ride on convert

[flyingZ]

Hi, My son who is 11 is building a kart from an old ride on. Pulled it to pieces and was looking to attache a brush cutter engine with chain drive - Question is will it have enough torque? will it drive at all?? Gearing is 9:40

Thanks for any assistance

dad under pressure

 

[TOO FAST]

Well hard to say, what size is the engine, diameter of the tires, clutch system -
Can you post some pics?

 

[solomon]

I feel strongly you will need a larger engine as a weed whacker engine just wont cut it. You should use at least a 5hp or larger engine. I'm assuming its a 10 tooth clutch to 64 tooth axle sprocket?
Seems pretty torquey to me. What size tires does it have though? You want smaller for torque, and larger for top speed.
PICs would be great, by the way how many cc's is the motor you are using? And is it 2 or 4 stroke?

EDIT:Actually I believe That is not very torquey because you want a large sprocket in the rear and a small on the clutch. I would recommend a 70+ tooth rear sprocket and small tires in the rear

 

[flyingZ]

Looks like we have a 25 or 33cc 2 stroke engine. Engine sprocket has 9 teeth and axle has 40 teeth. Rear wheels are 13inch (33cm). Not sure about the clutch, I think the motor is one used for push bikes it seems.
my young fella who is 11 did the whole thing himself bar some small welding - not needing to go too fast (yet) but would be great for him to just have a ride... Thx for the help!!!

I've loaded some pics here http://www.diygokarts.com/vb/album.php?albumid=3

 

[Rotore]

you'll need a bigger engine anything lower then a 100cc would not pust a homemade kart at all.

 

[solomon]

rotore that is not necessarily true. I have see these karts with chainsaw engnes before.

HERE

With correct gearing it could work. But the problem is gearing, unless some one pushes you off the first 50 feet or so it wont budge =( If you make a larger rear axle sprocket preferably 60t and some smaller rear tires it would move, maybe burn out, but would be slow. If u some how mounted 2 of the engine or a 5hp or larger it could work with that gear setup

 

[brendonv]

I think the engine will propel the boy its just getting the torque to start off is the problem. U may need to push him a bit to get going as the clutch isnt very powerful on these and will slip. It probably wont go on grass all that well, only really road. Look around on ebay for a 5hp briggs or even a 2hp. I have a 2hp on mine and im 16 and it still goes 55km/h and has enough acceleration with 15" wheels. For the little kid a 2hp will be enough. Now if u want to ride it the acceleration will be bad. The only need for extra hp is for acceleration and torque. Wen my dad goes on my kart it accelerates a bit slow. A 2hp wont go on boggy sand, it goes on grass and hard dirt fine though.

 

[solomon]

the clutch will still slip, as they are not designed foe the big a load, anither idea is to make a jack shaft they work wonders on those little engines. you can get a 3.5hp on ebay for like 60 bux shipped and rebuilt

 

[flyingZ]

solomon you were right... put another clutch in it yesterday and pushed my son 300feet down the road but still no grab : ). Will work on dual sprocket set up today off a push bike to see if we can get some torque. Is this in principle what a jack shaft does?

 

[solomon]

a jack shaft i BELIEVE lower the gear reduction so it is more torqy. Io would defiantly get a much larger rear sprocket on that thing first and see if it works. Also the clutch on that little engine will most likely not stand a chance on that kart, try and weld up a go kart clutch.