Subaru EH41 Rebuild?

[garagedog]

I'm helping a neighbor out by rebuilding his Subaru/Robin 13.5hp EH41 for his water truck (water pump). I'll be at least replacing the piston and going through everything.
Any help or suggestions are appreciated.
1. What is the best website to order OEM parts from?
2. Is there any particular parts that wear out on this model (valves, crank bearings etc)?
3. If this motor is too far gone, what do you suggest (make/model) is a good replacement?
-Thank you very much for your advice and shared experience
Bob

 

[Rivets]

Answer to question #1 I’d recommend PartsTree if you don’t have a good repair shop in your area. Reason I recommend going to a repair shop first, is that they can double check your part numbers and if they make a mistake it is easy to return.
Answer to questions #2&#3, I doubt if anyone will be able to do so. We are not standing next to you with a strong drink in hand to see what you see. If you are replacing the piston, then do the rings also. Here’s the questions we have for you.
1. How experienced of a mechanic are you. This will dictate what we recommend doing?
2. How much money are you willing to spend? Subaru parts can get very expensive.
3. How deep into this rebuild are you going to go? Replacing piston and rings, deglazing or honing cylinder, cutting and relapsing valves, rebuilding carb. All these areas will dictate our answers.
4. Do you have the tools and equipment to do the job you want to do. Or a good repair shop to assist you?

If you post back, make sure you include all engine numbers and a few pictures of what you see inside. Here is a service manual which might be of some help. Remember that there are many good techs here to help, but we are hundreds if not thousands of miles from you so you must help us.

https://subarupower.com/wp-content/uploads/2014/07/subaru-eh-engines-eh36-eh41-service.pdf

 

[garagedog]

Answer to question #1 I’d recommend PartsTree if you don’t have a good repair shop in your area. Reason I recommend going to a repair shop first, is that they can double check your part numbers and if they make a mistake it is easy to return.
Answer to questions #2&#3, I doubt if anyone will be able to do so. We are not standing next to you with a strong drink in hand to see what you see. If you are replacing the piston, then do the rings also. Here’s the questions we have for you.
1. How experienced of a mechanic are you. This will dictate what we recommend doing?
2. How much money are you willing to spend? Subaru parts can get very expensive.
3. How deep into this rebuild are you going to go? Replacing piston and rings, deglazing or honing cylinder, cutting and relapsing valves, rebuilding carb. All these areas will dictate our answers.
4. Do you have the tools and equipment to do the job you want to do. Or a good repair shop to assist you?

If you post back, make sure you include all engine numbers and a few pictures of what you see inside. Here is a service manual which might be of some help. Remember that there are many good techs here to help, but we are hundreds if not thousands of miles from you so you must help us.

https://subarupower.com/wp-content/uploads/2014/07/subaru-eh-engines-eh36-eh41-service.pdf

Thank you for your help. EH410YS10026847
I do have a copy of that .pdf service manual, thank you.
1. How experienced of a mechanic are you. I'm very experienced (30+yrs) in single cylinder engines although I mainly service and do ground up restores on dirtbikes.
2. How much money are you willing to spend? I am assuming my neighbor will spend upwards of 600 - $900. More than that he may want to buy new.
3. How deep into this rebuild are you going to go? Replacing piston and rings, deglazing or honing cylinder, cutting and relapsing valves, rebuilding carb. All these areas will dictate our answers.
4. Do you have the tools and equipment to do the job you want to do. Or a good repair shop to assist you?
I plan on doing all those things listed #3, #4. Local machine shop will bore cylinder and cut seats if necessary.
I haven't taken it apart yet. I'm doing a little research before I dive in. Starting soon though.

 

[ILENGINE]

You can pick up some decent engines in that price range with a new 3 year warranty.

 

[garagedog]

You can pick up some decent engines in that price range with a new 3 year warranty.

Which price range? 600-900? Or the cost of new Subaru 13.5? (~$1700 ??)

 

[ILENGINE]

Which price range? 600-900? Or the cost of new Subaru 13.5? (~$1700 ??)

Either a Honda GX or a new Kohler in that $800-900 range. Especially since Subaru stopped production of engines, and their other industrial products in 2017.

 

[garagedog]

Either a Honda GX or a new Kohler in that $800-900 range. Especially since Subaru stopped production of engines, and their other industrial products in 2017.

Thank you for that info. That is very helpful.
I assume you are referring to the gx390 and the Kohler command pro 440 ??

Original Subaru has 13.5hp. The Honda and Kohler you mentioned will equal that output?
**Scratch this question.... I see there is a Max HP and continuous hp. Got it!

(sorry for such noobie questions)

 

[Rivets]

Here’s a quick breakdown of what it would cost if the engine rebuild would cost if it was brought to me. Remember all prices are approximate, as I would have to see all internal parts condition before getting a more accurate quote.
1. Parts $400-$450. Piston/rings—-Gasket set—-Carb or kit—-Air Filter—-Plug, oil etc.
2. Labor $400-$600. 5-8 hours at $80/hr. Would not include cylinder boring or valve and seat cutting. I don’t know what you charge for labor.

Looks like estimate of $750-$1200 before opening up the unit.

This is also based on availability of parts. I did check some part numbers, but not all. Internet says they are available, but I’ve never trust what I see. That’s why I recommend going through a repair shop To assist in getting parts. To me it looks like you must make a decision, as I never recommend rebuilding any engine where the rebuild costs more than 50% of new. Just my opinion.

 

[ILENGINE]

And also using Rivets estimates is the reason I don't attempt to overhaul an engine if it can be replaced for less than $2500.

 

[garagedog]

Thanks guys. Your input is helpful. Appreciate it!
I'll post an update after I speak with the owner.
I'm hoping he wants the Honda GX390