You can use one of these top speed calculators:
http://www.oldminibikes.com/forum/engines-modifications/24064-top-speed-calculators.html
http://www.oldminibikes.com/forum/engines-modifications/24064-top-speed-calculators.html
Honda Horizontal OHV Engine 340cc, GX Series, 1in. x 3 31/64in. Shaft, Model# GX340UT1QA2 | 241cc - 390cc Honda Horizontal Engines | Northern Tool + Equipment
This is the engine. Any info on how to make 65mph would be awesome lol
This is the engine. Any info on how to make 65mph would be awesome lol
LOL I was talking about once you get it mounted.
For you to get that engine on a DB (doodlebug) to do 65mph. You will have to spend some money on upgrade parts for your Honda motor.
First off Rod, piston, flywheel (if you have the money and plan on rpm's over 5500 which maybe what it takes to get you to 65mph), cam, and upgraded valve train including rocker arms, spings, and valves.
Oh yah and ungovern it also which is free.
So after that at 5500 rpms with a 53 tooth rear gear and 15 front with stock tires you will do 65 mph.
For you to get that engine on a DB (doodlebug) to do 65mph. You will have to spend some money on upgrade parts for your Honda motor.
First off Rod, piston, flywheel (if you have the money and plan on rpm's over 5500 which maybe what it takes to get you to 65mph), cam, and upgraded valve train including rocker arms, spings, and valves.
Oh yah and ungovern it also which is free.
So after that at 5500 rpms with a 53 tooth rear gear and 15 front with stock tires you will do 65 mph.
The governor is not just that. It also goes into the motor and you have to remove the side case to remove the internal parts. Im pretty sure the gx 390 motors are the same setup as the 6.5 hp. Check out Affordable Go Karts - Home page - AGK - http://www.affordablegokarts.com for parts.
Also if Im wrong on the setup somebody please jump in a say so.
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Also if Im wrong on the setup somebody please jump in a say so.
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Once you identify the governor here's a thread with a checklist of to do's with suggestions for parts and tools. Good luck and welcome aboard...
http://www.oldminibikes.com/forum/honda-clone-engines/14199-governor.html
http://www.oldminibikes.com/forum/honda-clone-engines/14199-governor.html
It will still go about the same top speed as any other motor.. The horse power doesn't make speed, it only gives you the ability to make speed.. It will accelerate really fast but top speed is gonna be a typical speed being the engines all run the same speed.. You can go with a smaller sprocket on the wheel to go faster.. Here is a link to some top speed calculators that will tell you about how fast you will be moving when the engine is wound out.. http://www.oldminibikes.com/forum/engines-modifications/24064-top-speed-calculators.html
So according to that website if I use a 60t wheel sprocket with 10 inch tire and 32t clutch sprocket on stock 3600rpm engine I should hit 57mph correct me if I'm wrong. Plus I completely took out my governor tonight so that lands me at 5500rpm now? Sorry gujys this is all new to me and I wanna build this right and not waste too much money.
It's the (circumference) distance around the tire that decides how fast ya get going.. If it's a big ole doodlebug tire that is like a quad tire that is probably about right.. Sounds a little high for a 10 inch wheel (like a Rupp) but if it's a 10 inch rim with a hole bunch of rubber ( big old Doodlebug tire) that sounds about right... Especially with the 15 tooth driver...
WOW, you have a 32 tooch clutch!? thats gotta be huge. I have only seen 11-15 tooth clutches i think. Mounting a gx390 in a doodlebug takes a bit of work. Ontop of that, that engine is expensive to build. The pars cost about double what gx200 parts cost. Please get back to me about the 32 tooth clutch, im interested in seeing that.