Hello All-Advice needed.

[Whitetrashrocker]

I think denny owns CometBelts.c0m or something.
Always promoting like a soccer mom. Lol

 

[gjones5252]

May be your idle adjustment is set a bit too high.
Set the back tires up on blocks so you can watch the cvt work. You should see the driven sheave let loose of the belt.

I thought that too. I put a stronger spring on the throttle control. That helped for sure.
Also the idle adjustment screw is as far as it could be out to make a difference.
It’s just that some times the belt catches and sometime it doesn’t. It’s weird.

 

[bob58o]

Make sure belt/pulley alignment is good.
If good, loosen engine mounting bolts.
Bump engine back an 1/8” or so in the slotted holes in the engine mounting plate.
Tighten engine mounting bolts.

After belt breaks in, bump engine fowarrd to take up slack in belt if needed.

 

[gjones5252]

Make sure belt/pulley alignment is good.
If good, loosen engine mounting bolts.
Bump engine back an 1/8” or so in the slotted holes in the engine mounting plate.
Tighten engine mounting bolts.

After belt breaks in, bump engine fowarrd to take up slack in belt if ok sweet. I may have a tiny bit left in the mounting holes. Thank you

 

[bob58o]

I think I’ve also used some smaller bolts to squeeze a tiny bit of adjustment out of the slots.

Using 5/16” bolts instead of 3/8” bolts might could getcha an xtra 1/32” of play.

 

[Whitetrashrocker]

I think I’ve also used some smaller bolts to squeeze a tiny bit of adjustment out of the slots.

Using 5/16” bolts instead of 3/8” bolts might could getcha an xtra 1/32” of play.

But you also get lateral play along with rotational play.
Now your pullies or sprockets are mis-aligned.

 

[bob58o]

But you also get lateral play along with rotational play.
Now your pullies or sprockets are mis-aligned.

It’s the clamping force that holds it in place. So if you keep things aligned when tightening, the clamping tween the bolt head and nut (stretching of threads) is what should holds it in place. The thicker bolt diameter is good for keeping things aligned when tightening (also for stronger threads). Unless I’m wrong and the shear strength is what it’s important here?

Grade 8 fine thread 5/16” isn’t too far off from 3/8 grade 5 coarse thread with clamp / tensile strength. I think…?

over 4 bolts? If 20,800 lbs of clamping force won’t hold it…

 

[Whitetrashrocker]

Hook, line, and sinker Bob. Lol.

I was hoping for the angular misalignment calculation with 1/32 over the 12 or so inches.

I'm guessing clamp strength is what's holding till the shear force overcomes the frictional resistance of the material.
Ever see when they interleave a couple books and try to pull them apart?

 

[gjones5252]

Thank you all for your help. We are at a stopping point while we work on some other projects. I think I either need to lube the driver pulley or get a longer belt. I have the engine and gear system as close together as possible. The driver pull seems to get stuck and sometimes will close all the way and other times it will not. Before it would just do a run away thing and keep going but with the team brake installed it will now stall the engine when you try to override it.
It runs well and is pretty torquey for the weight. We can carry two full grown adults and it does well. I wish it was faster but I am happy about the speed each time a kid drives it.
Next steps are batteries and a light or two.
Thank you again and this would not have been finished without the help of this forum.

 

[gjones5252]

After taking apart the driver it shows that my weight have popped over their appropriate spots. How do I avoid this in the future?

 

[Whitetrashrocker]

You have 3 weights and 3 springs right?
Here's a video.

 

[gjones5252]

You have 3 weights and 3 springs right?
Here's a video.

Yes three weight and three spring but it looks like at some point they popped out of the retainers. I am not sure what would have caused this.
I took it apart and lined and cleaned. So far working much better. But I am thinking about putting different spring/weights to keep it from engage so early.

 

[panchothedog]

The lighter weights and stronger springs ( 2 separate items ) about $40 for both will prevent that from happening, as well as raise the engagement rpm. The fact that the weights already did this, the springs must be totally worn out.

 

[gjones5252]

I have not yet got a chance to order the new springs, but it does the same thing about every hour of driving. I was hoping to get some insight from everyone regarding speed. I am maxing out around 18-19 mph. I am not sure that is a problem for me, but just trying to make sure that that all seems right.
With recent rains, when driving, it will kick out the tired and get moving, which most who drive it consider to be pretty quick however, it quickly tops out at its speed, which I assume is the governor. Given my tires, sprockets, and setup, does this seem correct? I thought people were telling me it should be a bit faster on the top end, and I am just worried I may have miscalculated something.

 

[bob58o]

20 mph might be right for 3600 rpm with a governor.

-What size TIRE diameter?

-What sprockets are you using? How many teeth on the gearbox? How many on the axle?

-What gearbox is it? I’ll have to look up the internal reduction ratio of the gearbox unless you know it.

 

[gjones5252]

tire size 20x10-9 and 19x7-8
10:60 for the gear ratio for the chain
Gear Ratio: Forward- 1:2; Reverse- 1:2:6

 

[bob58o]

Does that mean

1.2 :1 in F and 2.6 :1 in reverse?

 

[bob58o]

I would expect 3600 RPM to be closer to 28 mph with that set up.

if the gearbox was backwards, I’d expect 3600 rpm to be 14mph.

Is the tire pressure maxed out?

 

[gjones5252]

Regarding tire pressure, I would have to check for specifics, but they are not aired down or running low.

40-SERIES-GO-KART-FORWARD-REVERSE-GEAR-BOX

40 Series GO KART FORWARD REVERSE GEAR BOX, GO KART FORWARD NEUTRAL REVERSE GEAR BOX Replaces COMET PART.

blastled.com

this is the gear box.