Belt screech

[Darian1m]

I have a 40 series torque converter on an 812 Manco. I did some searching for "squeal" "screech" and couldn't find anything on this topic.

At low RPMs the belt screeches some. I am assuming its slippage. Its a comet belt on a comet 40 series driver and driven. The spacing is set perfect for the belt. I refurbished the 40series per KartFabs video.

Any thoughts on what could be causing this?

 

[mckutzy]

What is the measured rear tire size and the gear ratio of the sprockets???

 

[Brianator]

Is it a new or old belt? If it's not new replace it and see if that cures it, they can become glazed and scream like a wildabeast! Lol

 

[mckutzy]

Well.... Id have to say the belt shrill is more akin to that of a banshee or a Drekavac.....You know, a more distinct note than that of a natural beast...

 

[Darian1m]

Well.... Id have to say the belt shrill is more akin to that of a banshee or a Drekavac.....You know, a more distinct note than that of a natural beast...

Love it.


Yes its a new belt. Rear tires are 22" sprocket on axle 54 teeth, sprocket on driven 9 teeth. 12 HP engine so lots of torque. I can hit about 27mph governed and this thing accelerates quickly.

The gear ratios and wheels are stock Manco FunKart 812 Series kart and they sold lots of these, I would be surprised if its a gearing issue.

 

[mckutzy]

22" OD??? measured from the ground?
You probably going to need to go up a size at least to a 72t, thats alot of torque on the system for that tire size...

 

[Brianator]

Well.... Id have to say the belt shrill is more akin to that of a banshee or a Drekavac.....You know, a more distinct note than that of a natural beast...

As long as it isn't the... Wendigo.... (gulp)

 

[landuse]

Love it.


Yes its a new belt. Rear tires are 22" sprocket on axle 54 teeth, sprocket on driven 9 teeth. 12 HP engine so lots of torque. I can hit about 27mph governed and this thing accelerates quickly.

The gear ratios and wheels are stock Manco FunKart 812 Series kart and they sold lots of these, I would be surprised if its a gearing issue.

So does it feel like you are taking off in third gear (sluggish with no power), or in first gear (tyres screeching like the belt you have)?

Like Mkutzy says, a 6:1 with 22" rears is a bit tall, but with a 12HP engine it might be ok.

 

[Darian1m]

So does it feel like you are taking off in third gear (sluggish with no power), or in first gear (tyres screeching like the belt you have)?

It does not feel like taking off in third gear it takes off quickly. But before it does there is some belt noise not very loud but I can hear the rubbing and a slight screech. Its takes a few seconds to engage the belt.

Maybe the belt is not perfectly aligned, I don't see how it's possible to do that when the driver and driven are both pointing outward. The comet 40 specs show the driven inward.

 

[mckutzy]

Let's see some pics of your setup...

 

[Darian1m]

ok will do. Pulled the engine off yesterday to remove the governor when I have it all put back together I will share some pics.

So here are some pics.

When I put the driver and driven back together I tried to make sure the belt was aligned as straight as I could make it. It was slightly off before which may have contributed to the slippage in the beginning. I also uploaded a couple of videos to youtube.

https://youtu.be/7q1OZ-p7F9M


https://youtu.be/Of4DLKApTR8

As you can see from the video the belt does not remain straight throughout the rpm range. I don't know if this is ok or not. The 40 series instructions have the driven unit spring side facing inward and requires a red spring for that set up. I have the yellow spring for the outward setup. Is the belt supposed to bend like that? I would think it would mess up the belt wear.

 

[Darian1m]

Well after I took the governor off and adjusted the pulleys to have the blet aligned during the point when the driver engages the belt the screech stopped. But now I am a little worried about the belt not being straight throughout the full range of RPMs.

These symmetrical comets seem to be designed for the driven facing inward to keep the belt aligned throughout the full range of engagement. Not sure if I have space to turn it inward. It will push my driver unit too far away from the engine. I guess I can buy a thicker mounting plate redrill some holes and shift the engine some to see if I can get them aligned.

Does anyone know where you can buy a thick steel plate?

 

[Darian1m]

So apparently the weights on the driver unit were not aligned with the top track. Thats why I was having all kinds of issues. Opened it up aligned everything put it back and the kart works fine now.

 

[Karts of Kaos]

nice!