# HSS1332ATD: GX390 or iGX390?



## cprstn54 (Feb 19, 2014)

Tried to download a GX390 user manual for my 389cc engine with S/N prefix GCBDT, only to learn there are none and that prefix is for the iGX390 engine.

1) Do I have an iGX390?

2) Are the basic engine parts (versus controls) the same for both engines?

3) Are there any practical differences?

Even curiouser, when I look up my engine S/N (GCBDT-1608615) on Honda's parts page, I am told the number is invalid. However, if I use GCBCT (a GX390 prefix) as the prefix, the number is valid. However, there is no doubt the letter stamped is a "D" and not a "C". 

Ken C
Frame No. SAFA-1001586


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## YSHSfan (Jun 25, 2014)

As far as I know the HSS1332 has a standard GX390 engine (maybe they use the same block as the iGX390).

This is a general purpose iGX390










Electronic governor and a few other features

Honda Engines | iGX390 4-Stroke Engine | Features, Specs, and Model Info


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## drmerdp (Feb 9, 2014)

As far as I know the iGX engines are in generators, and the hs1336 snowblower.

The main difference is the computer controlled throttle plate. No mechanical governor. 

Nothing *wrong with mechanical governors, but an electric governor will consistently outperform a mechanical one with... consistency.


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## arienskids (Jan 26, 2018)

I've seen the igx engines on some very high end commercial power washers


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## Freddy Ford (Jan 30, 2018)

The iGX is on my Honda generator, and the GX on the snowblower. The generator has an auto-throttle control feature which controls the output of the generator based on the load to conserve fuel.


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## RedOctobyr (Mar 2, 2014)

Assuming it's not an inverter generator, an auto-idle feature is fairly common, and can be implemented without the electronic throttle plate control. My Generac had that feature, using a mechanical governor, and a solenoid to toggle between idle and high governed RPMs. 

The real advantage, as drmerdp said, is that you can much more accurately control RPM under a load, to keep a 60 Hz output. My Generac had to be set to 61-63 Hz (3660-3780 RPM) with no load, to try and maintain roughly a 60 Hz (3600 RPM) output as a load was added. The mechanical governor would let the RPM sag some as the load increased. So if I started at 60 Hz, it would drop to maybe 57 Hz or so, when under a significant load. You had to pick your compromise. 

Whereas my little Honda EU2000i, with electronic throttle plate control, can hold its governed RPMs exactly, with anywhere from no electrical load, to the rated load. It has the ability to sense and make multiple adjustments, to get the engine speed right where it needs to be. Somewhat ironically, its RPM matters less than on my Generac, since its inverter is synthesizing the exact 60 Hz anyhow, from DC current. 

If yours *is* an inverter generator, then ignore my first point, since yours is presumably working just like mine


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