Problem with after market driven pulley on trail master

[Denny]

If he locked the governor out all you should have to do is be patient and keep racing him. Eventually the governor or the rod will let go and then you’ll beat him! The governor should be completely removed and a billet hd rod installed.

 

[bob58o]

I guess I’d need some more specific details to give good advice. My advice is just guessing thus far.

0.) is your governor still functioning?

1.) Gearbox Ratio
What is the internal reduction ratio of the gearbox? What make/model is the gearbox? I just looked up gokart gearbox and the googles told me 1:1.3. This might be 1.3 : 1 (underdriven) or maybe 1 : 1.3 (overdriven). Look up your model.


2.) Tire Diameter.
You can fill the tires, mark the spot on a rear tire where it contacts the pavement. Mark same spot on pavement. Push kart forward until marked spot on tire contacts pavement again. Measure distance traveled. This gives circumference of tire. Better than just trying to measure diameter.

3.) Count the teeth on the sprockets.
80 and 9 might be correct, but better to be sure.

4.) Top speed.
Download a gps speedometer app and see how fast you go. Top speed on flat ground.

5.) RPM
An hour meter / tachometer is cheap. Less than $15. Very helpful in tuning gear ratios.

0-4 are free and easy. Give us the details. #5 is not needed and does cost money but very helpful.

Also are you trying to win a race that is 1/16th mile, 1/8th mile, 1/4 mile, 100 laps around the block?

 

[bob58o]

Assuming 16” Tires
Assuming 5200 Max RPM
Assuming 1.3 :1 Gearbox Ratio (under driven output)
Assuming 6” driven unit with 0.9 : 1 ratio (over driven output)

16” tires = 4.19 feet per axel revolution
5 : 1 sprocket ratio

5.85 :1 overall ratio

42 mph at 5200 RPM

This ratio gives best shot at top speed with stock springs and stock rod (if gov has been removed or adjusted to allow such RPMs).

To get there you would need 5 : 1 sprocket ratio (assuming my assumptions were assumed correctly)

5:1 sprocket ratio examples….
80 : 16
45 : 9
50 : 10
55 : 11
60 : 12
65 : 13
70 : 14
75 : 15

 

[Ryanhodge2715]

Yesss man thanks for taking the time to do this. I'm on baby duty this evening but will Def to some test an let you know more details tomorrow. I knew an know nothing of gear ratios. This is great just what I need to be taking in. Not sure what a gear box is either it has a 6 in driven pulley. An a basic Amazon clutch for the TV. But it is a trail master mid xrx. The rest I will get tomorrow forsure.

 

[bob58o]

Ok, I guess you don’t have a gear box.
So forget that.
And instead of 5 :1 sprocket ratio, try for 6.5 :1 sprocket ratio.

80 :12
58 :9
65 :10
72 :11

Easiest is swapping the font sprocket to a 12T
Since 1/2” pitch chain sprocket with 80T is huge… I assume you are using #35 chain. This is the sprocket that comes with most TC kits.

5/8” Bore
12T
#35

I forget if the correct style sprocket is “B Style” or “C style”

Some sprockets have built in key.
Some have “spacers” on both sides of sprocket.

I’m pretty sure the “c style” in the Amazon link is what you want. The go power sports link has the built in key.

click ->

Amazon.com: Jackshaft Sprocket C Type, 35 Chain， 5/8 Bore, 3/16" Keyway, 12 Tooth for Torque Converters is Found On Many Go-Karts and Mini Bikes : Automotive

Buy Jackshaft Sprocket C Type, 35 Chain， 5/8 Bore, 3/16" Keyway, 12 Tooth for Torque Converters is Found On Many Go-Karts and Mini Bikes: Sprockets - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

a.co

12T #35 or 10T# 41 5/8B Sprocket

The 12t#35 or 10t#41 5/8B Sprocket is a high-quality sprocket designed for use in a variety of small vehicles, including go-karts, mini bikes, and other similar applications. This sprocket is made of top-grade materials to ensure durability and reliability, providing a smooth and efficient power...

www.gopowersports.com

Amazon.com: Jackshaft Sprocket C Type, 35 Chain， 5/8 Bore, 3/16" Keyway, 12 Tooth for Torque Converters is Found On Many Go-Karts and Mini Bikes : Automotive

Buy Jackshaft Sprocket C Type, 35 Chain， 5/8 Bore, 3/16" Keyway, 12 Tooth for Torque Converters is Found On Many Go-Karts and Mini Bikes: Sprockets - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

a.co

 

[Ryanhodge2715]

Sweet cheap too! I think it has a 420 chain on it. Just ran it with cheep speedometer app best I got was 30 flat...an it's a 60 tooth on the back. My neighbor got me yet again smh. He's running a 9 tooth as well but couldn't count what axel sprocket was looked like about 45 or 50. We going for top end like half mile road.

 

[Ryanhodge2715]

Till I get new sprockets do you think changing my driven pully will help increase top end? Or that just changes what rpm it opens at.

 

[Ryanhodge2715]

An I know I could look it up but would like yalls opinion. Are these octane boosters worth using? Reckon it gives you a little edge?

 

[Ryanhodge2715]

An I know I could look it up but would like yalls opinion. Are these octane boosters worth using? Reckon it gives you a little edge?

 

[Denny]

Snake oil. Save your money. Go to a 10 tooth with a 60 tooth axle sprocket. You could maybe even get by with a 56 tooth axle sprocket with the 10 tooth drive sprocket.

 

[bob58o]

What is status of your governor?

28-30 mph is what I’d expect you to achieve at 3600 - 3800 RPM with 60 : 9, 6” Driven, and 16” Tires.

At 5200 RPM, this would be 40 mph

Are we sure about the 16” tires?
Or is 16” like the 80T sprocket?

Also… think power to weight ratio.
For example …

6HP engine on 200 lbs kart.
0.03 HP per Pound

vs slightly modified engine on 400 lb kart.
8HP on 400 lb kart
0.02 HP per pound.

The modified engine added 25% more HP but if the kart weighs twice as much, the power to weight ratio ain’t gunna keep up

 

[Ryanhodge2715]

What is status of your governor?

28-30 mph is what I’d expect you to achieve at 3600 - 3800 RPM with 60 : 9, 6” Driven, and 16” Tires.

At 5200 RPM, this would be 40 mph

Are we sure about the 16” tires?
Or is 16” like the 80T sprocket?

Also… think power to weight ratio.
For example …

6HP engine on 200 lbs kart.
0.03 HP per Pound

vs slightly modified engine on 400 lb kart.
8HP on 400 lb kart
0.02 HP per pound.

The modified engine added 25% more HP but if the kart weighs twice as much, the power to weight ratio ain’t gunna keep up

Lol yessir I do apologize I'm just scratching the surface of this stuff. An I couldn't physically look an count them I took a guess. But I by passed the gov just locked out with a spring an bent a close hanger to work throttle. Not positive on cart weight but I can put it in the bed of my pick up alone so not much I wouldn't think. But I also have a 45 tooth sprocket from my other one!

 

[Ryanhodge2715]

That's also few week old clutch an brand new driven pulley. I know friction creates heat but damn that thing get sizzle your spit hot in 5 min of running.

 

[Ryanhodge2715]

Lol yessir I do apologize I'm just scratching the surface of this stuff. An I couldn't physically look an count them I took a guess. But I by passed the gov just locked out with a spring an bent a close hanger to work throttle. Not positive on cart weight but I can put it in the bed of my pick up alone so not much I wouldn't think. But I also have a 45 tooth sprocket from my other one!

Jesus I stand corrected it says 400 on Google but sure as hell don't think it is I'm no Macho man an I can Pick rear end up with one hand an slide a block under it with the other fairly easy

 

[Ryanhodge2715]

Now my stator I'm guessing is acting up as well smh!!! I don't know anything about the electrical side like that. But with the new fly wheel obviously didn't have the teeth too use a starter so I was planning to take it off so I unhooked battery an cables an two pads that went behind the stock fly wheel"new one couldnt fit with them behind it I assume those are only got charging the batter correct? Maybe it was just in the making any way an its not from me unhooking that? The spark plug only runs of the stator on top the fly wheel correct?

 

[BaconBitRacing]

I'm impressed by how far you've come with this project. I remember when it was a mess, but you are persistent and look where it got you!

 

[bob58o]

Personally I’d toss the hour meter / tachometer on there.

I’d like to know if 30 mph is at 5200 RPM and the TC is not fully shifted into high gear… Or The TC is shifted but you are only able to rev to 3600 RPM.

The coils mounted to the block (behind the flywheel) are just for charging a battery or lighting lights

magnet on outside of flywheel is for the spark.
Magnets inside the flywheel are for the charging / lighting coil.

As far as I know, billet / aftermarket flywheels do not have the magnets needed to make the charging system work.

 

[bob58o]

This is the spark plug ignition coil that works with the magnet on the outside of the flywheel.

 

[Ryanhodge2715]

Ok so I guess it just coincidentally kicked the bucket on me huh. An I will get a tachometer today or tomorrow an let you now. An thanks man that I am. Still plenty to learn but love learning new stuff An with this it gets my boy outside turning wrenches with me good bonding hobbie.

 

[Denny]

And the kid will remember the good times with the old man he had when he was a kid!