twin engine which, depending on where i look, its listed as a 14.5 hp - 15 hp engine, yet the mower originally came with a 22 hp B&S twin engine

i realize the hp ratings can vary a lot on small engines depending on how its measured but im pretty sure a 15 hp is not gonna work on a mower designed for a 22 hp engine or am i wrong?

i have a 20 hp B&S twin engine i can put in it but i want to find out if i NEED to replace that kawaasaki engine thats in it (i assume you cant go down more then 10% of the oem hp rating on engine swaps)

 

[gainestruk]

They over size engines on mowers to sell more, most people will buy what ever has most horsepower thinking it's the best mower, you could put an 18 hp single in it and it would work fine, my Gravley 1844XT commercial grade has a 18 hp Kohler Courage engine, it will mow faster than my back will stand.

 

[keakar]

They over size engines on mowers to sell more, most people will buy what ever has most horsepower thinking it's the best mower, you could put an 18 hp single in it and it would work fine, my Gravley 1844XT commercial grade has a 18 hp Kohler Courage engine, it will mow faster than my back will stand.

but isnt going from a 22 hp all the way down to a 15 hp a bit much? that is over a 25% reduction in engine hp to drive a 48" deck

 

[ILENGINE]

CC and JD back in the 70-80's would of had a 14-16 hp for that size deck. Horsepower sells mowers, Most don't need that much HP or they are overrating the HP

 

[Scrubcadet10]

but isnt going from a 22 hp all the way down to a 15 hp a bit much? that is over a 25% reduction in engine hp to drive a 48" deck

Keep in mind a we also have a Kubota g1800 with a 54" deck,3 blade,hydrostatic trans, with a 16HP engine...and it does just fine.

 

[gainestruk]

but isnt going from a 22 hp all the way down to a 15 hp a bit much? that is over a 25% reduction in engine hp to drive a 48" deck

I would try a 18 hp for it, if you want to go with twin just get as small hp as you can.

 

[Richie F]

It's not horsepower but the torque that does the work.

 

[keakar]

ok thanks guys, i had issues putting 14 hp and 15 hp engines in mowers that came with 19 hp engines and they almost all bogged down and struggled in tall grass

at that time the advice i got from online forum guys was "you can go up but you cant go down in hp more then 10% or the mower will struggle under heavy loads", i took that advice to heart since it mirrored what i was seeing in first hand observations so i believed it

i am not the type of by the book, buy new parts only, and repair rather then replace mechanic you guys are, i fix things at minimum cost and try to save mowers you guys may consider not worth it, but i just do it as a hobby and for beer money

i buy not so old mowers still in great shape to fix up and resell, so if i need an engine or tranny i would buy a second hand parts mower to get an engine or tranny that i need before spending $300 rebuilding the original one.

i can tell you guys know your stuff here so i greatly value learning things from you.

 

[keakar]

I would try a 18 hp for it, if you want to go with twin just get as small hp as you can.

well my only concern was the big drop in hp from 22 hp down to a 14.5 hp

if you think the 14.5 hp kawasaki has the power and the torque to run it then i will leave it be and just see what the carb issues are

i have a spare B&S 18.5 hp single and a B&S 20 hp twin engine not being used so either one is available and the kawasaki in it now is running great other then the cold start issues, once it has warmed up it has no issues

the kawasaki surges on start up with choke on and dies as soon as you turn the choke off so it doesnt seem to be getting fuel at idle until the engine starts warming up so im assuming its gunk in the carb needs to get hot to allow fuel to flow through the idle passages

this will be the first time i ever worked on a kawasaki lawnmower engine

 

[bertsmobile1]

When a mower is DESIGNED they work out the power required then up it by 10% .
From then on in every few seasons they toss in a bigger engine for the reasons stated above till you get idiot things like the local Greenfields running 24 Hp twin in a 34" mower that originally had an 8 Hp engine in it.
They eat drive belts because the engine is too powerful for the belt .
Professionals always want bigger engines so they can cut TALL WET WEEDY FIELDS faster and for them time is money so cutting at 4 mph makes a big difference to 2 mph
For most domestic users all a bigger engine does is consume more fuel .