Loose Chain

[qtband]

Look at my pic.
Why is it when you "flex" the kart at the swingarm, the tension on the chain loosens? Is it because of the positioning of the axle (red arrow) and the jackshaft (yellow arrow)? I don't want to use a chain tensioner, so what can I do to solve this issue. Move the axle?
Ken

 

[Iron John]

I don't understand. Aren't the engine, jackshaft, and axle rigidly mounted and the entire assembly swings as a unit?

Is your swing arm flexing?

Unless I am mistaken, something is rotten in Denmark.

 

[bob58o]

Are the wheels trying to turn when you flex the kart on the ground?
Causing one side of the chain to get tight?

 

[mckutzy]

It almost seams like something is bent, like one of the shafts are.

 

[qtband]

Everything is rigidly mounted. I wonder if my swing arm is flexing. I think I will take off the shocks and see if it still happens.

 

[OzFab]

Wait, you have the brakes mounted on the jackshaft?

 

[chancer]

Wait, you have the brakes mounted on the jackshaft?

Ooooh nice catch. OP that is wrong cause if your chain breaks, or slips off a sprocket or loses a master link.
YOU HAVE NO BRAKES!

 

[qtband]

Wait, you have the brakes mounted on the jackshaft?

Yes, I do. Good for you! But....you caught this about 5 years ago when I built this kart. I used it around the yard and had a lot of fun, but most of the fun for me was building this first kart. I let it sit for a long time and I'm back working on it. After I get it running again, I'll put a rotor on the axle and fab up some hydraulic brakes. First though, I have to solve the issue with the chain.
Ken

 

[OzFab]

Oh, did I?

Ok then, to adjust the jackshaft to axle chain, you need to move the jackshaft; then you need to adjust the engine accordingly...

 

[qtband]

Oh, did I?

Ok then, to adjust the jackshaft to axle chain, you need to move the jackshaft; then you need to adjust the engine accordingly...

Can't I move the axle? The engine and jackshaft is a b***h to move and align.

 

[OzFab]

By all means, if the axle is adjustable, go right ahead...

However, if moving the axle involves cutting off & rewelding bearing hangers, I would think moving the JS would be the simpler solution...

 

[qtband]

By all means, if the axle is adjustable, go right ahead...

However, if moving the axle involves cutting off & rewelding bearing hangers, I would think moving the JS would be the simpler solution...

Since it is a snowmobile engine, I need to maintain the correct distance for the jackshaft from the engine. I used the original snowmobile mounts and they are welded in place. I only have one welded hanger so that will be the easiest route for me.
I'm hoping that by lining up the axle and jackshaft, I won't have the chain issue.

 

[mindymogul]

On the subject of chains it seem like very time I rip mine around the track the axle sprocket actually slides about 1/4" to the left EVERY time I ride it for about 10 mins. What I don't get is the axle is drilled for the set screw and it never seems to back out. It's a hex axle so it can't be slippage.

 

[chancer]

On the subject of chains it seem like very time I rip mine around the track the axle sprocket actually slides about 1/4" to the left EVERY time I ride it for about 10 mins. What I don't get is the axle is drilled for the set screw and it never seems to back out. It's a hex axle so it can't be slippage.

Me too, me too! This is a hijacking!!

I thought the word fabulous was verboten?

Hijack much?

What they said^

 

[Sinbad001]

If your outboard axle bearing hangers are slotted (adjustable) , I would do like you said and just cut the center one off. Since your axle sprocket is outboard of the bearing hanger, the center bearing isn't doing much of anything. Another option is to make a separate sub frame for the axle which then bolts to the swing arm with slotted holes for adjustment. This is how my kart is set up.

 

[qtband]

Well, I moved the axle back and I still have the same issue. It must be in the geometry of the set up. I'm going to move the axle back to its forward location and add a chain tensioner. What side, front or back, do i install it?

 

[bob58o]

I'm still lost. Something has to be moving in relation to something else????
With everything mounted rigid, what is moving???


Does the chain fall off?

This type of question bugs the heck out pf me, like the chain that kept growing an inch every 5 minutes LOL!

---------- Post added at 02:46 PM ---------- Previous post was at 02:45 PM ----------

Are all of the sprockets tightened with keys?
Something bent or cracked?
Is the chain kinked?

 

[qtband]

Yes, if you accelerate and hit a bump, the chain will pop off.

 

[Sinbad001]

Based on your picture your axle needs to move forward in vehicle to tighten the chain.

 

[Grape Ape]

It looks to me as if the jackshaft may be flexing, how is it supported?