Gear box

[kevbo22]

Last year I swapped out the 150cc on my minibuggy with a 420 predator. I just ended up replacing the entire rear swing arm. The old swing arm didnt really have suspension because of the way it was designed. It was really just for show, the swing arm had a rubber stop at the top of the motor mount. You can see the new one here:http://www.diygokarts.com/vb/showthread.php?t=28874

Anyway, Obviously by doing this I lost the F/N/R. So I have been looking around for a new gear box. I had purchased a comet gearbox but didnt like it at all. Never even attempted to use it. I ended up selling it to kartfab. (hope he got good use from it).

A few months ago I purchased a new gearbox from ebay. I really like it. But it was made for a 30 series and the input shaft wasnt long enough for any pillow blocks. It was also a 5/8" input shaft with a key that was made for a TC that didnt have a built in key.

I had the input shaft remade to a 3/4" with a keyway made to fit my 40 series TC and long enough for pillow block support (as seen in the pic)

Overall, I really like this gearbox! I like the way the shifter knob controls it. It also has a "pressure hole" in it like the bigger more expensive gearboxes. I couldnt find much info on it online, but taking it apart to have the input shaft remade it seems the gear ratio is 1.3:1. I think it is from the trailmaster go karts.

So far I really like it! Havent put it to the test yet but I'll keep you updated. So if you're ever in the market for a F/N/R gearbox, I give this one a thumbs up for sure and they are not too expensive.

 

[chancer]

Do you have a link to this part... You said ebay but...
What brand is it? Where can we find it?

 

[kevbo22]

Do you have a link to this part... You said ebay but...
What brand is it? Where can we find it?

I did get it on ebay. I dont know what brand, but BMI does stock it sometimes. When I bought mine BMI didnt have any, and didnt know if they would get any back in. But it looks like they may have some now: http://www.bmikarts.com/Go-Kart-Forward-Reverse-Kit_p_3680.html

 

[2SlickNick]

Will that gear box handle the 420cc ?
I have seen people use Polaris 4 wheeler gear box and cvt system.

---------- Post added at 01:11 AM ---------- Previous post was at 01:10 AM ----------

Oh and the build looks great too...
Any vids of it?

 

[kevbo22]

Will that gear box handle the 420cc ?
I have seen people use Polaris 4 wheeler gear box and cvt system.

---------- Post added at 01:11 AM ---------- Previous post was at 01:10 AM ----------

Oh and the build looks great too...
Any vids of it?

Ya, I am pretty sure it is going to be fine. I saw a twin arachnid build on this forum use the comet gearbox with a 420 and gov removed and it held up. I personally think this gearbox is a better build quality than the comet. Also I had the input shaft remade a little stronger and it will have two pillow blocks to support it now, that will make a huge difference.

But like I said, I havent put it to the test yet. I will post again about it after I install and ride quite a bit.

I do plan on getting some video this year that I will post. I really want to get video of it next to a 150cc for comparison.

 

[tazmannusa]

How is the gear box working ? installed yet
I just ordered one myself, going to try it out with 6.5 HP with the 30 series

 

[kevbo22]

How is the gear box working ? installed yet
I just ordered one myself, going to try it out with 6.5 HP with the 30 series

No havent found the time to put it in yet. But I will be doing it here soon and will post back here. Feel free to post here when you get yours in.

 

[tazmannusa]

Just my luck , Received it today , spin the input shaft by hand there is a binding spot, pulled the cover off and didn't see any thing that looked bad so bolted it back on and installed the driven, filled it will gear oil and the same, shift doesn't feel solid and spinning it slow by hand hits a bad spot and binds it up. spin it quick and it will go past the bind

 

[kevbo22]

Just my luck , Received it today , spin the input shaft by hand there is a binding spot, pulled the cover off and didn't see any thing that looked bad so bolted it back on and installed the driven, filled it will gear oil and the same, shift doesn't feel solid and spinning it slow by hand hits a bad spot and binds it up. spin it quick and it will go past the bind

Return it for a new one, mine doesn't do that at all!

 

[tazmannusa]

Return it for a new one, mine doesn't do that at all!

Not looking so good , sent an email to BMI about it and what it was doing. Response was it was forwarded to the manager and he said it was ok that it was because I was turning it by hand that it was designed to be hooked to an engine then I was refereed to the return policy 30% restocking fee plus I pay for shipping.
I did respond and tell them it was not ok there was something wrong
with it and I just want a good one and ask do I have to pay shipping for both ways and hope I get a good one. We shall see what they say about it . ether way looks like I have to fork out more money or I am stuck with a bad gear box

 

[kevbo22]

Not looking so good , sent an email to BMI about it and what it was doing. Response was it was forwarded to the manager and he said it was ok that it was because I was turning it by hand that it was designed to be hooked to an engine then I was refereed to the return policy 30% restocking fee plus I pay for shipping.
I did respond and tell them it was not ok there was something wrong
with it and I just want a good one and ask do I have to pay shipping for both ways and hope I get a good one. We shall see what they say about it . ether way looks like I have to fork out more money or I am stuck with a bad gear box

Man I hate hearing things like that, especially because I started this thread saying it was a good one. Open in up and snag some pics, I can compare to mine if you want. Maybe its not really all bad

 

[tazmannusa]

Sounds like a plan, I will wait for there response first. It feels like a bad pin or link in the chain.
Don't feel bad about it, I have noticed that stuff coming from china some times is good and other times not so good. You mentioned you had bought a comet to start with but didn't like it , what was it that you didn't like ? Just not much info out there on them

 

[kevbo22]

I didnt like the way it shifted, and I didnt like the way it was set up to shift either. One reason I really liked this one right off the bat was it was set up to shift with a cable equalizer. It shifts gears smooth, the comet had to be in just the right spot or it wouldnt shift. You would have to kind of move the shaft forward or reverse to make it hit the "sweet" spot to shift. I saw a youtube video of that comet box with the same problem. I also didnt like how the comet was mounted.

But Ill watch to see if you post pics and will post mine to if you do. If it is chain, I remember it being 420 chain.

 

[tazmannusa]

I didn't here back from them so I guess I'm stuck with it or pay shipping both ways plus maybe a 30% restocking fee because they say there is nothing wrong with it , that would be ether exchange it or return it. Any way I disassembled it , all parts look good to the eye, reassembled with side cover off spinning it there is one spot that the chain and main gear are really tight. Tightened the detente spring a bit bolted it back together and filled with oil, now it feels better in forward , neutral gets a little bind , and reverse will bind up hard enough that I cant hardly turn it. shift part feels better. I think one of the shafts, sprockets, or gears was machined a little out of round causing it

 

[KartFab]

Anyway, Obviously by doing this I lost the F/N/R. So I have been looking around for a new gear box. I had purchased a comet gearbox but didnt like it at all. Never even attempted to use it. I ended up selling it to kartfab. (hope he got good use from it).

Currently collecting dust. Its going on a 13 hp gx390 powered mini buggy soon ... err i mean sometime before i die in the future that is distant.

tazman, did you pay with a credit card or paypal? If you payed with paypal you are in a good position, if you paid with a credit card you are in a better position.

paypal: immediately file a claim and say item was not as described/damaged, and the worst that can happen is you pay return shipping, or nothing happens at all.

card: go to your credit card statement and file a chargeback claim with your credit card provider. Tell them that you got it damaged and the vendor will not replace it at no cost, see what they can do. Its amazing what a vendor will do that screws you over once they find out they arent getting any of your money until it is fixed. Keep in mind that you may have to pay for shipping.

If you paid through paypal, but paypal took the funds from yoru credit/debit account, you still have chargeback rights, even if paypal says you cant do anything. I wish i had paid for a damaged engine block (unaware of this until i received it) with a credit card because paypal only said i could return it, not get a certain amount off for what it would cost me to fix some cracked fins. Seller was a complete douche.

 

[tazmannusa]

I payed with paypal from account, I could file but I don't think I would get to far. The old saying first time shame on you second time shame on me. Bought a lot from them in the last year or so , So I guess there not to interested in my business.
I am going to take it apart again and dig out the v blocks and indicators to find out if it's something I can fix it or not.

---------- Post added at 03:30 PM ---------- Previous post was at 02:33 PM ----------

Found the culprit all is good except the 13 tooth internal sprocket, two teeth were machined a little off causing chain bind, tried a round file on it but it has been hardened so the file wont hardly scratch it

 

[mckutzy]

A sharpening stone or diamond home will help... Usually harder than the gear...
Go slow and use some lubricant, check fitting often as to not over doit.

 

[tazmannusa]

A sharpening stone or diamond home will help... Usually harder than the gear...
Go slow and use some lubricant, check fitting often as to not over doit.

I sent BMI an email so they know it's not OK, we shall see it I can get a replacement part
If not I will try your'e suggestion, I know I should be able to get the bind out that way but I would prefer to have one that puts the same pressure on each chain roller as there supposed to in both directions
Thanks

 

[kevbo22]

Worst case you can just buy a new 420 sprocket. But its still not right that you would even need to purchase a new one. Hopefully BMI comes through on this for you. If you have a fastenal near you I recommend them for a new sprocket. Free shipping to the store for pickup and like $8 sprockets.

 

[tazmannusa]

Wish I could use a standard sprocket but it has the dog clutch machined on one side