HELP: My 49cc Scooter needs more power, it's unsafe.?

Question

My 49cc 2 stroke scooter takes at least two blocks to start moving more than 3-7 mph. Once it gets passed 10mph it accelerates normally. It is very unsafe at intersections, I usually have to go to the crosswalk and flinstone it.

Also if you know how I can make it faster please tell me. It gets up to 33mph, but I would feel safer going 40mph, most of the roads are 35 and the cars go 40. I would be safer staying up to speed with traffic, instead of pissing them off because they have to pass me. Thank You! :)

Answer 1

Hi Mugs,,,

what You are describing is a Typical thing that happens to scooters .

Your Top Speed does not seem to be Impaired,,,most 50cc scooters are Delivered being set-up to go 30~35mph  in order to abide by various Regulations.

Because it appears to Reach the Typical Top Speed expected,,,

That Rules OUT a whole bunch of possible problems.

What You are explaining is an ACCELERATION ISSUE..

Zero-to-10MPH range is just "Dead".

That is almost 100% CERTAIN a fault in the Variator-with very little doubt.

Which is NOT Unusual.

The Variator is a thing which serves as both the Clutch and the "Gearbox".

It's a sort of "Automatic Transmission",,,called a CVT.

"Constantly Variable Transmission".

They Do Not have GEARS,,,like a 3 speed,4 speed,5 speed,etc Manual Shift Transmission.

They use a BELT & Pulley System with a Centrifugal Clutch.

The way the  Ratios are Changed,,,,(same as shifting thru the gears on a Manual)----

That's done by the WIDTH of the Pulleys  being Variable,,,,it automatically Changes accotrding to Road Speed and Engine Speed.

Complicated to explain in print,,,but an ingenious system and a simple principle.

There's a Variable Width Pulley on the Engine,,,and also one  at the Rear Wheel(sorta)

Consider them FRONT and REAR Pulleys.

.........................................

1st of all,,,BELT WEAR has a Huge Influence.

But,,,a purely BELT WEAR Problem will almost always include a Reduction of Top Speed in addition to Sluggish Acceleration.

Scooters come equipped with Poor Quality Belts.

You can expect to need a New Belt,,,get a Hi Quality Belt & Nothing Less.

The Cost Difference is Small,,,and the Performance & Lifespan  Gain is MORE than worth it.

OK,,,the Slow Acceleration....

Your ENGINE will be Doing 1 of 2 different things while the Scooter is just Creeping along trying to get up to Speed.

IEngine  will be Either

A)Racing,,,running at Hi RPM "going nowhere"

or

B)Lugging,,,,Straining at LOW RPM as if it's pulling a Very Heavy Load

A) "EngineRacing">Excess RPM = SLIPPAGE in the Variator System

Could be caused by

-Bad Belt

-VariatorRoller Weights wore out

--Rear Clutch Slipping,,worn out

B)Lugging/Straining= Not ENOUGH Slippage

Could be caused by

-Front Variator "Stuck" in Too High a Ratio(somewhat rare)

-Rear Clutch DAMAGE,,,allowing Lock-Up at Too Low an engine RPM,,,,such as from Broken Springs in it(NOT unusual)

-Rear Clutch/Pulley Return Spring failing to return Pulley to "Low Gear" position(Very Common on SOME Scoots,,,Never happens on Others??)

--------------------------------------...

All that stuff is Possible for a Person to fix theirself.

But,,,it's somewhat Hard Work,,,big,tight nuts and bolts,,,etc.

And a Little bit "advanced" mechanic work.

So it's Not for just Everybody.

It takes a bit of experience,,,a certain amount of tools,etc

I wouldnt recommend a raw novice or totally inexperienced person to tackle the job.

Even though many do & are successful.

Anybody with a little Nutsy-Boltsy experience can do it.

So Repair Choices are

a)Do it Yourself

b)Get some Help to do it

c) Take it to a shop

You may not be interested in all the above Details,,and prefer to just take it to a Shop.

But Hopefully the Info helps make you a more Informed Customer.

>Dont BUY a Tune-up

>Dont BUY a Engine Overhaul

>Dont Buy a Carburettor Rebuild

>Dont let anybody sell you ANYTHING untill the Variator has been  Inspected and it's Proper Function has been Verified to Your Satisfaction.

That thing is the PRIME SUSPECT,,,a Known Cause of the type probs You are experiencing,,,and the Most Probable Cause.

.........................................

As far as ADDING SPEED.

Thats Fine,,,and Certainly Possible,,,and Not necessarily Difficult or too expensive.

But always keep in mind the Top 10 Rules about "Hopping Up " stuff for more Performance.

#1 is NEVER try to FIX a Problem by  Adding Hi Perf Modifications.

Always START by having everything in Good & Proper working order.

Rule #'s 2 thru 10,,,,see Rule # 1

I'm not being silly,,,I'm as serious about that as can be.

................................

Most of the 50cc Scooters which are Originally  Limited to that 30~35MPH range,,,,

are Actually CAPABLE of doing 45~50 mph.

So 45~50 mph Top Speed is virtually "BUILT-IN" and already available for a Small effort and expense.

They are basically "50mph Machines",,,Tuned DOWN to 30~35.

Thus,,,50mph may be pushing their Design Limits,,,but it is NOT EXCEEDING them.

That's a Very Realistic Target,,,

It's a Responsible Target in terms of SAFETY as well as Reliability and "User Friendliness"

A "Standard" DE-Restriction usually involves some work on the Variator---removing a "restricter".

You can have that done while getting the variator Checked-Out/Repaired,,,,and it should cost NOTHING extra.

All that is required is simply leaving Out a certain washer/spacer when Re-assembling the thing.

No Extra work whatsoever,,,no Replacement parts required.

Also while getting the Variator worked on,,,you can Opt for some DIFFERENT WEIGHTS.

You will probly need New ones anyway.

Heavier ones add a bit of speed,,,at expense of acceleration.

Lighter ones improve acceleration,,,at slight expense to Top speed

For City Use,,,most folks prefer Lighter ones  for peppier acceleration.

For Folks who ride Longer Runs at top speed,,and on flat,level ground---they usually prefer Heavier ones to get into "hi Gear" sooner

"Scooter Freakz" fool with the roller weights,,,trying Different ones until they find their own "Ideal".

It's an Important Area for Fine Tuning/Tweaking

That's a Hobby,Sport,,,Passion,,whatever.

Not necessary for  Basic Transportation purposes.

Next Important DE-restriction almost Always involves some sort of Exhaust Modification.

That's a MFGR's favorite place to Choke Down an engine's Power.

Removing it Varies among the different Brands of Scooters,,,but Most of them have an UNDERSIZED  INLET on the exhaust pipe,,,,where it bolts onto the engine.

Removing it is usually a Hacksaw Grind Chop Beat type of operation.

Tuff,Nasty Work ----NOT a simple Unbolt or Unscrew type job.

Most Scooter Techs have what it takes to do it For You very cheap.

I 'Bleive even I Myself would just pay somebody else to fight that fight.

Either way,,,Exhaust Destriction  makes a BIG difference in Power,Acceleration,and Top Speed.

The $20~30 it may cost to have someone do it gives MORE Performance per $$ than anything else ya can do.

It's good for at least 5mph,,,sometimes close to 10mph gain.

A Custom Tuned Hi-Perf Pipe is Nice and Way Cool,

For $150+++ it Should be.

But  in terms of MPH-per-Dollar,,,it cant even come close to simple De-restricted exhaust.

Next step,,,is to do something to allow more Air Into the engine.

That can be done by anything from spending $$$ on a Hi-Perf Air Filter replacement,,

Or simply drill/cut/punch a few small Holes in certain location on the existing air intake  assembly.

They're Tiny engines,,with Tiny carbs,,,,,Tiny Holes added yield a surprising gain in airflow>>improved performance.

Almost ALL scooters have a RPM LIMITER built into their electronic ignition  "CDI BOX".

On SOME scoots,,,Deresticing that Limiter is simply Clipping a Single Wire.

On Others,,,it's easier/better to Replace the CDI BOX with a Hi-Perf unit.

Ebay has enough of them under $20 to fill your house.

Various other sources have "Fancier" ones,,,they may be $50 or 60----and NOT NECESSARY.

Any Cheapie Generic  UnRestricted CDI is all you actually need to pep-up a Stock,Street Ridden Scooter.

The TRUTH is,,,,many Scooters will Never even REACH the  rpm level of the Limiter.

They are geared to run Top Speed at an RPM well below the REV LIMITER.

So 10 Cents spent,or 10 Seconds to Find & Clip "The Limiter Wire" on THOSE scooters is  simply a waste of time/money.

It never HURTS to have an Un-limited CDI Box,,,but it may not HELP anything at all.

That leaves a few other Tweaks.

*Carb Jetting---

usually they like 1 or 2 Jet Sizes Larger.

But on a Stock,,Derestricted Scooter that's Not absolutely necessary.

A "Race Scooter",,,something with major modifications  REQUIRES up-jetting.

A "STREET SCOOTER" may LIKE a bit more fuel,,,but does not Usually REQUIRE IT

*OIL

Far as 2 Cycle Oil that the engine uses,,,Use any name brand hi-quality SYNTHETIC Oil.

Everrything about that is GOOD,,,,No downside to it.

Not even the few extra $$ which premium oil costs,,,because it pays for itself in engine life,performance,better fuel economy,,increased spark plug life,,less maintenance to deal with carbon buildup.

They also have "Transmission Oil" in a little gearbox which drives the back wheel.

Same goes for This,,,Use a Premium,,Lightweight,Slippery Synthetic Oil.

It only needs changing every 6~12 Months,,,and only uses 4~6 Ounces.

So a Quart of Oil will last You several YEARS in most instances.

Even the most Expensive Oils dont amount to Squat-per-Year in terms of cost.

.........................................

Anyway---

Get Your Variator and Drive System Checked out

Have the Variator De-Restricted at same time,,which should be "Free"

If the Shop/Mechanic is Familair with Scooters,,,ask about  reccomendations for using Different Variator Roller Weights

Check into Derestricting the Exhaust

Consider De-restricting the Ignition CDI Box aka "Rev Limiter"

That all should result in your scooter running CORRECTLY,,,as well as at it's Desi

Answer 2

hey, your low speed jet is most likely clogged, as far as the top end, yep you can make it go faster by changing the gear ratio, sprocket is cheapest. But if your under the age (You know what i mean) you wont be allowed to drive it on the road anymore.

Answer 3

Well all 49cc scooters are speed limited from the factory. I believe to around 30mph. You can remove this speed limiter by cutting a wire. Most dealers will do this for you. As for the acceleration sounds to me as if you have something wrong with it. It shouldn't take that long to accelerate.  

Answer 4

You really need to get a different machine. Don't even think about spending a penny modifying your 49cc ....thing. Honest, no exaggeration, it is way to slow to be on the street, and is probably marginal in other ways as well.  Get a 125cc scooter or motorcycle. I know, they cost money. Well they're so economical you get a break even cost pretty quickly. At least go look. There is no change you can make that will give an even noticeable increase in the performance of your current scooter.  

Answer 5

have the dealer check it out.  if you bought one of those chinese ones, they're c**p and you're out of luck.

top speed is generally limited, you may be able to improve it a little.

a 125 or larger would help, but comes with other issues.

insurance becomes required.  

motorcycle license is now legally required as is, in many states a safety course.

registration is higher.