From scratch build

[SkidooTNT]

I'm was looking for a summer project and this seems like a fun one.

I'm thinking of building an off-road go kart or small dune buggy probably a 2 seater. I have a 340, 2 stroke, air cooled engine I'd like to use. My welding is getting pretty good and I'd like to build every thing my self.

I'll post some frame designs I've sketched later. Plan so far is a double wish bone front suspension and a solid drive axel hinged at the back. The motor would go above the drive axel mounted to a solid portion of the frame that also connects to the shocks supporting the drive axel. Thinking I would use 1.5 inch square tubing as I don't have a pipe bender.

Any input would be great.

 

[Poboy kartman]

to the forum....sounds like a plan!!!

 

[SkidooTNT]

Here's one of my first sketches. The lower one won't load.

Plan is to weld this frame over a similar frame with enough slope to have the motor well above the wheels at the back.

 

[bread]

ive actually heard pretty good things about this one if you know how to use it, im going to pick one up soon

http://www.harborfreight.com/12-ton-hydraulic-pipe-bender-32888.html

 

[SkidooTNT]

Not exactly sure what my budget is yet and I already have to get a band saw. If I do get a pipe bender then I also have to find someway of cutting the joints for welding. That's the part I think is out of the price range.

 

[bread]

I understand what ya mean, if your gonna do the round tube, you gotta get the bender, notcher, press, etc

square tube is far easier to work with (angles, etc)

if the bandsaw is for cutting square tubing, just get a chop saw

i have this one, it's great

http://www.amazon.com/DEWALT-D28710-14-Inch-Abrasive-Chop/dp/B00551DJBQ/ref=sr_1_1?ie=UTF8&qid=1463332354&sr=8-1&keywords=dewalt+abrasive+saw

 

[SkidooTNT]

I've got your point with the chop saw being much cheaper, but a band saw is much more ergonomic to use and makes very clean cut compared to a chop saw.

 

[Poboy kartman]

I've got your point with the chop saw being much cheaper, but a band saw is much more ergonomic to use and makes very clean cut compared to a chop saw.

That depends on the chopsaw. Personally, I just use a mitersaw with skillsaw sized metal blades and just shim the tubing up with wooden blocks. I get very little deflection with the small blades and a very clean square cut.

I used to be able to set the angles but have used it so long the table is locked on 90° because the shavings and abrasive powder have jammed it up. All I'd have to do is take it apart and clean it to be able to cut miters.

Something to think about....and both the mitersaws and blades are cheap.

 

[SkidooTNT]

All something to think about.

What's your opinion on using the 340 engine? It's the motor I have so I'll be using it but I'm just wondering what's out there for set ups.

 

[chancer]

ive actually heard pretty good things about this one if you know how to use it, im going to pick one up soon

http://www.harborfreight.com/12-ton-hydraulic-pipe-bender-32888.html

I have one, It is OK, (at best) but it is a PIPE bender, NOT a tubing bender.
Trying to bend 90°s is not that easy it wants to kink the tube. Even using heavy wall gas pipe it will kink 50% of the time.
It will get the job done but it takes practice.
Do the U-Tube research, to make sure it is worth it to you.
Also I got mine on Craigs list 40 bucks. It was 1 of 3 that week.
Just not really worth the Money for a new tool that is not that good.

I mean it is a fine tool, but using it for a Tube bender to fab Kart frames is just not what it is designed for.

 

[bread]

I have one, It is OK, (at best) but it is a PIPE bender, NOT a tubing bender.
Trying to bend 90°s is not that easy it wants to kink the tube. Even using heavy wall gas pipe it will kink 50% of the time.
It will get the job done but it takes practice.
Do the U-Tube research, to make sure it is worth it to you.
Also I got mine on Craigs list 40 bucks. It was 1 of 3 that week.
Just not really worth the Money for a new tool that is not that good.

I mean it is a fine tool, but using it for a Tube bender to fab Kart frames is just not what it is designed for.

yea I was considering buying one myself to investigate

I also have heard that filling tube with sand and welding caps to ends prior to bending reduces kinking... but what a hassle

 

[SkidooTNT]

Ya that is way to much work for a bend. Think I'll be sticking to cutting angles in square tubeing.

 

[chancer]

yea I was considering buying one myself to investigate

I also have heard that filling tube with sand and welding caps to ends prior to bending reduces kinking... but what a hassle

I used Gas pipe so I could thread caps on but the sand did not help that much.
Totally not worth the hassle.

 

[bread]

I used Gas pipe so I could thread caps on but the sand did not help that much.
Totally not worth the hassle.

dang, I was counting on one of these benders, what about the fact that pipe has a welded seam? tubing (DOM for exsmple) is created differently

 

[chancer]

That is one of the tricks to using this bender.
You have to put the seam on the side of the bend, not the inside or outside. So the weld does not try to stretch or shrink.

 

[MonsterBike]

I assume your 340 is a ski-doo 340. I had one on a sled and it was a lot of fun. However, if it has a Tillotson carb, those can have some issues. I am not sure at all but I've heard that TNT 340s were dual carb? I don't know. We went through putting 2 seal kits on the Tilly and finally got it running fantastic. But yeah, the 340s are great engines.

 

[SkidooTNT]

Yes it is a skidoo 340 with the duel carbs. Not sure on the carb make though.

 

[MonsterBike]

Snowmobile engines were probably originally intended to be ripped out and put in karts anyways. I love big cc 2 strokes, they smell and sound great.

 

[Desertduler]

Take it from someone that has two karts and a minibike with snowmobile engines on them. You will not regret having the power that they put out. Fun stuff!

 

[SkidooTNT]

Is there anything I'd have to do to the engine besides adjusting the carbs and oil pump for warm weather? Anything to help with cooling the engine?