Chain size and gear ratio help

[440dakota]

I'll be running a Gx390 on my trail horse and not sure on gear ratio? Motor is all stock (for now lol) Will a 35 chain work or do i have to get a 41? whats a good sproket size?

I guess i can't tell you what the clutch teeth size is since the motor won't be at my house till tomarrow afternoon. Any help will be appreciated, Thanks

 

[vette66_00]

I would use 40/41 for the 390. But if you wanted, a good quality #35 can support 20+ hp for a good amount of time. Alot of it has to do with chain quality and size. Cheap #35 chain is going to break with 10hp or more, I know from experience. :doah:

 

[440dakota]

Ok thanks for the info, Yeah the guy im getting the motor from later today said he's snaped the chain a few times on his go kart, he said the motor has balls but well see, once again thanks for the info

 

[Strigoi]

something like the RLV Extreme chain should hold up. i've been running it for awhile and haven't had any issues with it.

we can't really tell you anything about the gear ratio until we know how many teeth are on the clutch. what kind of riding are you looking to do?

 

[440dakota]

Ill post the teeth size later on today, I'll just be riding around the street for now. I just want a strong chain and good gear ratio so the chain won't fly off and cut my head off lol JK

 

[Strigoi]

we need the tire size too.

 

[440dakota]

The tire size is 4.10x3.50x6

I'll post up the teeth size after 5 (that when i go to pick it up)
Its a clone gx390, HF sells it for 399 i think? but im not paying that lol im getting a deal!

 

[440dakota]

Its a Noram clutch 12 tooth, so lmk what gear ratio to run, ill post a pic of the motor in a few, the header wont work for my mini and the carb is rigged so ill change that to a 32mm prob:smile:

 

[440dakota]

This is the gx390cc engine i just bought, It came with the noram clutch that has new pads and springs, it comes with a home made header that i can use (o well) the intak/carb is rigged but ill be buying the 32mm carb of akg. it also came with a Tiny-Tach all of this for only $150, and it ran smooth. I'll be looking to get some aftermarket parts soon, i'll also need a motor mount to set this on my frame, Also the gas tank is not staying, and ill buy a flywheel cover to dress it up... Any tips and info on what to do will be a great help

Ps the starter stuff will be removed and a pull cord added

Also the Gov is removed so ill be buying a arc rod before i run it

 

[Strigoi]

what kind of riding do you plan on doing? are you looking for something for hill climbing or just blasting around on pavement?

i'm not sure if that clutch will work either. it's designed for a belt and doesn't look like it can be mounted the other way. you're going to have to have a large frame or some sort of jackshaft setup to get that to line up.

that's still a good deal for $150.

 

[440dakota]

The clutch will work, Its got teeth on it? and yes im ganna have to take out the spacer on the shaft and flip the clutch so it should work.... I need to buy a motor mount because that motor is huge lol

Yeah ill just ride in the street/parking lot

 

[440dakota]

The bolt that goes in the shaft, Now does that come off counter clockwise?

 

[440dakota]

Here are pics of the Noram Clutch

 

[Strigoi]

are you sure that clutch can be mounted inboard or outboard? some can only go on one way.

 

[440dakota]

Im almost 100% sure it will work if i flip it. Guess i'll find out. Ya the motor is huge on the trail horse frame, The bike should haul after its done

 

[spyder_ryder]

cant wait to see what it looks like when its done

 

[The Restore Kid]

are you sure that clutch can be mounted inboard or outboard? some can only go on one way.

That's what I'm wondering too.. #1 the hole in the drum looks pretty small.. and #2 some clutches are only inborad or only outboard.. Usually outboard and most or more than not, are only one direction.. The shoes will not want to hook up correctly being spun the wrong direction. They will chatter and you can break stuff...

 

[440dakota]

The clutch will go on either way but i could make a motor mount to move the motor over and then line the clutch with the sproket? Its a heavy mini bike with this motor on there

 

[The Restore Kid]

Hm... yeah that would probably work.. If you look into your clutch more.. Do some research.. You MIGHT be able to run it both ways, OR at least be able to take the guts out and reverse them.. I have ran clutches backwards that are not supposed to be and not really had any MAJOR problems, but wouldn't SUGGEST doing it wrong against what they recommend. They are the ones who built it after all..

 

[kaptain krunch]

what kind of riding do you plan on doing? are you looking for something for hill climbing or just blasting around on pavement?

i'm not sure if that clutch will work either. it's designed for a belt and doesn't look like it can be mounted the other way. you're going to have to have a large frame or some sort of jackshaft setup to get that to line up.

that's still a good deal for $150.

I believe that clutch can be mounted inboard or outboard. and it is most definitely not a belt clutch.