Interesting design

[Doc Sprocket]

Spotted this, cruising the local ads. Pay particular note to the independant rear suspension. Can't see enough of it, but I have emailed the seller for more detail. I'm also trying to find out if these are going into production, or if it's a one-off... or what?

http://toronto.kijiji.ca/c-cars-vehicles-other-2012-ruli-kart-made-in-Canada-W0QQAdIdZ381123475

 

[ӍДҬӍДҊ⑤⑤]

that thing is sick!!!it almost looks like a sandrail.

 

[Doc Sprocket]

It's interesting. I think the seat design, including the roll-hoop-looking-thing kind of looks like an afterthought. Maybe after all the suspension stuff was hammered out, the builder didn't wish to put too much into that aspect. Other than that, looks like a great ride. I'm hoping the seller gets back to me with some details.

 

[ӍДҬӍДҊ⑤⑤]

It's interesting. I think the seat design, including the roll-hoop-looking-thing kind of looks like an afterthought. Maybe after all the suspension stuff was hammered out, the builder didn't wish to put too much into that aspect. Other than that, looks like a great ride. I'm hoping the seller gets back to me with some details.

ide deffinetly buy one if they were production and at a good price.i would definetly have to fix the whole seat thing.

 

[Doc Sprocket]

I just recieved this from the builder/seller:


"Hey Chris,



Thanks for the interest. Yes, I know your website and it did help me get started. The go kart was designed and built by myself as a proof of concept. I am a recent mechanical engineering graduate and currently enrolled with graduate studies. This project took about 3-4 summers to complete on a hobby basis, from experimenting with wooden frames and lawnmower engines to what the product is today.



The rear independent suspension is indeed unique. Having a differential drive with CV joints is the universal standard for such suspension systems, yet none were used due to cost and weight considerations. To maintain sprocket alignment, there were two main things to minimize. First, it's the track change (distance between wheel and chassis) when hitting a bump. This is minimized by having the longest links possible. Second, the angle difference between chassis roll and wheel camber during a turn. This is minimized when the links are level to the ground when a person sits in the kart (done by adjusting spring preload). Carroll Smith's "TUNE TO WIN" explains this very well. For the current setup, a maximum chassis roll of 2 degrees including bump conditions will result in sprocket alignment within about 0.7 degrees. Under the same conditions, track change may be up to 1/4in. These maximum limits were found to be satisfactory at the current sprocket-to-sprocket separation for a #35 chain. Other factors to consider include linkage deformations, vibration and toe-in compromises.




Doing stuff yourself is always insightful, but it also rationalizes some of the magic and awe around it!



Thanks again,

Dmitry"

I asked him for more info, and even invited him to join. I'd like to see more. The whole seat thing is peanuts- easy fix. But I am dying to get a better look at the suspension!

 

[exenos]

One thing I noticed is that it's only one wheel drive, or at least that's how it looks.

 

[dmaznic]

Thanks everybody! This is my design. In all honesty, the seat was an afterthought and made from a couch cushion by my mom haha This site was very influencial for me when I found my first lawnmower engine on garbage day and didn't know what to do with it.

It is indeed a one wheel drive with three wheels for braking (foot pedal for front ones and hand brake for rear). This may limit its off-road capacity but the suspension was never really designed for it anyways. The clearance is about 2.5in with the driver in the car.

I'm currently trying to decide on the carburator main jet. When the engine was stock, the plug reading was a perfect tan brown. Now I installed a high flow air intake and exhaust which may demand more fuel. The problem is that my neighbourhood is bad supplying this kind of stuff and it's difficult to find small enough srill bits to modify the stock main jet myself.

Any questions/comments/concerns about the go kart are always welcome!

 

[Bluethunder3320]

Thanks everybody! This is my design. In all honesty, the seat was an afterthought and made from a couch cushion by my mom haha This site was very influencial for me when I found my first lawnmower engine on garbage day and didn't know what to do with it.

It is indeed a one wheel drive with three wheels for braking (foot pedal for front ones and hand brake for rear). This may limit its off-road capacity but the suspension was never really designed for it anyways. The clearance is about 2.5in with the driver in the car.

I'm currently trying to decide on the carburator main jet. When the engine was stock, the plug reading was a perfect tan brown. Now I installed a high flow air intake and exhaust which may demand more fuel. The problem is that my neighbourhood is bad supplying this kind of stuff and it's difficult to find small enough srill bits to modify the stock main jet myself.

Any questions/comments/concerns about the go kart are always welcome!

welcome to the forum! you put a ton of work into that kart nice work!

as for the main jet the usual size with a header and intake is #90. you could probably find one on ebay for cheap.

 

[Doc Sprocket]

Thanks everybody! This is my design. In all honesty, the seat was an afterthought and made from a couch cushion by my mom haha This site was very influencial for me when I found my first lawnmower engine on garbage day and didn't know what to do with it.

It is indeed a one wheel drive with three wheels for braking (foot pedal for front ones and hand brake for rear). This may limit its off-road capacity but the suspension was never really designed for it anyways. The clearance is about 2.5in with the driver in the car.

I'm currently trying to decide on the carburator main jet. When the engine was stock, the plug reading was a perfect tan brown. Now I installed a high flow air intake and exhaust which may demand more fuel. The problem is that my neighbourhood is bad supplying this kind of stuff and it's difficult to find small enough srill bits to modify the stock main jet myself.

Any questions/comments/concerns about the go kart are always welcome!

Hey- I'm glad I talked you into showing up... Welcome! When you've got a chance, toss up some more pics, would ya?

Anyways, listen- those drill bits aren't as hard to come across as you might think- I got mine from Princess Auto, and I believe they still carry them. He//, I can even get you stock numbers if you like- got a brand new catalog on my desk!

If drilling your own jets isn't for you (although it's not hard) you can buy them. Princess does NOT carry them, but you can get them from many suppliers. Your engine is a knockoff of the venerable Honda GX200- as such, jets for a GX200 will work.

 

[dmaznic]

Yes, can you please give me that number? Maybe what's confusing me is the numbering system.
#90 --> 0.0022mm diameter? I will take a look through the forums.

 

[landuse]

Have a look at this article on drilling jets. It also gives a chart of sizes

http://www.affordablegokarts.com/Drilling Main Jets.php

 

[dmaznic]

Yes, I've seen it many times before. It seems the jet size is not related to the drill bit size. Still, the smallest bit they show is about 1mm. A #90 jet is about 0.9mm. I have yet to find such small drill bits. I will try local small engine dealers and see if they can get me some jets to experiment with.

 

[r97]

Google search "numbered drill bit set", you will get plenty of results. Remember that when using these bits you should turn them by hand. If you can, place the bit a drill press then turn the chuck by hand.

 

[dmaznic]

just going to order a #88 and maybe a #90 from a Honda dealer ($5.65 CAD each) I don't know why, but everybody goes with #90, I would rather be a bit lean than rich, contrary to popular opinion haha

 

[kendelrk]

with an open filter and good exhaust a 90 jet provides just the right amount of gas, be warned tho. starting it cold is different because after the 90 jet it wont like the choke to much, but youll need to use it for cold starting. one of the best things about switching jets is no longer having to put the choke on to start a hot engine.

 

[bighead]

If you drill your jets use a flaring tool to hold the jet level. Works like it was made for it.

 

[Doc Sprocket]

If you drill your jets use a flaring tool to hold the jet level. Works like it was made for it.

Great tip! I just been using my fingers...

 

[dmaznic]

Thanks, I just ordered a #90 jet from Honda. It was one of three in Canada apparently, they will have to ship from Montreal. Kind of funny, shipping a tiny bolt across the province.

In any case, I was looking whether lean or rich is better. I am excited about easier cold starting with slightly richer!
http://www.randakks.com/TechTip72.htm

I have heard about main jet drilling, but nobody posts their results?
Does everybody end up with #90 anyways?

 

[Doc Sprocket]

#90 might be a decent ballpark number, but I caution you and everyone else against writing it in stone. As there are many variables involved with individual engines, you may well find that it's still not right.

Instead of ordering multiple jets and relying on hearsay, I drill my own. I have several pin vises and a LOT of numbered drills. It's a carry-over from one of my other hobbies- building 1/25th scale model cars and trucks.

Anyways, overdilling is a bit of a pain in the butt, but not the end of the world. When I was tuning my son's doodlebug, I found the carb to be very picky. I actually overdrilled twice trying to get it to run very slightly rich. Both times I overdrilled, I just had to solder the jet closed and re-drill smaller. Not hard at all.

 

[newrider3]

It's a carry-over from one of my other hobbies- building 1/25th scale model cars and trucks.

Sorry, off topic post, but you should start a thread with some model pics. I just got into it a year or so ago and have built a few.