Hey i got a mower question

[thenervemann]

KK first off do all 2 stroke engines work for gocarts?

and i have an old lawnboy mower i have used when i was like 10 and found it in the garage and cleaned it up and what do ya know it runs!! what i didnt know was that it was a 2 stroke until recently so i was wondering could i use it as a engine on a gocart like a horozontal engine?

I also have a weed eater engine would that work?

I am no pro what so ever i am making my first one hopefully. just need some help. so il be asking lots of questions.

 

[ed1380]

russ is the pro is the 2 cycle and lawnboy category

weed eater engines are really small. you could gear them down alot, but it wouldnt be the best idea.

i believe theres still a sale going on for the harbor freight blue engines

 

[thenervemann]

since i have not built anything yet i may just put the weed wacker engine on a scooter to start out.

 

[Russ2251]

Any 2 cycle engine will run in any position. 3 major obstacles must be overcome to make them 'kartable':

1.) Fuel supply/carburetion.
2.) Engine mount.
3.) PTO configuration.

I could easily dedicate whole pages to this subject.
It's my belief that most folks want something that is in the "Plug 'n' Play" category. Lawn-Boy engines are definitely not "Plug 'n' Play".
Lawn-Boy engines are not specifically kart (or even all purpose) engines and require a lot of time and patience to make them 'kartable'.
So far I have successfully converted 4 different models (2 untested), each with a little more power than the last.
I only did it for the novelty of it and a passion for the much maligned (and underrated) 2 cycle engine.
Original karts were all powered by 2 cycle engines.

 

[kibble]

I *heart* 2 cycles:biggrin5:

 

[brewster67]

i recently bought a small kart for parts and it has a 2 cycle (as you say, i know them as 2 stroke) 50cc motor on it goes really well for small person but i am 115kg and unable to sit in kart at all
any ideas about what size 4 cycle motor to use for a reliable golf course run around to carry myself and clubs?

 

[I like karts]

harbor freight blue clone 6.5 hp

 

[megaman1339]

what do you think the rpms are for a weed eater fl21 21cc engine?
need to know so i can get cluch fo rbike.

 

[Russ2251]

R/C airplane modelers get between 6000 to 7000 RPM out of 31cc engines.

 

[megaman1339]

my bike shall fly!!!:Angel_anim:
and i shall die!
BOOM!!

 

[Russ2251]

Maybe not...very low performance engines. RPM does not equal horsepower.

 

[ed1380]

you can get some RC nitro car engines.
the cen genesis makes 5hp
and some traxxas trucks rev up to 50,000 rpm

 

[I like karts]

It cant rev up to 50000, there no way


the highest I've ever seen an engine rev is 20000

 

[Russ2251]

the highest I've ever seen an engine rev is 20000

I've seen 28k.

 

[jr dragster T]

No the CEN genisis dosesnt make 5 hp no matter what people say. I have a monster gt 4.60 and its around 2 hp and it rips. And yes these .28 engines can pull 40 k rpm

 

[I like karts]

yeah those r/c plane engines rev really high

Ive never heard one over 20k though, I wonder what 30k sounds like

 

[kibble]

yeah those r/c plane engines rev really high

Ive never heard one over 20k though, I wonder what 30k sounds like

I would think that it sounds like just whining. I have an R/C truck with a .15 engine and it goes "weeeeeeeeeeeeee" when it's revved up all the way. Don't know how fast it's going. I haven't used it in years I really should fix it back up.

 

[Jerryburger]

Has anyone ever heard of the Cox ThimbleDrone .049ci? Those little buggers spin at 20k for the low performance models. I would think one of those weedwhacker 25-50cc motors could comfortably spin 10k. As far as hp goes, Russ is right. Most motors get roughly 1 ft.lb of torque per cubic inch max.... a 50cc motor is around 3cubic inches, so 3 ft lbs torque and about the same hp for a 50cc whacker-motor. If thenervemann is going to build a scooter with it, a 3hp/50cc motor would work well. I base this on my results with a B/S 3hp motor on the bike and lowrider. The bike clocked 38mph (not reving beyond 3600 rpm, and the lowrider could hit about 32mph on the flat, 38mph down a shallow hill).... all of this with my LardButt on it.
As an aside...
Has anyone ever heard of "Piston Speed per Minute?" This is the distance the piston travels in it's stroke in feet per minute. The theoretical "Gee, that's spinning on the ragged edge!" piston speed is (I think... memory fails) about 4000 ft. per minute. There are other factors that limit rpm, such as engine breathing, valve-train (if there is one), and the quality of the parts/lubrication involved, but you get the picture.
As an example: a B/S 60000 series engine (the 2hp) has a 2" stroke, which means that with a quality piston, crank, and rod/dipper assembly in place, this motor COULD spin @ 12000 rpm. Even the DuraForce is probably a 2.5" stroke, or not much more than that, so 9500 rpm is theoretically possible....
All this is based on what the Motorcycle racing teams (Honda, Yamaha,etc.) are being forced to deal with, as they try to extract every last bit of performance from a given displacement of motor.
I think the main advantage of a high-rpm capable motor is, that you can run a fairly numerically high drive ratio for good take-off, and then be able to spin the &%#$ out of it for a good top speed, all without a transmission or worry. (It doesn't require crazy hp to get a kart to go 50mph) I think Russ and The 2 Stroke guys are on to something.
Eeeesh! Sorry about blabbing- I love this stuff!

 

[kibble]

:rolleyes3: :rolleyes3: :rolleyes3: :rolleyes3: