2 or 4 stroke

[stephenm2682]

engine?

right 2 or 4 stroke & why?
moped or motorbike
lawnmower horizontal shaft
how many hp to acheive 30mph+
thank you everyone

 

[ed1380]

what application?

2stroke- better power to weight ratio. less efficient.

4stroke- less power. more efficient. lower rpm. dont have to mix gas. in some situations easier to use for our use. AKA the honda clones

 

[stephenm2682]

what application?
well what size engine would i need to get over 30mph,
would moped engine do 50cc??
how many hp or cc would i need to acheive that speed on go kart?
which engines are most suited?
thanks again

 

[r_chez_08]

depends what gearing, but a 6.5hp clone can acheve 30mph.
check out the speed calculator.

 

[stephenm2682]

okay so on average what's a moped or motorcycle engine in hp? obviously dependant on the cc

 

[ed1380]

also on 2stroke or 4 stroke.

the honda elite come with a 50cc 2stroke and a 80cc 4stroke. and the 50cc is better. its also tops out at about 35mph.

im guessing around 5-8hp for a 50cc 2stroke

 

[modelengineer]

I would say more like 2.5-3hp for a normal (non racing) 50cc engine.

 

[stephenm2682]

that's no good then, will look for atleast 6.5hp then or possibly a 125cc bike engine possibly?

 

[Kaptain Krunch]

You really cant figure out HP from cc, a 50cc engine could put out 3hp or it could put out less than 1hp, it all depends on carb settings, performance parts, fuel mix (if its a 2 stroke), and many other things. A 125cc bike engine would be great, especially if its a 2 stroke but 4 stroke is great too. My gokart has a 100cc 4 stroke engine and its powerful, it puts out around 8 or 9hp stock (according to the internet), but a 2 stroke of the same size could put out over 15hp.

 

[BradenM]

http://en.wikipedia.org/wiki/Pocketbike_racing

Stock, 2.5-4.2hp.

Now read the bit that says highly modified 50cc racing engines can put out double figure horsepower.

Horsepower is NP but Torque can be.

"Oh noez chinese crap"...

 

[modelengineer]

And torque is what you want for an off-road kart. (I can't see where it says what type of kart you're making)

 

[stephenm2682]

lol it's on another topic but i want it for on road and occassionally for off road use

 

[stephenm2682]

got chance of 3.5hp cylinder lawnmower engine, think it's horizontal shaft but can i modify it to get more power?

 

[r_chez_08]

its usually a lot cheaper and easier to start with horizontal shaft, but if you really want use a lawnmower engine. lol it is horizontal shaft stupid me!

 

[stephenm2682]

hi, it is horizontal shaft. just wondered how to get more speed out of it.

 

[r_chez_08]

oh sorry. more info

 

[Kaptain Krunch]

One great thing you can do to an engine to get more power (not more RPM's but the power will help with speed) is to either straight pipe it, or at least drill out the stock exhaust. Another easy mod is to buy a high flow air filter, from what i hear Uni or K&N are the best. You can go into removing the governor but that requires a tear down of the engine, so only do that if you feel comfortable.

 

[Kenny_McCormic]

I ran a engine with the governor intact but the linkages removed it worked fine but it was just a pos beater motor.

 

[BradenM]

Next POS I get will be ran WOT no governor until the engine dies or the flywheel does.

 

[stephenm2682]

i read somewhere that 2 stroke engines don't last as long as 4 stroke due to lubrication and you need to strip & rebuild often, anyone had any probs with there's?
ps. bought a 2 stroke engine today & gonna strip it tomorrow give it a polish etc. not sure what hp it is tho