My First Kart Project

[Stratogeezer]

Hey Nerfo,

My 96 tooth sprocket arrived today and I installed it tonight. I thought I'd ordered the 2 piece kind, but it was a a one-piece, so I had to pull the axel assembly off, pull the old one off and put the new one on...and put it all back together.

Anyway - it's pictured here. It's too rainy tonite for a test drive - but maybe tomorrow we'll see what kind of torque difference I see with this bigger sprocket, versus the old 72 tooth. I calculate it should have a top speed of about 20mph - which is fine by me....as long as it gets me up those hills.

 

[nerfo]

I think you'll notice a big difference in get up n go with that bigger sprocket on there! Not to mention how much easier it'll be on the clutch in the long run. I'll be happy with mine if it has a top speed of at least 30... I've punched the numbers into the calculator here and it keeps coming up with about 40. When it stops raining later (rats!) I'm going to drive it and see how it does and I'll verify top speed with a Garmin. If you don't hear from me within 8 hours, assume the test drive went horribly wrong!

 

[nerfo]

Well, I took 'er out for a short drive today to see how it did... not too bad! According to the GPS it hit 37.8 MPH, but there was an odd noise coming from the engine and I was afraid to hold my foot to the floor any longer... turns out the noise was just the snap on plastic cover over the TAV vibrating like crazy.

Unfortunately, my fun was cut short when I noticed one of the bolts for the gas tank vibrated its way out and the tank was too loose for comfort. Oh well, new bolt and some loc-tite.

The TAV and big axle sprocket really gets that baby moving in a hurry! I'm going to have to put the spring into either hole 2 or 3 because it begins shifting too early and is completely in the highest range before it's even going 20. So, some tinkering and adjusting will be in order. But the acceleration from a dead stop was very satisfing! It pulled surprisingly well!

Unfortunately, I didn't get a video... I forgot my camera. But as soon as the weather is nicer (it was cold and rainy today) I'll take it out again and have someone shoot a video.

 

[Stratogeezer]

Awesome, Nerfo - that thing really hauls. That is much faster than I'd have assumed it would go - but hey - nice to have that speed. The first few times out of the garage all kinds of odds and ends adjustments are necessary as I've experienced as well. 2nd time out I lost my breaks when the cable detached itself - with no harm done.

I didn't test my big sprocket yet....too much non-go kart activity filled my weekend. I'll take it out one night after work this week. Let's see some video of yours in action!

 

[nerfo]

This is just a really short video of the go kart hauling up the street and back... might have crabby neighbors and, well... crabby neighbors are unpleasant neighbors! I'll get more video when I can get it somewhere outside the neighborhood once all the ground around here finally dries up... it's still pretty mushy.


http://www.youtube.com/watch?v=14BTp_kMTM8

 

[nerfo]

That's whats fun about these things... ironing all the kinks out. I really have to adjust the clutch on mine so it "shifts" later. It's all the way into high range way before the kart is really moving good and the engine kinda lugs. I'd like to rev a bit more freeley under load. It also takes a LOT of road to get that thing going anywhere near 40! But, I'd rather it have the power to get going and move itself around eaisly... top speed is nice, but oomph is what I'm after!

 

[bugatti_gokart]

http://www.northerntool.com/webapp/...06_17806?cm_sp=RVC-_-Category Page-_-Products

Totally forgot the link! Sorry dude! Well, I'll see how they hold up. They fit on the axle pretty well, and the only thing I can figure would break them would be some REALLY hard landings (I dont PLAN to ever jump this thing, but, hey... gimme a beer and this baby might fly!) or excessive side loading due to a hard hit to the side of the wheel (like hitting a curb in the middle of a donut) I'll see how they do, and if one ever does break, I might just consider gusseting them. Thanks for the idea!

What wheels are you gonna use on this baby? You're off to a great start for sure.

Jas

 

[newrider3]

What wheels are you gonna use on this baby? You're off to a great start for sure.

Jas

Never bothered to read the rest of the thread, eh?

 

[Stratogeezer]

That's whats fun about these things... ironing all the kinks out.

Well - I'm with you there to a point - but I'm ready to move beyond tweaking and into some more riding.

I just took the SG Kart out for it's first test drive following the sprocket transplant. Good news - much more torque. In fact when I press the gas pedal hard enough it pulls so hard it compresses the shocks.

Bad news is I can't seem to keep the chain on. I think it's aligned - but it's like the clutch and the #35 chain don't seem to mesh correctly. It seems to be somehow "catching" at intervals.

Oh well - great video of your kart Nerfo. Neighbors can be a pain. Mine just look at me like I'm a nut, but I doubt any truly seem to care enough to call the FBI on me.

 

[nerfo]

I actually had one neighbor lady call the company I work for becasue my work vehicle (with company logo all over the side of it) was parked on the street, along the curb, which is perfectly legal to park on... in front of her house. She called my office and complained that because my van was parked infront of her house, it was blocking her mail box and the post office wouldn't deliever her mail... which supposedly contained perscreption drugs. Well, they must be some darn good drugs, because the mail gets delivered between 2 and 3 pm, and if I'm ever home before 4:30, it's saturday or sunday. So, she's been a thorn in my side and just WAITS for someone over here to have a party or let even the tiniest bit of noise escape after 10 pm. But, this is my side of the story... so, it's skewed in my favor (that she's nuts) But, I'm pretty sure she is, because I don't think they mail drugs.

And for Bugatti... Umm, using the ones in the pictures? Lol! On page 2 are the pics of the kart and there's a few with the wheels and tires... I have no idea what they're called, but they're golf cart wheels of some sort.

 

[dcook3333]

Read the comment a few posts back on the chain "catching". It's either really catching on something or it's skipping which is a little different. Take a look at your master link as those stick out to the side the farthest. Put it up on a block and spin the tires while pushing the chain left then right because a chain has a little room to move side to side. If you can't find what it's catching on, then it may be skipping. If the chain is not loose, then it may be flexing the axle, motor mount, or TAV mount. To check for this, squeeze (hard) the 2 sides of the chain near where they meet the drive sprocket. If there is flex in your system, then you will see it when you squeeze. On my cart with the 16hp, I'm making enough power to make my axle flex and had to put an extra bearing on it.

 

[Stratogeezer]

Read the comment a few posts back on the chain "catching". It's either really catching on something or it's skipping which is a little different.

Well - I put it up on jack stands and spun it - and the chain catching seemed to have stopped. So I took it for another test drive - and right as I hit the bottom of the driveway, the chain popped off again.

I think it may just be too loose. It may be too hard to tell how much play I have in these photos below - but when the back end bounces around there is enough play where it could simply be coming off because it's too loose. It's not enough to take out a link - so I'll likely need to move the engine forward and try tightening it again, making sure I keep it aligned. I think I've spent more time messing with this chain and sprocket issue than anything else so far - but I'm not defeated yet!

 

[dcook3333]

Then it's probably just loose and popping off... that's a long chain. Your engine mounts should be slotted to allow you to move it forward and tighten the chain. If you've moved it all the way to the front, then it's time to remove a link (or half-link) from the chain. It looks like all your sprockets and chain are new. When everything is new, it takes some time to break them in... This is when the chain will "loosen up" quickly. You should be okay once there is a few miles on all the stuff. If this continues to be a problem for a long time, then may want to consider putting a tensioner in the system. That's just an idler sprocket mounted on a pivoting bar with a spring. Sorry to Nerfo for hijacking his thread. How about if the chain thing continues to haunt you... let's start a new thread??? BTW - great video of the test drive - there's nothing wrong with that krate - just run it!

 

[Stratogeezer]

Hey - thanks again dook3333. I'll switch my chain issues to a new thread if they continue.

And Nerfo - I agree - your kart is awesome....sounds like you just need some new neighbors! Especially that one old bag. There's always one....

 

[nerfo]

Don't worry about hijacking... I'm having some of the same issues as Strato, so it doesn't bother me! I did notice that after even a short drive, the chain on mine got loose really quick too. The motor isn't sliding back on the mount at all, so I know it's the chain kinda streching a little and settling into the sprocket. My clutch sprocket is only probably... 5 or 6 inches away from the axle sprocket, so I don't think it has the chance to jump off. I did notice that these big sprockets don't appear to be mass produced, and the chain is a REALLY tight fit at first.

We're looking at REALLY crappy weather this weekend... snow and everything. But snow always come with the UW Wisconsin Mens Basketball Tournament. It's weird.

Anyway, thanks for the words guys! Now that I know where my odd kinks are and most have been ironed out, I'll probably break it down and paint it all up. Yeah, neighbors can be a pain, that's for sure. I'll get some better video with it out at my folks house (dead end road, middle of nowhere, long driveway to boot!)

Actually, does anybody following this know how to get the outer hub dealie off the driven part of a TAV30? I want to move the spring to a higher number hole so it changes ratios slower/later. I removed the nut and snap ring (nut back on in pic to keep the whole thing from sliding on the shaft) but I can't pull it off with my hand. I thought about a 3 jaw puller, but I don't wanna reef on the aluminum and booger it all up. Any thoughts? Or is the puller the way to go?

 

[Stratogeezer]

Thanks Nerf - wish I could guide you on that TAV, but I opted for the garden variety centrifugal clutch. However - that question would get answers probably immediately as a new thread by some of the more experienced guys.

I had a breakthrough last night with my sprocket. I had my engine mounted on those goofy rubber grommets that they sell @ Norhern. I removed them, snugged up the bolts and tightened the chain nicely by tapping the engine forward.

So I took a quick blast around the neighborhood to test it, in the pitch dark while holding a flashlight. Yessssss....the chain stayed on!!!

That 96 tooth sprocket provides major torque and plenty of top end speed - both of which I've yet to fully explore. But not that I can actually keep the chain on...I'm in business.

 

[nerfo]

The worst thing about wanting to test something, is when you're ready to test it at the worst time... but after five minutes of debating with yourself, you say, "SCREW IT! I'M DRIVING IT NOW!" Hilarious! I'm glad your test drive went well!

I actually think using a larger sprocket with a typical, unmodified, industrial engine allows you to take advantage of the whole RPM range of the engine. You might loose a bit of top speed, but that's only if the engine had the power to reach its maximum goverened RPM with a smaller sprocket. It's rather uncomventional thinking, I know... but from a fun point of view, I'm rarely having the most fun going full speed... I'm having the most fun doing dumb stuff at slightly lower speeds! I like having that bottom end grunt to really get things going!

Well, I did monkey around with that clutch last night, and as it turns out, that... hub thing... is just a snug fit on the driven sheave. I used a puller and the hub slid of the sheave with realitive ease. Getting it back on with higher preload - that was a different story! So, as soon as it warms up, I'll have to take it for another drive and see if the clutches shifting acting has been delayed the way I'd like it to have been.