9hp off road buggy

[andrecht]

First time builder..
Doner parts: 1999 Yamaha Breeze
Parts to be used from quad:
4 rims & tires
Front swingarm + tie-rods
Steering pivot
Chain & sprockets
Constant torque drive & clutch

Other parts:
New 9HP Honda clone 4 stroke engine
New brake caliper, disc & master cylinder
New 3 spoke steering wheel
Fiberglass seat.

Expenses to date: ± US $490....

 

[landuse]

Nice start. I think I asked you before, but is your frame just tack welded at the moment?

It also looks like you have access to all the nice toys needed to make these karts. That is going to help a lot.

 

[andrecht]

The frame will be welded with once all the bits are complete.
The frame is evolving as the bits come in, when the final design is complete i will weld gussets into place and do the entire frame.

My mate has a machine shop, and is willing to do some work for me.....at a cost i have to say! We hunt together, and it seems that it will be a expensive season now that i have to hunt to pay my bills!!

 

[andrecht]

Motor is here!

OK, collected the motor yesterday... now for the difficult part.
Using the original Torque drive from the doner Yamaha, machined the engine block & gearbox to create a usable drive line.The idea is to connect the output shaft of the motor to the crank casing of the old torque drive......
Seem that i'm spending more time in my mate's workshop this weekend.....

What i am a bit concerned about is looking at a Jackshift, i see the clutch is on the engine output side of the torque drive,were the unit from the Yamaha is opposite way around...

Will this make any difference?
Attached is a configuration i found on this forum, thinking this might be a better option........

 

[andrecht]

Steering ....done!

Completed the steering this weekend.
Made the centre post adjustable to accommodate larger & smaller drivers!
Extended the original steering rods with high-tensile rods, still need to adjust.

 

[mysteryboy28]

with the steering set up like that you will be encountering quite a bit of bump steer. that means as one wheel goes up and over bumps, it will jar the steering in the opposite direction, making steering unpredictable, and maybe even a bit dangerous depnding on how bad the bump steer is. if your a-arms had been significantly longer (extending into the frame farther, rather than out and away from the buggy), it would have helped considerably.

try it and see. you will probably end up wanting to make new a-arms that are longer and connect closer to the steering shaft to help minimize the bump steer. this will also help reduce camber, as the short a-arms will cause a lot of camber change as the wheels goes up and down, as well as the unwanted bump steer.

the short a-arms would have worked fine in a double a-arm setup (especially with a proper length rack and pinion), because a proper double a-arm setup eliminates most unwanted camber change. however, the bump steer would remain, but would improve the closer you attach the a-arms to the steering shaft.

 

[landuse]

It looks like you are moving along nicely, but I would also have to agree about the bump steer

 

[andrecht]

OK it has been a while since my last post.
The buggy has evolved en now complete!
@misteryboy & landuse.. thanks for the advice! I ignored all your posts about the steering bump and continued with the project..... it turns out you guys were right!
Since i have changed up the steering configuration and sorted out the MAJOR steering bump that almost totaled the buggy..

Went for the first spin yesterday....it runs like a dream!
A bit slower than I hoped for but faster than expected. Opted for a 1:7.6 gear ratio, a good balance of torque & speed.. the result is loads of torque and bit low on the speed..
Running a 10 tooth on the clutch and a 47 on the secondary, then a 13 down to a final 32 on the axle. I opted for the smaller final gear on the axle to give me better ground clearance. Ill run the buggy as it is for now but will install a 32 tooth on the secondary.

I will post pictures bit later on.

 

[andrecht]

To see the build:

http://youtu.be/jANgUNy-0z8

 

[loud1]

I don't think your vice is large enough on your mill. I'm jealous, i only have a little Seig x2 mini-mill, nice setup you have.

 

[landuse]

Hey, thats great to see you finished!! It nearly looks like a Manco Dingo

 

[andrecht]

Thanks guy's

I would love to put a torque converter on it to give me a bit more power down end, but after the import duties, shipping costs & the exchange rate...it would be cheaper to fall pregnant!

Will post the weekends test runs hopefully tonight!

 

[andrecht]

@ loud1..
Unfortunately not my setup or vice....a friend of a friend who owed a friend of a friend a favor.. It is nice knowing people who now people

 

[CAPTAINCAVEMAN]

I like how you set up the shock for the swing arm. nice build

 

[andrecht]

Thanks CAPTAINCAVEMAN, the quad i stripped only had one rear shock so, used it!

 

[gear monkey]

NICE

 

[andrecht]

Test drive video

http://youtu.be/nL5AFjVpNvQ

 

[andrecht]

Went for the second test drive this weekend. Last weekend Paul managed the flip the buggy, originaly the deepdish rear rims I had facing inward, siply turned them around, widening the rear end.
Sorted out the trailer and went to the airport for a rougher test drive.

The terrain consists of long rough uphills & loose downhills.

http://www.youtube.com/watch?v=FvmyYepfepg

 

[Ozan-fox]

That bump steer looks pretty bad in the video. Don't get me wrong, its a nice kart, but if i were you i would work on a different steering setup