New engine for Max IV

[alexu35]

Hi guys,
It is a time to replace the engine on my Max IV.
Presently I have Kohler command 25hp.
I couldn’t find the same specs. engine for a price which fits to my budget.
So, my current options:
1- Kohler Command 18hp with the same shaft dimensions as my old engine 1-1/8” X 4”. I believe it will be the easiest option to install just plug and play. My only concern is what if it will be too much underpowered?

2- Kohler Command 25hp. Shaft is 1-1/8 X 2.75”. So shaft is shorter by 1-1/4.
How critical is a shaft length? I don’t know.

3- Subaru EH -72 25hp engine with a good prise tag on it. I can get it for same money as 18hp Kohler. But shaft center of crank shaft is 2/3” lower than a Kohler. Which means I need to raise it or get smaller belt?
Any thoughts? Any input is appreciated.

[thebuggyman1]

What's your budjet? 27hp Kohler Engine ES Command Pro Commercial Air Cleaner Ariens 1-1/_ CH740-0091 | eBay

[alexu35]

In Canada that engine goes close to$3000.
So i'm trying to find something for $1600-1800

[MaxRules]

Whats wrong with the engine you have? I assume you are sure the Kohler you have is junk, or you wouldn't be replacing it with the same thing. The engine will usually out last the rest of the Max three times over if you don't run it out of oil.

[alexu35]

I bought it without checking the compression in the engiine . And afterwards when I checked it I found out it was only 30psig.I showed the engine to 3 mechanics and in general they recomended me to get a new one rather than spend money on repairs .

[msafi65]

I would at least tear down the 25 kohler and check cylinder walls if cylinders are in spec, rings and valve job shouldnt be more than 5-800$??? Thats a guestimate and the 25 Kohler is a great engine. Ive been looking at the subaru my self and they are impressive. Can get an engine driven fuel injection that runs off magneto even if battery is dead.(thats what the salesman told me ) If you go to the 18 kohler power will be ok. On one model,624cc the only difference in the 18hp and 20 is carburetor. If you go to the Sub I'dd put washers under to match original crank. Stock belt and clutch will work fine.

[BenDawg]

The Subarus are great engines. They rfe offering a 5 year unlimited hour warranty on them now. If the Subaru is the fuel injected one WOW would that be a great way to go.

[alexu35]

That subary which I found has engine mounted throttle and choke controls.
I'm wondering how difficult it would be to convert it to cable controls?

[msafi65]

I was talking to a factory rep at a trade show that had been selling them in Texas for oilfield support equipment. He was looking at a MAX and thought the throttle and choke would be easy to run remote. He also said if you have to shorten the crank stub that it would have to be cut with high speed cutoff wheel. cant cut it with a hacksaw.
I would air test your kohler with the rockerarms off and see if it may just have a bad valve. Might just do one head and run it to see what kind of oil consumption ect it has. Might get a couple years for a few $. good luck

[Noel Woods]

Here's one from small engine warehouse, add a radiator from a salvage yard, get a muffler, and you will be in business:



Made by Kohler

31HP Aegis Liquid Cooled, Horizontal 1-1/8"x4" Shaft, EFI, 25 Amp Alt, Electric Start, no Radiator

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Product Number: LH775S-0013
31HP Aegis Liquid Cooled EFI
Overhead Valve Design
Cast Iron Cylinder Sleeve
Mounting: Horizontal
Electric Start: Yes
Low Oil Shutdown
Fuel Tank: No Tank
Shaft Size: 1-1/8"Dx4"L
Muffler: Not Included
Manifold:
Made For: Tomcar
Shipping Weight: 151 Pounds

Condition: New
Warranty: 2-Year Manufacturer's Warranty
Returns: Limited Allowed
Dimensions L x W x H in
17 x 18.1 x 26.5


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List Price: $2,983.53
Our Low Price: $1,300.00

[alexu35]

Thanks to everyone for your help . I decided to go with kohler 18hp because it is the easiest to install for my model . I hope it will not be underpowered . Thank again everyone .