Help me pick an engine! :D

[P@ndem1c]

okay i have been looking into buying my first go-kart motor.
i should be looking in junk yards (im going this weekend) but i want to know what i should be looking for. I am a computer programmer. I know nothing about cars. Yet.

Word on the street is that i need a lawn mower engine... but i want a little more kick than your average engine.

My only frame of reference is "Mario Kart" in which 150cc was the fastest level... i know that is not the case, but im not looking to spend over 1k on an engine if i don't have to.

$250.00-$350.00 seemed reasonable (someone please correct me if i'm wrong)
so i started surfing ebay motors. and below you will see what i came up with.

I was hoping to ask the guru's here some questions about my perusing:
Please write a reply if you have ANY answers, or advice. I'm open to any help i can get.

• Will either of these work for a gokart motor?
• Is the kick-start a retarded idea?
• are these powerful enough to let me pull a doughnut?
• Should i steer clear of these purchases at all costs?
• Are there hidden costs... like... it doesn't come with some required part?

Please let me know if these could potentially be stupid purchases. Like... if these engines are too weak to push a hotwheel, or if these are the wrong shape or design of engine for practical go-kart use, because they seem fine to me...

Here is what looked appealing to me:

NEW 11hp ENGINE REPLACE HONDA BRIGGS KOHLER 2YR WARR.
http://preview.tinyurl.com/23ow9hd
$299.00

150CC GY6 SCOOTER ATV LONG-CASE GOKART ENGINE MOTOR CVT
$168.00
http://preview.tinyurl.com/2cexabj

125cc Semi Automatic Engine W/ Reverse ATV QUAD GOKART
$230.00
http://tinyurl.com/2cjhmbh

THANKS FOR YOUR ADVICE!
-P@ndem1c

 

[T-man]

depending on how heavy your kart is going to be the 11 hp might work pritty good. The second one I have no idea. But that last one is used on alot of stuff. I found this video where the engine is like the last one, but keep in mind that the rest of the build is of a smaller design so its going to work good great because of the low weight. if you want speed I would think that the last pic would be wour best bet. other people on here my have a differant opinion. I'm just calling it how I see it.

http://www.youtube.com/watch?v=Ew8hrKRnKqM&feature=related

 

[modelengineer]

Whatever you get, make sure it's from a motorbike and 125cc as a minimum. You should be able to get a VERY nice second hand motorbike engine well within your budget.

A go kart which doesn't rev over 4,000rpm, and/or only has 1 gear (or a CVT)... just doesn't do it for me.

 

[Angus]

For reference, the largest normal racing kart motors are 125cc, and super-karts use 250cc. They're highly tuned racing 2-strokes, and make about 40hp and 90hp respectively. The advantage of racing motors is that they're very light for the power they make. Unfortunately they're so highly stressed they aren't exactly reliable, and they're incredibly expensive.

For normal/real world use, a motorbike engine of roughly double the above capacities will give you equivalent power. For example most 250cc bike engines make 35hp (more for 4 cylinder sports bikes) and 600cc sports bikes make over 100hp.

The power you choose really depends on the performance you want. 30-40hp will give you a 0-100km/h time of under 5 seconds, which is pretty quick. If you're not after that performance you can go for something less powerful.

The biggest thing with buying an engine though, is to make sure you buy EVERYTHING the engine needs to run. If you just buy an engine by itself it's a useless lump of metal. A list of things I needed that I came up with:

Airbox, air filter, fuel tank, fuel lines, throttle cable, carbies, gearbox, clutch cable, exhaust, front sprocket, chain, alternator, starter motor, wiring harness, kill switch, mounting bolts... etc.

The best way to get all that is to buy an entire bike. Or, see if your local bike wreckers will sell you a bike minus only particular things you won't need.

 

[sideways]

okay i have been looking into buying my first go-kart motor.
i should be looking in junk yards (im going this weekend) but i want to know what i should be looking for. I am a computer programmer. I know nothing about cars. Yet.

Welcome to the forum! In junk yards look for motorbikes(for engines), ride on mowers(for steering and axle), things like that.

Word on the street is that i need a lawn mower engine... but i want a little more kick than your average engine.

Lawn mower engines require significant mods to be used on a kart, if you don't have much experience with engines then don't bother with one (that includes ride on mowers). You could get one to strip down to learn about engines though.

Here is what looked appealing to me:

NEW 11hp ENGINE REPLACE HONDA BRIGGS KOHLER 2YR WARR.
http://preview.tinyurl.com/23ow9hd
$299.00

It's an industrial engine, most karts have engines like this(though normally smaller ones around 5-6hp). You will have to buy a clutch or torque converter for this engine to make it work. A clutch for one of these would probably be around $100, a torque converter would cost much more but will provide much better performance.

150CC GY6 SCOOTER ATV LONG-CASE GOKART ENGINE MOTOR CVT
$168.00
http://preview.tinyurl.com/2cexabj

These are on a few Chinese go karts, their fairly over priced for what they are though, they only have about 7hp too. I would steer away from one of these... Mounting a sprocket on that shaft looks like it could be tricky..

125cc Semi Automatic Engine W/ Reverse ATV QUAD GOKART
$230.00
http://tinyurl.com/2cjhmbh

Pretty small, I'd get something bigger than this, probably a bit on the expensive side too. Reverse is nice though, beats getting out and having to push!

As modelengineer says, a motor bike engine would be your best bet, I suggest something around 250cc, it will have plenty of power and you'll be able to find a good one in your budget. Make sure it comes with the wiring loom and carbs though.

Thanks

Hayden

 

[P@ndem1c]

Wow, thanks! a few Follow up Questions:

Wow, thanks for the advice!
and holy crap. Advice from T-man. Your videos are part of my inspiration for this project.

A few follow-ups to the reply's:

Angus & T-Man: it sounds like i have been low-balling my horsepower a bit. I should be looking in the 250cc range if i want some kick and spin out of an engine. I would much rather get too much power, than not enough. I just want to get my money's worth. Im not building this for a kid. Im building it for a 24 year old (me), and his friends.

I will need a top speed of 40mph+ for sure, and i totally agree with modelengineer that i would love the ability to "shift gears," altho i do not know the prerequisites for this functionality. I understand the basics of a transmission, but the logistics on building one seem to complex for me. can "shifting" be achieved without building out a transmission for my kart? can i snag one off a dirtbike?

And i think Angus' point is well taken:
I need more than the engine, i will need fuel lines, exhaust, gearbox... etc. That will really drive this purchase for me.
It looks like these come with "what you see here." Are the other various parts relatively easy to find?

Anyway,
I have adjusted my search for an engine to look for 250cc's (because i want to Tim Taylor this beast), and come up with two. Please tell me what you all think of these:

Honda 250cc Engine:
$249.99

Or

250CC 4 STROKE GAS SCOOTER GO KART ENGINE CN250 NEW
$349.95

 

[Angus]

If you want a top speed of 40mph, a 125 bike engine will be fine. 125cc bikes tend to top out at around 70mph or more. The acceleration probably wouldn't be great though. 250cc bikes can top out at 110ish.

Bear in mind that there will be a downgearing from the bike to the kart because of the reduced wheel size. This will result in a lower top speed and less efficient cruising, but greater acceleration. (If you wanted to you could possibly compensate for this with a strange combination of sprockets.)

I think you should really consider getting a wrecked bike or similar. None of the engines you're looking at seem to come with everything you need.

 

[sideways]

Wow, thanks for the advice!
and holy crap. Advice from T-man. Your videos are part of my inspiration for this project.

A few follow-ups to the reply's:

Angus & T-Man: it sounds like i have been low-balling my horsepower a bit. I should be looking in the 250cc range if i want some kick and spin out of an engine. I would much rather get too much power, than not enough. I just want to get my money's worth. Im not building this for a kid. Im building it for a 24 year old (me), and his friends.

I will need a top speed of 40mph+ for sure, and i totally agree with modelengineer that i would love the ability to "shift gears," altho i do not know the prerequisites for this functionality. I understand the basics of a transmission, but the logistics on building one seem to complex for me. can "shifting" be achieved without building out a transmission for my kart? can i snag one off a dirtbike?

And i think Angus' point is well taken:
I need more than the engine, i will need fuel lines, exhaust, gearbox... etc. That will really drive this purchase for me.
It looks like these come with "what you see here." Are the other various parts relatively easy to find?

Anyway,
I have adjusted my search for an engine to look for 250cc's (because i want to Tim Taylor this beast), and come up with two. Please tell me what you all think of these:

Honda 250cc Engine:
$249.99

Or

250CC 4 STROKE GAS SCOOTER GO KART ENGINE CN250 NEW
$349.95

Motorbike engines have the gearbox and clutch built into them.

That first engine looks quite good although would seem to be quite incomplete. The bike it was off would seem to have been crashed(scratches on the cases) so check for accident damage. This engine would be my pick if it was complete.

That second one is water cooled so you would need a radiator, hoses, thermo fan ect. It's also a scooter engine which means it has a CVT (continuously variable transmission) so it has an automatic clutch and you don't change gears. CVT is about as fun as walking....

Put a wanted ad for an old motorbike in your local classifieds, you will probably get one for cheaper than the engines on ebay and then you can sell off the parts you don't need and get a lot of your money back!

Thanks

Hayden

 

[fowler]

my rule of thumb is the bigger the better and it has to be motor bike there
but from what i read from your post if u want simplicity go for a horisontal sharft egine with a CVT is is not as fun but it is simpler to hook up as u have no control on gear

oh yer most people on this site seem to have this set up

 

[Kaptain Krunch]

Motorbike engines have the gearbox and clutch built into them.

That first engine looks quite good although would seem to be quite incomplete. The bike it was off would seem to have been crashed(scratches on the cases) so check for accident damage. This engine would be my pick if it was complete.

That second one is water cooled so you would need a radiator, hoses, thermo fan ect. It's also a scooter engine which means it has a CVT (continuously variable transmission) so it has an automatic clutch and you don't change gears. CVT is about as fun as walking....

Put a wanted ad for an old motorbike in your local classifieds, you will probably get one for cheaper than the engines on ebay and then you can sell off the parts you don't need and get a lot of your money back!

Thanks

Hayden

Both engines are water cooled. Not too much harder to set up (built in water pumps).

 

[bajagokart]

may i suggest a 450 out of a raptor if you can find one? then you would have reverse! and they still rev 8000 rpm or higher

 

[Kenny_McCormic]

Other than harely's, motorcycle engines usually have a 5 or 6 speed sequential constant mesh dogbox built in just like you would find in a race car.

 

[P@ndem1c]

Okay i have found some more potentials. I think i am getting warmer.
These are BEASTS!
600cc-700cc

02 SUZUKI GSX600F KATANA ENGINE MOTOR CAR KIT
This one needs welding to mount correctly. but i could handle that. It looks more complete....
$300.00
http://tinyurl.com/2ewtnez

Or what about this one:

Yamaha Virago 700 XV700 ENGINE MOTOR
$299.95
http://tinyurl.com/24qh7tf

 

[bajagokart]

get the 700 just cause you can haha frick that thing would fly!!!

 

[P@ndem1c]

i CAN, but SHOULD i?

get the 700 just cause you can haha frick that thing would fly!!!

Do you think it is in decent enough shape?
I have no problem getting this thing. im down to get this if you guys say its worth it. how hard is it to build a stick-shift or something to shift gears for something this powerful?

Are there any downsides to getting an engine this strong?

Can anyone else confirm that this engine is a decent buy for the money?

Thanks!
-Dean

 

[bajagokart]

I have no idea! Ask the seller! Why year is it? And basically if you can rig the shifter to like a lever it can't be that hard! Downside to an engine that big us weight essentially

 

[Kaptain Krunch]

both engines are missing carbs, wiring harness, and probably cdi/coil, exhaust, air filter, and probably more. Depending on the deals you get those parts could cost well over $300, or under $100. The suzuki 600 is liquid cooled, and will most likely make more power than the 700, but you will have to hook up a radiator. Your best bet is finding an old motorcycle and buying the whole thing, its worth it.

Both of those engines are overkill for anything but a small buggy, You will have to make a very strong frame, and you will be spinning the tires a lot. not that theres anything wrong with that.

Shifter linkage is the same for ever motorcycle engine. Not very hard, you basically have to make linkage to connect the foot shifter lever to a hand lever, you can use push pull cables, tie rods, or even electric/pneumatic actuators.

 

[Angus]

Yes, there are disadvantages to using engines that big. They're heavier, they're more expensive (to buy, to get parts for, to fix, etc etc), and they're probably complete overkill for a kart.

To make the most of an engine with that much power you probably need suspension and much, much bigger tyres. If you're going to have suspension you need a much stiffer frame as well. All of the above add lots of weight, so you'll need big brakes on all four wheels. In other words, a much more expensive design.

You could feasibly mount them on a small kart though, and there are videos out there of karts with even bigger engines in them. However they seem to spend most of their time spinning the wheels, and they look like they have terrible handling due to the extra weight.

You really need to make sure you get the engine PLUS ALL ANCILLARIES. All the engines you've been showing us have lots of stuff missing, which will be a complete pain in the arse to find, and will cost you lots of money.

 

[modelengineer]

I too would be steering away from anything that big. Things become very expensive very fast when you have to upgrade every part of the kart to handle the power. I'd say front brakes would be 100% necessary for something that big... Come to think of it I wouldn't be driving a 250cc kart with only rear brakes. If that one caliper fails at 100kph then you're dead. A nice 250cc engine will be perfect.

As said before the engines all have clutches and gearboxes built into the crankcase, so no issues there.
All bike engine's will require welding new mounts onto the kart.

Try to buy a complete bike. It will be MUCH cheaper and easier, and you can usually hear the engine running before you buy.

 

[sideways]

Maybe first you should build a yard kart with a 5-6hp engine, to build up your skills and so on. You'd be surprised with the performance, their dirt cheap to build too. hen when you get of it you could put a 125 on it or build a bigger one.

When I first thought about building go karts I started out wanting a little 5hp kart and then kept on thinking "no, I want it faster" "No I want it bigger" ect, I ended up buying the plans for the Edge Products Sidewinder and went looking for a CR500 engine for it. Back into reality, I didn't really have the skills to build this thing, let alone the funds so I went back and built the little kart. It made sense, you know?

Just don't get into thinking like that, you cant use a machine like that without access to vast, open spaces anyway. 0-100kph with that Katana engine in a buggy would be 5 seconds or less... On dirt... That's d4mn fast..... Unless you have lots of experience and access to some pretty d4mn nice tools as well as super deep pockets, your not going to be able to build a machine capable of handling that thing.

Don't go mad on this thing, get a 250 and build something like this. Your going to want that roll cage, you'l probably want suspension too(which this doesn't have).

Hayden