Honda gx340 ?

#1
Has anyone ever tried putting on a honda gx340 11hp engine on a frame before? What kind of clutches did you use? I mocked the engine up and it fits inside the frame but the shaft sticks way far out past the frame I know this could be fixed with putting a jack shaft behind the motor with clutches but what kind of clutches would I need to handle the h.p.? Would a series 30 clutch work or would I have to use a series 40. The motor has a one inch shaft.
 
#2
I am exploring similar possibilities with my BAJA MB165 and while the motors will fit I cannot locate any kind of centrifugal
clutch that fits one inch crankshaft and has teeth for 420 chain. Well for that matter.... I cannot fine any centrifugal clutch
with one inch bore because I guess I could use any teeth size and I could change the sprocket on jackshaft to be compatible.
I would like to see some chart explaining the strength of different size chains as the most common on go karts seems to
be #35 and #41 I think. My Baha MB165 uses all #420 chain. That #420 seems rarely used on other mfgrs vehicles.

If clutch and jackshaft are not available for one inch crankshafts then I need to pursue belt driven torq converters I suppose.

Where is the best info on torq converters that will work with one inch crankshafts ?
 
#7
I am exploring similar possibilities with my BAJA MB165 and while the motors will fit I cannot locate any kind of centrifugal
clutch that fits one inch crankshaft and has teeth for 420 chain. Well for that matter.... I cannot fine any centrifugal clutch
with one inch bore because I guess I could use any teeth size and I could change the sprocket on jackshaft to be compatible.
I would like to see some chart explaining the strength of different size chains as the most common on go karts seems to
be #35 and #41 I think. My Baha MB165 uses all #420 chain. That #420 seems rarely used on other mfgrs vehicles.

If clutch and jackshaft are not available for one inch crankshafts then I need to pursue belt driven torq converters I suppose.

Where is the best info on torq converters that will work with one inch crankshafts ?
A 420 is a little stronger than a 41.
It fits on sprockets intended for 40 chain.

You can not mix and match 41 and 40 and you should not use a 420 on a 41 sprocket ( a narrower chain )

You can use a big block on a 165.
Big though, heavy and not much room for your feet.
The Briggs 305 is a smaller case size and offers more power and displacement.
Its a very good engine.
One fellow here put a vtwin in his 165
 
Last edited:
#8
iv got a gx390 on my lil indian. with jackshaft and 35 chain. to get the clutch in further i took the crank out of the engine and turned the shaft to 1 inch all the way up to the engine seal and recut the keyway to slide the clutch like an extra 2 inches closer to the engine.also milled the side cover down so theres no interference.
 
#9
A 420 is a little stronger than a 41.

You can use a big block on a 165.
Big though, heavy and not much room for your feet.
The Briggs 305 is a smaller case size and offers more power and displacement.
Its a very good engine.
I am not sure what is meant by big block other than as it applies to the Briggs V-Twins.
Your mention of the Briggs 305 did result in me finding out that in 2007 Briggs was calling
a special race prep version of the 305 Vanguard the "ANIMAL" and some were producing 35 hp
at 7500 rpms on methanol. I really would like to find out more about available off the shelf
parts for the 305 but the Karting authorities decided the 305 was much too powerful and downsized
the current Class "Animal" to 205 cc. Meaning they are not so popular anymore and bolt on stuff available
is likely to be old stuff. ( I dont care )
 

trinik7597

Active Member
#11
fastermotors.net for all things briggs ... but a gx 340 will make gobs of power too .... just going to cost some money big block parts are like double small block stuff
 
Top