Reverse gear sprocket question ???

[Numbers]

What I have is an 18 tooth sprocket reverse gear box compatible with a 40, 41, or 420 chain.

What I need is to substitute a 16 tooth sprocket that matches the inner diameter of the 18 tooth sprocket and has the same bolt circle and is for a 530 chain.

Have one 16 tooth sprocket being shipped after carefully going over dimensions with sales. Will there be any further problems ? Besides the spacer issue between the case and gear box which will require minor modification to ensure proper alignment of chain from drive to axle.

Here is the new gear box I have;

[img]http://www.*************/assets/images/200680.jpg[/img]

Here is the sprocket I will be using;



It is a new replacement engine that has been waiting for the right moment to go in along with a host of other parts that I have been collecting to put in there. Only when I had everything on hand and prior mods done (welding, etc...) did I begin the journey of assembly. Now I've taken a detour and learned a somewhat expensive lesson in buying Chinese parts.

Will include pics once downloaded from phone.

[liduno]

I could be wrong but it looks like the only issue would be the bolt pattern. If you had them measure everything and the bolt patter is good then you should be good to go.

If you go too small there is a clearance issue with the head of the bolts and the chain but it doesn't look like you are even close to having that problem.

What was the expensive lesson you learned? Chain pitch?

[Numbers]

Verify everything before buying a reverse gear box. Could have been an expensive lesson is how I should worded that. As it was it still cost me a little over 20 dollars and I hate spending money on something that should have and could have been prevented with a little more diligence.


Pitch, roller width, diameter, chain number, shaft size, spline count, etc....

I'm learning alot from previous posts here that would have saved me this issue. That's why I asked if there was something else I might have missed.

[liduno]

Lets hope the reverse gearbox itself is as strong as one that comes with a 530 sprocket. And make sure your idle is low enough to disengage your clutch before shifting gear.

[Numbers]

Originally Posted by liduno

Lets hope the reverse gearbox itself is as strong as one that comes with a 530 sprocket. And make sure your idle is low enough to disengage your clutch before shifting gear.

After popping both covers off they both appear to have the same amount of meat on their splines, but without applying power to the ground I won't know unless someone else has did this before.

How much power would be required to grenade one of these gear boxes ? It's only a mildly modified gy6 that probably doesn't put out much more than a stock motor.

[liduno]

I think most failures are do to people shifting while moving or while their idle is too high. It's designed to shift while nothing is moving, if your idle is up too high and your belt is trying to move when you shift it will put more force on it before it is totally engaged.

[Numbers]

Thanks. Once fire has been made, I will check the idle. I'll keep my fingers crossed and maybe I won't blow nothing up...

[Numbers]

16 tooth sprocket installed. Bolt circle matches up perfectly. Matches chain. However, chain is not lined up , sprockets not lined up. New spacer for gear box is too narrow and old spacer is too wide. Both have an inside diameter of appx 20 mm. Is the best approach trying to find a correct sized spacer, use something like thrust washer with same ID, or grind the larger one / file carefully ? OR is there an option I am failing to consider ?

[liduno]

Cant really say for sure without actually seeing the set up, but my first thought was to add another washer.

[Numbers]

Originally Posted by liduno

Cant really say for sure without actually seeing the set up, but my first thought was to add another washer.

Thanks.

It appears that a 3 / 4 washer from Lowe's measures 20.80 inside diameter and was 3.22 mm thick. It fits and the sprockets are in perfect alignment. The chain rotates smoothly.

Thanks to Tom also.