First Time Builder Belt Question

[hhuxxleyy]

Hi yall. Just got my hands on my first go kart through a marketplace trade, plan is to build it into a little kart dirt buggy with the guys. Only problem is it doesn’t drive. Clearly the belt is loose, but I feel like I’m missing some stuff. Not sure what motor it has, all I know is that it’s a Briggs 4 stroke 206cc. It doesn’t drive right now, because there’s barely any tension on the belt, the only way to get it tighter is to literally slide the motor back. any tips?

 

[panchothedog]

Yes, slide the engine. BTW, you DRIVE the kart. It either RUNS or it doesn't.

 

[Hellion]

Neat kart. Show us more.

The exact Briggs (and Stratton, poor guy barely gets any recognition these days lol) engine can de deciphered from a code written on the valve cover I think. It looks like a Briggs Intek 5.5 to 6 Horsepower. Good engine and one of the few OHV engines that were still made in USA.

And to reiterate, it's not crazy to slide the engine to tighten the belt. That's how it is done with chain drives too, to keep the chain tight after it stretches and wears.

 

[hhuxxleyy]

Yes, slide the engine. BTW, you DRIVE the kart. It either RUNS or it doesn't.

Sorry about that, I’m coming from the project car world where there’s a big difference between a car running and driving haha. We tried sliding the engine, ran into two issues. Still not enough tension on the belt with the engine all the way back, but as soon as we even tried rolling it the belt became crooked and started to make its way off the pulley.

 

[hhuxxleyy]

Neat kart. Show us more.

The exact Briggs (and Stratton, poor guy barely gets any recognition these days lol) engine can de deciphered from a code written on the valve cover I think. It looks like a Briggs Intek 5.5 to 6 Horsepower. Good engine and one of the few OHV engines that were still made in USA.

And to reiterate, it's not crazy to slide the engine to tighten the belt. That's how it is done with chain drives too, to keep the chain tight after it stretches and wears.

Here’s a few more pictures of the engine. It is labeled with Intek and OHV although there’s no serial number I can find clearly. We tried sliding the engine back and bumped into two issues, still not enough tension on the belt and it slid immediately, and as soon as we started rolling it the belt got crooked and started making its way off the pulley.

 

[panchothedog]

I don't think it's an optical illusion. I your first picture, the large gear and the small one on the engine do not look like they are aligned. Your engine looks cocked on an angle. This will cause the problem you are having.

 

[Sparkwizard]

Isn't that a cogged belt? I think it has teeth on the inside, and it should not "slip". If it slips, the teeth are gone.
Please replace the belt.

Check the alignment of the belt to the rear wheel. If your rear wheel smacked something, it could have bent the frame enough to cause the belt to be loose, and misaligned. I think your stub axle got bent rearward.

 

[hhuxxleyy]

Copy that. Thank you all for your replies, I’m gonna try some of that stuff today and see if I can get it working. I’m sure I’ll be back haha.

 

[Hellion]

If there is no more adjustment available for the belt via the engine, it may be possible to put a tensioner pulley on the belt, but that would require some fabrication and parts (a skateboard wheel would work well).

The engine looks like a poor fit especially around the air cleaner assembly -- the filter appears to be taped on. Hope it works well enough.

 

[hhuxxleyy]

If there is no more adjustment available for the belt via the engine, it may be possible to put a tensioner pulley on the belt, but that would require some fabrication and parts (a skateboard wheel would work well).

The engine looks like a poor fit especially around the air cleaner assembly -- the filter appears to be taped on. Hope it works well enough.

Yes, whoever the previous owner/builder was was definitely mechanically challenged. The engine was attached to the frame via 2 different kinds of bolts, some of which were upside down. We spent the first night of owning it cutting the bolts off to get the engine off and putting new hardware in. However, it was basically free (traded for a crappy 3D printer I never used) and the engine runs so I definitely can’t complain. When you say adjustment via the engine, do you mean left to right? The only obvious method of adjustment is sliding forwards and backward on the rails.

 

[Hellion]

No I meant forward and back, to adjust the drive belt.

 

[hhuxxleyy]

No I meant forward and back, to adjust the drive belt.

Gotcha. We’re gonna try that again today, and also try getting a new belt, but we’re still bumping into the issue of it going crooked. Is precision adjustment so the belt stays straight standard or is it common to install a guide on the cog to keep the belt in line?

 

[panchothedog]

When adjusting the engine fore and aft, there is always enough slop in the bolts that the engine can be turned 2 or 3 degrees to the right or left. This is more than enough to give you trouble with the belt. Pay attention and stand back away from the kart where you can put a good eyeball on it and make sure the wheel and drive sprocket or pully's are absolutely parallel.

 

[Edwin Spangler]

Dont trust your own eyes. Ask everyone you can to take a look and tell you what they see... Thats what I do. I dont hint towards anything. I just ask, "see anything wrong in this area".

As for belt alignment, you may need to point that out, I guess.

EDIT: It also looks to me that the engine is cocked counterclockwise a bit.

 

[Denny]

A straight edge is better than the eye.

 

[JimD]

The timing belt looks to be a 5mm pitch and if that engine is 5hp or more then don't waste time on buying a new belt because the 5mm pitch will not handle it for very long it will tear out the cogs in the belt. 5hp and above you would want to moved up to 8mm pitch belt. When you take the clutch off the engine it will say Max-Torque on the drive plate.
Looking at the one picture of the clutch and pulley I can see your problem of the belt wanting to go towards the wheel. I don't think the crankshaft is parallel with the axle. You will have to twist the engine on the motor mount plate to get them parallel so the belt will ride in the center of the driven pulley which has no belt guides that are on the driver pulley.

 

[JimD]

To answer your other question, belts run snug while chains run loose. You don't want to put any tensioners on the belt because they generate heat and a belt HATES heat. The nice thing about a Briggs is the engine has 4 holes in the base for a 5/16 bolt and no elongated holes which helped to keep them aligned but if your motor mount plate has larger slots than 5/16 then that contributes to the engine getting cocked. You don't need the engine running to get your alignment correct, just get the back end on a box and spin the axle. Get tension on the belt and then snug one bolt in the back down and leave the other three finger loose so you can very slowly move the engine in or out as you spin the axle and watch where the belt wants to travel.

 

[hhuxxleyy]

Upon closer examination a crack has been discovered on the rear axle. All progress has halted until the crack can be welded because when we pick the wheel up vs when we set it down it sags due to the crack, causing the belt to immediately come lose. Do yall think just welding it will be enough?

 

[ezcome-ezgo]

Clean it up, weld it up, should be good. Could add some buttressing to improve the strength while you're at it.

 

[panchothedog]

Thats going to need a gusset of some sort to help reinforce your weld. Anything, as.long as it touches two parts of the frame to give it some extra strength.