My Dirt Devil gokart build

[Doc Sprocket]

It's a pretty sure bet that you will go faster, but how fast? Only the butt-dyno will tell.

 

[OzFab]

FYI, your wet clutch/reduction case has a ratio of 2:1, not 1:2.

Ok, This is getting confusing; some say 1:2 & others say 2:1.

 

[landuse]

Ok, This is getting confusing; some say 1:2 & others say 2:1.

I say 2:1 because for every 2 revolutions of the engine, the axle (or in this case clutch sprocket) revolves once, not the other way around. You generally give the engine revolutions first, and then the clutch/axle sprocket revolutions

Please correct me if I am wrong....

Oh, and Alex....I was wondering about the area in the pic that I circled in red. Should these not be welded?

 

[Nodroz]

I say 2:1 because for every 2 revolutions of the engine, the axle (or in this case clutch sprocket) revolves once, not the other way around. You generally give the engine revolutions first, and then the clutch/axle sprocket revolutions

Please correct me if I am wrong....

Oh, and Alex....I was wondering about the area in the pic that I circled in red. Should these not be welded?

I'll look into that, Landuse. Haven't noticed myself this yet.

Today we did a very first test! I can say the test was quite successful - nothing broke and nothing bad happened.

Problems
* Rear tires are moving. (Easy fix, I already drilled the holes in my axle to hold them in place, just was too lazy to get some bolts to attach the wheels so they don't slide off.
* Chain got really loose.. Hopefully moving the engine more backwards will get it tighter... if there's still place to move...
*Need to get decent bolts with nylon nuts to get everything properly attached...
*Clutch problem. My gokart is already moving forward without pressing the pedal. Idle speed can't go much lower... will see how I'll fix this.

EDIT; video uploaded... please don't mind the bad quality, it's dark and filmed with a phone.
http://www.youtube.com/watch?v=72ekTlW189I&feature=youtu.be
Regards,
Nodroz

 

[OzFab]

Yeah, that video's not worth much, can't see much. Shoot another in daylight if you can; I wanna see this thing properly...

 

[Nodroz]

Yeah, that video's not worth much, can't see much. Shoot another in daylight if you can; I wanna see this thing properly...

As you asked:


Oh, why I neighbours good at braking things? He was driving it once, chain fell off and got stuck between sprocket, axle and chassis. Now some chain links are bended and one even broke.... great....
http://www.youtube.com/watch?v=M8vIMg4Iuho&feature=g-crec-u

Other than that, the gokart did pretty well.

It needs a lot of fine-tuning though. Got a week free next week, so that'll be the time.

 

[OzFab]

Bad link, not found

 

[r97]

Ok, This is getting confusing; some say 1:2 & others say 2:1.

Landuse is correct, but to expand on what he said... When listing the reduction, overdrive, under drive, multiplication, etc ratio of a drive-line you list the driving mechanism as the numerator, and you list the driven mechanism as the denominator. In our application, it is just as landuse said, engine:axle.


Video link isn't working for me either.

 

[Nodroz]

Fixed link. Sorry. Youtube is all messed up now... annoying new layout..

 

[landuse]

Fixed link. Sorry. Youtube is all messed up now... annoying new layout..

Hey Alex, did you have a look at the kart where I indicated you needed some welds?

 

[Nodroz]

Hey Alex, did you have a look at the kart where I indicated you needed some welds?

Yes, I did. I welded the other side, which was not visible on the photo. Either way, I'm going to dissambly rear swingarm and front a arms to weld them all strong on all sides and then it's time to give it a little color. Just a primary coating though since I might change / re-inforce the frame later.

I'm having engine troubles right now.
* Wet clutch leaks between the two pieces. Probably just need a new seal.
* Oil sometimes leaks out from the connection between the ball bearing and the axle. Just needs a new seal too I guess.
* When I start the engine, there is an explosion coming from between the cilinderhead and the cilinder. Also a little bit of smoke. When I inspect the connection between both, there is nothing to see. The cilinder head has gone through a lot of repairs throughout the years I suppose. I was at the junkyard for a reason.

I'm going to work on my 200cc 5 speed engine. Going to the shop to get a CDI and a bobine.

Wish me luck to get it going soon!

 

[OzFab]

Haha, good luck Alex, I hope you get it going without too much trouble.

As for the other engine, it may just need a new head gasket or there may be a small gap in the head or block surface; the only way to find out is to spend a lot of time looking...

 

[Nodroz]

Haha, good luck Alex, I hope you get it going without too much trouble.

As for the other engine, it may just need a new head gasket or there may be a small gap in the head or block surface; the only way to find out is to spend a lot of time looking...

The head gasket has been recently replaced. Do you remember that topic I wrote about the Helicoils? I reckon they're getting loose under the high pressure. Not sure though, the engine runs perfectly. It's only when I cold start. Weird. Will look into this more clearly.

 

[Nodroz]

Great.... the engine is at its end of his life . Just went for my Sunday drive.... 2 minutes after I've started it I saw a long, big blue smoke curtain behind me... The whole neighbourhood was blue.

20 minutes later I started it again. Same problem. Heavy blue smoke coming out the exhaust.

The engine is officially dieing. Going to dissambly it completely and learn how these engines work.

I personally think that it is not worth to fix this engine anymore. Too many repairs already, and what will be next? This thing was on the scrapheap for a reason...

Meanwhile, I decided to sell my motorcycle engine. Enough of that chinese stuff. I want a decent brand where I can easily find parts for. And the search for a new engine begins....

Regards,
Nodroz

 

[OzFab]

Great.... the engine is at its end of his life . Just went for my Sunday drive.... 2 minutes after I've started it I saw a long, big blue smoke curtain behind me... The whole neighbourhood was blue.

20 minutes later I started it again. Same problem. Heavy blue smoke coming out the exhaust.

The engine is officially dieing. Going to dissambly it completely and learn how these engines work.

I personally think that it is not worth to fix this engine anymore. Too many repairs already, and what will be next? This thing was on the scrapheap for a reason...

Sounds like your rings are shot. Not too big a deal to fix if you can find parts

Meanwhile, I decided to sell my motorcycle engine. Enough of that chinese stuff. I want a decent brand where I can easily find parts for. And the search for a new engine begins....

Regards,
Nodroz

A small dirt bike is what to look for. Most 80s or 125s will be 2 stroke but you can get small 4 strokes

 

[Nodroz]

Ok guys, as most of you may know, I got a 150cc pitbike engine with 5 gears. I made the engine running dissambled it from the pitbike. Now it's time for conversation!

Dissambled the Honda GX270 engine and its engine mounts + fuel tank. Removed mechanical brake aswell, since I'm going to use a Hydraulic one.

I need ideas however, I don't know where to mount my engine.

I have 4 possibilities I guess. There may be more, but I can't think of them anyway. If you have any suggesitons, feel free to suggest it!

(We're looking from behind.)
*Mount engine on right side.
Advantages:
- Sprocket is nicely lined up with the axle and it has enough clearance.
Disadvantages
- Rear wheel is in the way of the kickstart.
- Clutch axle comes out in the middle of my gokart. I may need to extend it somehow...

*Mount engine on left side.
Advantages
-Clutch axle is very easy to attach to my clutch lever.
Disadvantages
- The sprocket has very few clearance with my rear swingarm. It may be a problem, it may not.
- Kickstart is in the middle of the gokart. Hard to reach and hard to kick too problably.

* Mount engine in the middle.
Advantages
- No weight distribution problems
- Clutch can be easily extended to get to my clutch lever
Disadvanages
- The 2 bars in the middle prevent the engine from sliding forward, therefor I need to extend the frame quite a bit to fit the engine.

*Mount engine on swingarm
Advantages
- If mounted correctly, kickstart will be easy to reach.
Disavantages
- Frame doesn't need any adjustments. (Doesn't need to be made longer)
- Clutch will need to be hooked up with 2 cables. Quite a bit of work and not sure if that's decent too. I can imagine it'll be quite hard to find neutral.

I forgot to mention; Wether if I mount the engine on the left or right side, I'll need to extend the frame a litle bit. If I mount in the middle, quite a bit.

What would you do?

I could also completely re-do the whole swingarm, to make it pivot higher up in the frame so I don't get a very long gokart.

Fabroman said it would be better to mount it on the swingarm.
Just wondering, will the engine be able to hand all the hops and bumps?

Sorry for epic long post, lool.
Pictures of the result so far:

 

[landuse]

I think that putting it in the middle will probably be easier in the long run. All you will need to do is extend the frame a bit. The disadvantages of the other engine locations seem to be more limiting.

 

[Nodroz]

Ok guys, I've decided what I'm going to do with the engine position. I'm going to mount it on the right side of my frame, next to my seat.

This video inspired me to do this: http://www.youtube.com/watch?v=MhCrMnyeook

I did quite a bit of work today, picture time!
*Frame is 15cm longer.
*Engine mounted.
*All cables have been disassembled, and I attached the quickly to the engine. Everything is still working.
*I took out the starter engine and tested it with my batter. It turns perfectly, then I put it back on the engine and my engine cranked over!


To do list:
*Get all cables and electronic devices mounted on the frame.
*Re-do rear swingarm.
*Disassembly hydraulic brakes form Pitbike and mount them on my gokart.
*Disassemnly shock from the pitbike and mount on the rear swingarm.
*Go for a testrit
*Reinforce frame.
*Sandblast
*Paint
*Drive!

 

[landuse]

Alex, did you sleeve your tubing when lengthening your frame, or did you just butt weld a piece on?

 

[Nodroz]

Alex, did you sleeve your tubing when lengthening your frame, or did you just butt weld a piece on?

What do you mean with sleeve?