Stage 3 212cc clone speed.

[Whitetrashrocker]

Go Kart Gear Ratio Speed Calculator

www.bmikarts.com

And get one of these.

 

[Whitetrashrocker]

Out of context but I love how a small question turned into an entire massive discussion

Bobs good at that.
He has great info. Listen to his wise words.

 

[bob58o]

US chain pitch is measured 1/8” increments.
Chains that start with 2 are 2/8” pitch.
Chains that start with 3 are 3/8” pitch.
Chains that start with 4 are 4/8” pitch.
Chain that start with 5 are 5/8” pitch.

most common karting chains are 3/8” or 4/8” (1/2”) so most chains start with 3 or 4 like #35 (3/8” pitch) or #40, #41, #420 (1/2” pitch).

I ask because common clutches are 12T for 3/8” pitch or 10T for 1/2”. But this is for 3/4” crankshafts. Did we confirm the crankshaft size?

3:1 is no good either.
assuming the clutch engages at 1800 RPM, the kart needs to be traveling 18 mph before the clutch stops slipping. And because the gear ratio is bad, it may take forever to get up to the 18 mph. Not good for stop and go, yard kart type driving.

 

[kart_goes_brrr]

US chain pitch is measured 1/8” increments.
Chains that start with 2 are 2/8” pitch.
Chains that start with 3 are 3/8” pitch.
Chains that start with 4 are 4/8” pitch.
Chain that start with 5 are 5/8” pitch.

most common karting chains are 3/8” or 4/8” (1/2”) so most chains start with 3 or 4 like #35 (3/8” pitch) or #40, #41, #420 (1/2” pitch).

I ask because common clutches are 12T for 3/8” pitch or 10T for 1/2”. But this is for 3/4” crankshafts. Did we confirm the crankshaft size?

3:1 is no good either.
assuming the clutch engages at 1800 RPM, the kart needs to be traveling 18 mph before the clutch stops slipping. And because the gear ratio is bad, it may take forever to get up to the 18 mph. Not good for stop and go, yard kart type driving.

So basically after I brake it would take forever to accelerate?

 

[kart_goes_brrr]

I just realized the chain I have doesn't even fit on the sprocket , the clutch that I have rn came with the chain, it's 19mm so it doesn't fit into the shaft. P.S the tires were 11". Man I'm lost.

 

[Denny]

Yea, it looks like your way too small sprocket is for #35 chain and your clutch and chain is #40.

 

[Sparkwizard]

And the clutch still does not fit the engine.

 

[Edwin Spangler]

Just throwing this out for reference... My kid has a ghost 212 on his b200r and he hits 60-65mph all day. 5.2-1 gearing

 

[kart_goes_brrr]

And the clutch still does not fit the engine.

No no that's the old one sorry , new one is coming In April

 

[kart_goes_brrr]

So, is there any solution with the 32 teeth sprocket? Or do I need another one?

 

[Sparkwizard]

You will need to change either the clutch or the sprocket. They both need to fit the same size chain.
I would gat a larger rear sprocket, or add a jackshaft.

 

[bob58o]

The only way I see a 32T sprocket working is if a jackshaft can be added….
Then going 12 on clutch to 22on jackshaft, then 12 on other jackshaft sprocket to 32 on rear…

 

[ezcome-ezgo]

With those tires, the clearance will require a jackshaft.

 

[kart_goes_brrr]

Wait, how does a jack shaft work?? I can't seem to find a video on YouTube, it's this one right?

 

[kart_goes_brrr]

Plus there's some pretty expensive options...

 

[kart_goes_brrr]

My problem here is, I can't change the sprocket for now because I can't find one that is compatible with my live axle, maybe I will ask the seller of the live axle if he has any larger sprocket, I'll update you guys.

 

[bob58o]

If you must keep the rear sprocket, identity what type of chain it needs. Then confirm the size of the crankshaft. You’d need a clutch and jackshaft sprockets that match the pitch of the rear sprocket. If it’s a 3/4” crankshaft, and a 1/2” pitch rear sprocket, you might be able to use a 30 series TAV / Torque converter with an 8T sprocket. I’d personally try to get a 30 series TAV with 7” Driven Unit. Your final gear ratio would be 4.4 : 1. With a 6” driven unit, the final ratio would be 3.6 : 1 and might smoke belts. If the rear sprocket is 3/8” pitch, then the TAV would use a 12T sprocket and again, it would be less than ideal.

1. Tell us the pitch of rear sprocket. (#35 3/8”, #420 1/2”, …)

2. Confirm the size of the crankshaft. ( 19mm, 3/4”, 20mm, …)

3. Tell us the size of the axle. Your sprocket/hub looks split, so swapping it out wouldn’t require much work.

below are the TAV and jackshafts examples. They both involve splitting the gear reduction into two steps. They both bolt up to the engine for easy installation. Alignment might be an issue depending on your kart and rear sprocket location along the axle .

 

[JimD]

Bob580 is giving you great info. Is it flat or hilly where you are? Hopefully flat and you have a friend that will push start you so you are easier on the clutch. The china clutch you have CANNOT take heat. Once you get the clutch HOT over 121C the spring has gone by-by. It will start engaging sooner and sooner until it is locked up when you go to pull start the engine. The clutch you have is a 10 tooth #41 chain and you need a #35 chain or a #219 chain, which ever you find then let us know. To get the speed you need your friend is going to push start the kart as you hit the gas just to prolong the life of the clutch because no matter what it is going to get HOT and you can use it to cook your dinner.

So the goal is to get your rpm up to at least 5,000 and if you can get a tire that is 12" in diameter and a clutch with 15 teeth and a rear sprocket of 44 teeth you can hit your goal. But it is not how fast you can go, it is how fast can you stop and not on a stationary object. Make sure you are also building into your speed factor some decent brakes. I am old but I got that way by listing to good advice.

 

[kart_goes_brrr]

If you must keep the rear sprocket, identity what type of chain it needs. Then confirm the size of the crankshaft. You’d need a clutch and jackshaft sprockets that match the pitch of the rear sprocket. If it’s a 3/4” crankshaft, and a 1/2” pitch rear sprocket, you might be able to use a 30 series TAV / Torque converter with an 8T sprocket. I’d personally try to get a 30 series TAV with 7” Driven Unit. Your final gear ratio would be 4.4 : 1. With a 6” driven unit, the final ratio would be 3.6 : 1 and might smoke belts. If the rear sprocket is 3/8” pitch, then the TAV would use a 12T sprocket and again, it would be less than ideal.

1. Tell us the pitch of rear sprocket. (#35 3/8”, #420 1/2”, …)

2. Confirm the size of the crankshaft. ( 19mm, 3/4”, 20mm, …)

3. Tell us the size of the axle. Yours looks split, so swapping it out wouldn’t require much work.

Alright so:
1. From what I understood it's probably #35, I'll still verify tomorrow, just to be sure, how do I verify?
2. 20mm confirmed.
3. Diameter or like length? I think it's 1" bore I'm still not sure, as for the length it's probably over 70cm. I still need to verify every thing I'm still not 100% sure.

Another thing is, I'm tight on the budget as
mentioned before and now I'm having some problems with delivery since it's getting late for anything to arrive on time. My only option here is the item needs to arrive before 10 April and needs to be shipped to Saudi Arabia (a relative is travelling there soon). I can't order directly from my country because they can't ship since there's some type of system where you have to pay triple the price of the item to get it inside the country, if they even allow you

 

[kart_goes_brrr]

Bob580 is giving you great info. Is it flat or hilly where you are? Hopefully flat and you have a friend that will push start you so you are easier on the clutch. The china clutch you have CANNOT take heat. Once you get the clutch HOT over 121C the spring has gone by-by. It will start engaging sooner and sooner until it is locked up when you go to pull start the engine. The clutch you have is a 10 tooth #41 chain and you need a #35 chain or a #219 chain, which ever you find then let us know. To get the speed you need your friend is going to push start the kart as you hit the gas just to prolong the life of the clutch because no matter what it is going to get HOT and you can use it to cook your dinner.

So the goal is to get your rpm up to at least 5,000 and if you can get a tire that is 12" in diameter and a clutch with 15 teeth and a rear sprocket of 44 teeth you can hit your goal. But it is not how fast you can go, it is how fast can you stop and not on a stationary object. Make sure you are also building into your speed factor some decent brakes. I am old but I got that way by listing to good advice.

It's flat, just streets. Also I didn't even know clutches can even get THAT hot . So actually some of the options I have are: 45 teeth sprocket (not sure if in stock), 16 teeth clutch, and 11" tires. Close enough or still a big difference? Don't worry about the brakes I got some really great ones. Could get you stationary in an instant . Anyways that's some of the things I got.