# Repowering HS1132TA with GX390



## E350 (Apr 21, 2015)

I have a lightly used *Model No.: HS1132TA Serial No.: SZBF-1031604 *with the 11HP engine.

I also have a lightly used GX390 engine on a Kimpex snow blower which I am not going to use and will likely sell at a huge discount from what I paid for it.

I would like to put the GX390 engine on the HS1132TA. 

Do I need to post engine serial numbers for you guys to answer this question? If so, where do I find the engine serial numbers on the engines?

Is it doable? Is it a direct swap? 

Do I need some adapters, etc.? And if so what? I would like to buy the adapters ahead of doing the swap to minimize downtime.

This is what one of the members speculated in response to a pm:

_"[email protected] will be able to help you determine the age of the snowblower using the serial number._

_The footprint on GX340 and GX390 is the same (as far as I know).

If I was you I would swap the engines on the snowblower and the Kimplex, so you'll end up with a "HS1332" instead of the current HS1132 (GX390 engine has roughly 20% more power which you will appreciate on heavy wet snowfalls or EOD).

You'll also likely need to swap the flywheel and charge coil from the GX340 to the GX390.

What you may or may not encounter is that the crankshafts may be different GX340 should be 24mm, but the GX390 may have a 1" shaft (if it is the case you may have to get the pulleys bored out to fit in the GX390). If you are lucky the GX390 shaft will also be a 24mm and it will be a straight swap.

You may also have to swap the "winter dress" from the GX340 to the GX390 if it is not suited for winter use."_


----------



## 43128 (Feb 14, 2014)

usually the serial number on the gx240s and up are on the side of the engine opposite from the cylinder. on the gx200 and smaller you have to remove the gas tank to see the serial number


----------



## ELaw (Feb 4, 2015)

I'm not a Honda expert but I'd expect many things to be the same between the two engines, like mounting bolt pattern and the location of the crankshaft relative to same.

The most likely difference is the configuration (diameter and length) of the crankshaft, and your best bet might be to just pull the belt covers off both machines and eyeball/measure them.

Just measure carefully as if they use metric sizes as the person indicated in the PM, 24mm is very close to 1" but is not exactly the same (it's about 0.055" smaller). Of course if the pulley dimensions and positions were the same, the shaft specs would not matter - you could just leave the pulleys on their respective engines.


----------



## JnC (Feb 21, 2014)

Oddly enough I am contemplating something similar right now and am awaiting a response from Robert. 

I have a fully built HS1132 and a fully restored HS1132 waiting to be assembled at some point down the road. 

My idea was the same i.e. swapping the GX340 for a GX390 as the GX390 motor can be bought for around $200~$300 locally, used of course. The GX390 is a common motor on many log splitters and power washers. 

Most of the GX390s that I have found have the 1" shaft so the shaft has to be replaced. Best price for a new shaft is $81 from partspack. 

Pretty much everything else will be swapped over from the old GX340. The snowblower GX340 has different air guide, air guide/control cover, recoil starter and it doesnt have the low oil shut off so wiring might be a tad different which is no big issue. 

My only question to robert at this point is/was if the crankshaft from snowblower gx340 would work for the gx390. Secondly, if we were to get new crankshaft made for the snowblower gx390 would we have to get new pulleys or could the old pulleys and pulley key be used with the gx390 with upgraded crankshaft. 

At the moment I am waiting on hearing from robert as well before picking up the motor.


----------



## 43128 (Feb 14, 2014)

you should just be able to get new pulleys from tractor supply


----------



## JnC (Feb 21, 2014)

43128 said:


> you should just be able to get new pulleys from tractor supply



Thank you, sir. 

I know usually the shaft is 4" by 1" on the GX390 motors made for powerwashers. The shaft would have to be reduced in size at least 1". 

here are the sizes available through TSC. 

3" 

Phoenix Steel Drive Pulley, 1 in. Bore, 3 in. OD - For Life Out Here

3.5" 

Phoenix Steel Drive Pulley, 1 in. Bore, 3-1/2 in. OD - For Life Out Here

4"

Phoenix Steel Drive Pulley, 1 in. Bore, 4 in. OD - For Life Out Here

4.5"

Phoenix Steel Drive Pulley, 1 in. Bore, 4-1/2 in. OD - For Life Out Here

just need someone with an HS1332 or Robert to indicate what size the OEM auger and drive pulleys are, I am pretty sure they are 3", just need confirmation.


----------



## E350 (Apr 21, 2015)

*JnC*: If you haven't already started your repower thread, please make this thread your own, that way we can both post our common but separate endeavors here which will hopefully help others who follow.

If the shaft is indeed longer on the GX390, then can't I just cut it on my chop saw by the appropriate amount ~1" or will I be cutting off a keyway or other pulley attachment by doing so?

And then use a pulley from tractor supply? 

Or can I swap out the shaft from the 11HP Honda and put it into the GX390 and put the GX390 shaft into the 11HP?

*[email protected]*: I PM'd you with this link. Any help would be greatly appreciated.


----------



## JnC (Feb 21, 2014)

E350 said:


> *JnC*: If you haven't already started your repower thread, please make this thread your own, that way we can both post our common but separate endeavors here which will hopefully help others who follow.
> 
> If the shaft is indeed longer on the GX390, then can't I just cut it on my chop saw by the appropriate amount ~1" or will I be cutting off a keyway or other pulley attachment by doing so?
> 
> ...


After seeing that a TSC is pretty close by I am actually going to go that route as well. 

The shaft can be removed very easily, just needs the flywheel etc to be off of the motor, pretty much the whole motor needs to be stripped in order to take the shaft out. 

You can cut the shaft either right on the motor or take it out and cut it. Cutting the shaft would still leave you plenty of keyway as the keyway runs the length of the shaft i.e. all the 4".

Just make sure that you dont let too much heat to be created whilst cutting as that might damage the oil seal around the shaft. 

The mounting holes for the belt retainers that go around the pulleys can be found on pretty much all GX390s so I think we are good there, this is only an issue if you have a GX390 from a water pump or any other application that uses reduction gear boxes as in that case they often have crank case cover with different mounting holes to accommodate the gear box.


----------



## [email protected] (Nov 21, 2011)

JnC said:


> just need someone with an HS1332 or Robert to indicate what size the OEM auger and drive pulleys are, I am pretty sure they are 3", just need confirmation.


You've go mail.


----------



## JnC (Feb 21, 2014)

Picked up the powerwasher yesterday, so the upgrade has finally begin. I dont need to put the machine together right away as it wont be used this year hence have plenty of time to do the upgrade and research. 

My machine came with the 1" straight camshaft. 

A few more observsations from research

1) Flywheels are different depending on the coils being used. Since the power washer doesnt need to provide output for lights etc it doesnt have any factory lamp coil/s. There are no magnetos built on the inside of the flywheel either to generate power in conjunction with the coils. Neither are there teeth on the outside of the flywheel for the 120v electric starter. 

Hence the flywheel and coil/s would need to be swapped over IF you want to keep the lamp and want to keep the 120v starter. 

In my case I can do without the started but I need the auxiliary power supply. If all goes to plan the GX390 would have the GX340 flywheel (hopefully it fits) and 50W HS928 coils.


----------

