Started new build.

[utahoutdoors]

Stumbled on this today: http://m.ebay.com/itm/231205667264

Since the comet 40 kit comes with a gear attached to the
back plate. I would need to add another small jackshaft for the
driven and a 10T gear. Even with the cost of this kit, jack shaft,
bearing and a belt I would be money ahead.

 

[utahoutdoors]

Did I mess up on my calculations?

So my plans were to purchase the Series 40 TC with a 10T. So if the above info I was reading the comet install info from a link http://www.bmikarts.com/PDF/Comet_40series.pdf

Page one discusses the speed ration of 1:1 on the low 2.43:1 on on the high.

I used the calculations on a simple 10t with my other 2 sprocket with the one jack shaft
to give me a 8.12:1. Do I need to discount the torque convert ration range on my calculation which could give me 8:1 to 16:1 range?

If I need to make changes please let me know, before I order the 10T and torque converter.

Thanks

 

[crazykart]

Don't worry about the actual tc's gear ratio. The only thing you need to worry about is your fixed ratio.

The added torque from the fixed ratio combined with the TC will give you plenty of get up and go for those big tires and the terrain you want to traverse. While the higher ratio (what you call the lower ratio) will give you plenty of top end speed after you get up and go, and still be able to turn those huge tires on the terrain.

So just worry about your fixed ratio from the gears, not the ratio combined with the tc's ratio.

 

[utahoutdoors]

Thank you crazy kart.

I think I going go with comet knock off you posted on ebay. Even with another JS,
pillow bearing set, jack shaft and 10T for 3/4" I will save about $220.00.

Since I have more room than I was planning since I raised the engine up 5 inches when
I welded up the mounting bracket.

 

[crazykart]

You may want to contact the seller first and make sure that is a 40 series knock off and not a 3o series, just to be on the safe side.

 

[utahoutdoors]

You may want to contact the seller first and make sure that is a 40 series knock off and not a 3o series, just to be on the safe side.

I actually have exchange a few emails with the seller.

The driver is the 203015A comet replacement, the Driven
is 209133A comet replacement.

 

[itsid]

Did I mess up on my calculations?

So my plans were to purchase the Series 40 TC with a 10T. So if the above info I was reading the comet install info from a link http://www.bmikarts.com/PDF/Comet_40series.pdf

Page one discusses the speed ration of 1:1 on the low 2.43:1 on on the high.

I used the calculations on a simple 10t with my other 2 sprocket with the one jack shaft
to give me a 8.12:1. Do I need to discount the torque convert ration range on my calculation which could give me 8:1 to 16:1 range?

If I need to make changes please let me know, before I order the 10T and torque converter.

Thanks

The 10T TC will be fine, the rest might be off though.

The general consens is in fact to get a gear ratio that will work with just a clutch, and then install a TC and be happy about the improved take off torque as well as uphill capabilities etc.

And, that is a very sensible way of doing it;
all good you can just proceed.

BUT:
You have an additional 2.43:1 ratio when you need it
provided by the TC;

soo, why not take a spoonfull of that extra and and use it to gain some more speed?

So personally, I'd say gear for 7.5 instead of 8.12;
and let the TC compensate for that (it will happily)
and not only have take off and hillclimbing capabilities improved, but gained almost 10% top speed as well

Without the exact weight and wheelsize of the kart
it's a pain to judge what'll work and what'll fail;

but basically if you're confident that 8.12:1 will work with a clutch, then I'm pretty sure 7.5:1 is still safe with a TC

(say 27 & 28 teeth instead of 28 & 29 for example to get 7.56:1)

'sid

 

[utahoutdoors]

The 10T TC will be fine, the rest might be off though.

The general consens is in fact to get a gear ratio that will work with just a clutch, and then install a TC and be happy about the improved take off torque as well as uphill capabilities etc.

And, that is a very sensible way of doing it;
all good you can just proceed.

BUT:
You have an additional 2.43:1 ratio when you need it
provided by the TC;

soo, why not take a spoonfull of that extra and and use it to gain some more speed?

So personally, I'd say gear for 7.5 instead of 8.12;
and let the TC compensate for that (it will happily)
and not only have take off and hillclimbing capabilities improved, but gained almost 10% top speed as well

Without the exact weight and wheelsize of the kart
it's a pain to judge what'll work and what'll fail;

but basically if you're confident that 8.12:1 will work with a clutch, then I'm pretty sure 7.5:1 is still safe with a TC

(say 27 & 28 teeth instead of 28 & 29 for example to get 7.56:1)

'sid

Thanks Sid,

I think I will order a 27T as well so I can get that 7.5:1 with
the jack shafts. That way I have some gears to fool around
with on different torques.

BTW: The weight of this kart/buggy is about 250. With 22" tires and the 13 HP, 420CC.

Torque is more important to be honest than +10% speed as well mess around with the jeep RV in the Utah mountain, desert and sand. Below you can a few of the area in our area we like to visit.

 

[utahoutdoors]

I received my TQ Series 40 last week. It been sitting there for over a week in the box. But lost my dog suddenly and been
hard for me to work in the garage without her. Finally got the
urge to get out there. Well for some reason did not expect
that driver and driven to be so big. The driven I think is 7.5"
across....

Lucky I have lots of room on my kart/buggy to put the
new jack shaft.

I ordered a new 27T and another 10T. They shipped the 27T but not the 10T... Some how they forgot to put it the shipment

So I guess another week or so.

So now with the 27 and the 28T with the 10T I get about 7.56:1
ratio.

 

[Lucky7]

Sorry about your dog. Those are cool places to go on a kart.

 

[OzFab]

So now with the 27 and the 28T with the 10T I get about 7.56:1
ratio.

Correct

 

[utahoutdoors]

When planning for the TQ belt size question. When you measure from center to center and it right in between 2 measurements. To you purchase the lower or higher size?

Thanks

 

[OzFab]

Last time I checked, each belt covers a range of measurements; if your measurement is on the cusp of two belt sizes, my first thought is to move the J/S slightly (which ever way is more suitable) until you're inside a range...

 

[utahoutdoors]

When I looked at several for Series 40 I did not see a range.

http://www.mfgsupply.com/gomini/gom...miniclutchtorq40/gominiclutchtorq40belts.html

So not sure for example when using 7.5" driven does the 203789A which has a rating
for 10 1/2" ... Is that measurement the bottom end or high end of the CD measurement for my configuration.

 

[utahoutdoors]

As I a preparing to install my JS X 2 for the TQ and gearing I noticed online pictures. Some have the spring away from the
engine and others have toward. I could not find any wrong or
right answers on this one. Since the force of the belt will be putting force on the one side of the spring as it tightens at
will cause the JS to engage. Thus the 10T with the chain to
engage.

Here a pic of my kart setup.

 

[utahoutdoors]

I am not sure what the problem is. I have a 3/16 key to go on my jack shaft which slides in fine. But the key doesn't go into either sprocket or the key slots on the pillow bearings.

Any ideas?

 

[OzFab]

Bearings don't usually have a keyway...

Double check the size of the keyway in the sprockets, you may need to open them up slightly or, at least, clean them up...

 

[briggsandstratton123]

is the 420cc motor a clone?, how much horsepower does it make

 

[utahoutdoors]

is the 420cc motor a clone?, how much horsepower does it make

I do have the clone, which states at a 13HP.

---------- Post added at 11:33 PM ---------- Previous post was at 11:30 PM ----------

I have ordered the azusa 27,28 & 29 all #40 chain. The 29 T goes fine
with the #40 chain. But the 27T seems to be off. I double check the order from the
paper work for a T5315-27. Which says it for a #40... Any ideas?

 

[utahoutdoors]

OK finally got tired of the cold garage and sucked it up and went back
out to work on the kart this weekend.

I got the 2 chains installed and the TQ belt. I have included some
pictures of the setup of the belt and need some input on it if it too
tight/loose etc.

I have not taken it outside to fire up the engine to test due to the cold.
Its 24F in the Garage and 9F outside with a mess of snow to deal
with.