question on engines...

[redneckengineering]

i was looking at amazon and saw this http://https://www.amazon.com/4-stroke-Semi-Auto-Transmission-upgrading-50cc-110cc/dp/B014R2GBOK/ref=mp_s_a_1_3?ie=UTF8&qid=1541702988&sr=8-3&pi=AC_SX236_SY340_QL65&keywords=125cc+engine&dpPl=1&dpID=51V-6CW9DfL&ref=plSrch and i was wondering if the karting community thought it any more useful than a predator 212 with a torque converter. the way i see it, pred. 212 would cost $200 with a torque converter and this atv engine costs about $250 including necessary parts. predator has 6.5 hp and this atv engine claims 7.64 hp. predator comes stock with 3600 rpm, the other one claims 7000-8000. torque converter would make predator an auto tranny (technically), and the other comes semi-manual ( obviously superior). the atv engine also comes with a reverse gear. the predator would be more easily modified, though. am I missing something? personally i like the sound of the atv engine, but is there some major deterrent here I am missing?

 

[Kartorbust]

All a Predator 212 and the like are just standard industrial engines, built to power equipment. Sure they have used them for years in gators, golf carts, etc, but mostly they are used in stationary or slow moving machines. That other engine is more or less purpose built for karts and such. Technically that is the better engine for karts.

 

[Clifton]

You can get the cost of the predator + TAV down to probably $160 if you use a coupon on the predator & order the TAV off ebay. I've also heard that just removing the governor that the hemi predator makes about 8 hp. There's a lot more information on the predator/clone engines too, you have an entire kart racing community that use the clone and predator engines and ARC making billet parts etc for them. You also can't just bolt that engine straight up to most of your standard yard karts.

Definitely an interesting engine though at that price.

 

[Kartorbust]

$100 for the Flywheel
$85 for connecting rod
$20 for the springs
$99-$120 for the engine ($99 with coupon or membership).

All for some slightly similar results from that engine.

It all comes down to what you want to do.

 

[ezcome-ezgo]

Drawback on this engine is it doesn't come with Carburetor, Battery, CDI, Voltage Regulator, Ignition Coil etc. So there's plenty additional dollars to invest before you've got something you can use.

 

[KartFab]

am I missing something?

Predator 212 Pros:
Low RPM torque+torque multiplication using the torque converter= amazing acceleration.
Predator 212 can be upgraded to rev to 9k rpm 10-25ish hp (stage 1=10hp, stage2=10-15hp, stage 3=15hp+, stage 4=20hp+)

Predator Cons:
costs lots of money to upgrade to serious hp
torque converter wont handle the hp increase if you upgrade, you need to switch to a clutch shoe or disc clutch

dirt bike engine pros
inexpensive
reliable
gears make for really fun riding and top speed
one time cost for engine, 'already upgraded'

dirt bike engine cons
internal gearing of engine will likely require different gearing of rear axle sprocket for your go kart or mini bike
cannot really upgrade for insane hp gains like you can with predator engines. the engines are already more efficient/optimized to rev high and have better carbs. they area 'preupgraded' if you will haha.

Which to buy for budget friendly?
wrecked motorcycle/dirtbike engine with all wiring carb etc. Then you will have too much engine, but it will be fun to ride.