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Old 12-10-2019, 04:15 PM
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Default Manco jackshaft orientation.

I have a Manco 435B that is getting a new jackshaft that I need some advice on. I've seen 2 or 3 people on here break the 5/8" jackshafts on these karts, and I don't want to be another. Some info, this kart relies on two 3:1 reductions, created by a 10t clutch driving a 30t jackshaft input sprocket, and a 9t output sprocket driving a 27t sprocket on the half axle, resulting in a 9:1 overall reduction. And no, it has a 3/4 diameter axle, so I can't easily put another sprocket on it. Plus the axle sprocket is in the middle of the kart.

My question is, should I run the clutch inboard, and have the axle chain on the outside of it, or should I run the clutch outboard and have the axle chain on the inside of it?

Quick stone age drawing, I hope it makes sense.
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Old 12-10-2019, 08:19 PM
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option A is what Manco picked
and I think it might be the only way actually to make it work.

the bearings for the jackshaft and axle are not on the same plane AFAIK, so the axle
sprocket (being closer to the wheel) has to be further out..
and to have a straight running chain there isn't any option but A.

jackshafts only fail LOONG after the jackshaft bearings have failed on that kart tbh..
and bad maintenance is not the same as bad engineering

So stick with what Manco did and you'll be good..

also the two spacers between the sprockets on the jackshaft are .125" so the sprockets are actually just 1/4" spaced.. no noteworthy difference in terms of leveraging torque really

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Old 12-11-2019, 07:27 AM
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Thanks, I'll run with A. I don't quite understand the bearing part. I'll add a few pics.
Axle:
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Jackshaft:
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The jackshaft is new from BMI karts, and I picked up the kart a year and a half ago with a predator and two other frames for $300. And I don't think the previous owner did any prep work on the paint, because the whole kart looks like that on the inside, and has about 20 runs on the outside. And I added the bullet connector on the kill wire, so I could plug it in where the low oil switch used to. It did come with a max torque clutch, but the po tried to run it without the jackshaft reduction (3:1 gearing with 15" tires), so it was pretty fried, and blue.

Any tips on how to get a bit more bite out of the brake band?
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Old 12-11-2019, 08:12 AM
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What kind of shape is the brake lining on the band in? Is it oil soaked or glazed up? It could possibly just be time to replace it. How about the short stretch of cable? Is it in good shape? It's not stretching too much from being old is it? Just a few things you can check.
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Old 12-11-2019, 08:34 AM
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It is pretty glazed. That and the drum is pitted. The cable is a little frayed, but it's not stretching much (a new one is on my list).
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Old 12-11-2019, 09:57 AM
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Well I think you found your problem!
I think a new band and drum are in order!
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Old 12-11-2019, 10:28 AM
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Quote:
Originally Posted by JTSpeedDemon View Post
Well I think you found your problem!
I think a new band and drum are in order!
It might be a good tip towards getting better brake response... it's hard to make worn out brakes work good without replacement of worn parts...
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Old 12-11-2019, 10:42 AM
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Ok, the band'll be easy, but I won't be able to easily replace the drum. It has one if the 1 piece drum sprockets, and the only ones I can find are #35 chain, not 420, which is what I have on all my karts and bikes (it makes replacing chains much easier).
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Old 12-11-2019, 07:33 PM
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if the drum is only slightly pitted, you can just get some double sided sticky tape
and glue in some sandpaper to the inside of the worn out brake band..
install, apply the brake slightly and turn the wheel..
a heavily pitted brake drum would need to be replaced though I'm afraid

435B uses a 420 chain throughout;
wheel has a 27T brakedrum/sprocket combo same as the 436C
it's available here:
https://www.gokartsupply.com/sprocket.htm#13407
(in case the page doesn't jump to the correct sprocket; scroll down, you find both the #35 and just below it the 420 chain)
correct brake band would be this:
https://www.gokartsupply.com/brakes.htm#1036
(part # 1036 in case it again dfoesn't jump to the correct one automatically)

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Old 12-11-2019, 08:09 PM
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The drum is only a little pitted Just enough to see. And at $60 it'll be a while before I replace it.

I never thought of wrapping the band in sand paper to fix the drum. I have both 200 (ish) oxide and 800 grit wet dry. I think the 200 would get rid of the rust pretty well. Should I leave it after the 200, or use the 800 to polish it? I also have plenty of scotch brite, I don't know if it would work on this, but it sure does polish up engine output shafts.
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Old 12-12-2019, 08:17 AM
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200 will probably be fine. You don't need to polish it. The new band will take care of that for you as it wears in. Knock the rust off and produce a good working brake surface if you can. Free of rust and mostly pits removed if possible. You know what you need. Clean and oil free. Acetone is a good degreaser as is denatured alcohol.
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Old 12-12-2019, 08:22 AM
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Wait, you have one of the assemblies with the drum, sprocket, and axle hub integrated? They're only like $20....
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Old 12-12-2019, 08:33 AM
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Where? I've found one for $40, but it was for #35 chain, I'm running 420.
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Old 12-12-2019, 09:04 AM
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Ohhh, #420 chain. Yeah the one I was thinking of is from BMIKarts and it's for #35 chain.
Here: https://www.bmikarts.com/product.asp?itemid=10897
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Old 12-12-2019, 09:15 AM
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That sprocket wouldn't work, not only is it #35 chain, but I'd have no ground clearance.
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Old 12-12-2019, 09:30 AM
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There's a 60T one as well for about $20:https://www.bmikarts.com/Sprocket-60...m_p_10940.html

If you ever wanted to change to #35 chain. However it does not have an axle hub, so there's that.
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Old 12-12-2019, 09:34 AM
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Yeah, I like having the same chain on everything. That way I only have to keep one size masterlink on hand.
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Old 12-12-2019, 06:05 PM
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yeah JT.. but 60T is a terribly long way from 27T
the 435B had a 27T axle sprocket brake drum combo
(NOT two seperate parts on one hub as the 713's had.. but a single sprocket/drum combo)

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Old 12-12-2019, 06:08 PM
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Wheelies!!
Yeah no, bad idea to put a humungo sprocket on there and expect everything to work just right.
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