Modern Vespa

Okay, perhaps I might be asking this question for other people wondering what might this magic J Costa thing be? I know it is a variator, but okay what's a variator? I assume it does something when that something changes?

So what does it exactly do?

What does it Improve?

Where does it go?

I know that everyone seems to switch to one at the 6,000 mile checkup. So inform us who are not blessed with this magic thingy.

I want one, but why?

I'll give you the quickie version...there's a ton of articles on here...go to Search, input "J Costa", check SEARCH FOR ALL TERMS, THEN SELECT "MESSAGE TITLE ONLY",and finally check "Mp3 Forum". That'll bring up a ton of info...The quick stuff:

J Costa - It's a variator.

A variator in your scooter is kinda like the transmission in your car. It holds a belt and basically determines the 'gear' for your scoot. The mp3s have a CVT, so they're always in a 'transition' of sorts for gears. The variator uses weights to keep the belt tension strong and smooth, especially at slower speeds where the engine is putting a lot of 'stop and go' strain on the belt.

The J Costa is an aftermarket variator that improves on the OEM one by having round 'special' weights that allow for smoother and stronger power at lower speeds and a general overall improvement of variator performance.

It's a bit pricey, but seems to give the best performance boost. There are other cheaper alternatives like Dr Pulley weights which replace the OEM weights instead of the whole variator.

When you do a search, Joe Bulva has a lovely tutorial on installing the JCosta on his 400 which will give you a nice pic of the unit, its weights, and where it goes.

Definition#2 - J Costas are made available for those who has the need for speed. My understanding is that it provides an extra 'horse power'. And if you want to kick it up still another notch, the Dr Pulley HiT Clutch is also available. If you upgrade these 2 performance parts, say Zooom Zooom to your paycheck too

Who sells them, and stocks em?

www.scootertrap.com

go to the model mp3 section that you have.

BTW, the JCosta(from what everyone says), does not make you go faster. It simply makes take off smoother, gives a little bit better initial accleration, but doesn't increase horsepower or top speed. As of yet, I haven't heard anyone find anything that increased top speed considerably.

I have to recommend the Dr. Pulley Sliders too. Same smoothness and performance at only $50.

Wayne B

ok what slider size? many to choice from ?

There are only two weights for the MP5 500, 15 & 16 gram. I went with the 16 gram sliders and am very happy with them. I can't believe the low speed control I have now. Also increases RPM so there is much more pull off the line and up to about 70.

Wayne B

For what its worth(don't know how big a hurry you're in), I just picked up the 15g to give them a whirl. I'll be putting them in with OAD's help here in the next week or so. Wayne, I'll make sure to post a review cause I know you said you might be interested in hearing the difference.

[BTW, the JCosta(from what everyone says), does not make you go faster. It simply makes take off smoother, gives a little bit better initial accleration, but doesn't increase horsepower or top speed. As of yet, I haven't heard anyone find anything that increased top speed considerably]
My apology. I believe you are correct Lutherhuss. It's the Dr. Pulley HiT Clutch that will give you the extra horse power, but it is recommended that you get the right tensions for the clutch & pillow springs.

HP is a measure of power the motor is putting out. Changing some thing in the transmission does not give you more HP. You have to add more fuel to get more HP.

Wayne B

[HP is a measure of power the motor is putting out. Changing some thing in the transmission does not give you more HP. You have to add more fuel to get more HP]
Let me check my resources again. I thought I read somewhere that it would provide an extra HP. Thanks for the clarification Wayne.

That maybe so but you are much faster in acceleration with a j costa, ill race any mp3 250-400-500 without the jcosta and win!

The J Costa makes the bike smoother and gives you better low speed control. In the midrange it makes it attain a higher speed quicker. It is a big improvement over the stock, in my opinion after 2,500 miles with one.

Is there a down-side to changing to JCosta and new Dr. Pulley sliders except for cost?

Fuel consumption may get worse if you start enjoying yourself!

Apart from that, nothing - safety is hugely improved at low speeds as you don't have to concentrate so much on bike control, but rather where (and how fast) you are going. Filtering becomes a breeze. The 'strangled sealion' goes back in its compound. Horrible grundly starts are a distant memory.

Only down fall for me for now, is fuel mileage has dropped big time. But that will get better as I stop using the extra acceleration I have.

Wayne B

I find that with the better slow-speed control I no longer worry too much about getting ahead as soon as possible - I wait until it'll be really good fun to get ahead, and the extra used then is far less than lots of 'little gains'. Though those can be fun in their own right.

Enjoyed this thread, good remarks and info. Can't wait to install my J Costa and more this winter.

Mike, I'm going to try to explain.


Sometimes it needs someone who understands what it feels like to not know something to explain about complicated things. So I'm going to have a go. To do it in just words without diagrams and working examples is REALLY difficult.

The problem with the internal combustion engine (a petrol or Diesel engine) is that it is a bit like a cyclist who can peddle very fast but has quite weak legs.

To start cycling from a stop (or even harder, up a hill or against a wind) is very difficult. If you have very weak legs it is quite hard to start cycling, sometimes impossible and you stall. Someone can give you a push to get you started, but it is not practical to take someone along to provide this service.

A cycle is driven by the pedals turning a large cog wheel at the front and a smaller cog wheel attached to the back wheel of the cycle, with a chain going round both.

Some clever person discovered that if you have a slightly larger cog wheel at the back of the cycle, and a relatively smaller cog wheel at the front by the pedals, it was very easy to start pedalling and move away, but even if you can pedal very quickly, the bike would not go very fast.

Somebody then found out that if you could move the chain to a smaller cog wheel at the back without stopping, (or a bigger one by the pedals), you could proceed at a satisfactory speed, once the cycle was moving.

The problem with that is that the distance round the different size cogs changes, and an elastic chain won't work very well, so it needs managing with a system of springs and wheels to keep it tight and stop it slipping off the cogs.

Mountain bikes have six different size cogs at the back, three by the pedals, and two spring loaded little wheels to keep the chain tight enough to stop it falling off. Different combinations of front and back cogs mean a rider has eighteen gears to choose from, some very similar, some quite different.

When cycling up a steep hill or starting from stop, the cyclist with weak legs selects a smaller wheel at the front by the pedals, and a larger wheel at the back. As the bike gets going, selecting a smaller cog at the back and a larger cog at the front gets the cycle moving briskly along the road. If the bike encounters an up slope, changing down a gear, a larger cog at the back or a smaller cog at the front, and the pedalling gets easier but slower.
We don't need to worry about these 18 gears just now; we need to concentrate on the three by the pedals. The pedals are the engine of the cycle, the variator replaces the three cogs. Remember when the chain is round the smaller cog the cycle is easy to start pedalling but won't go very fast, when it is round the bigger one you can ride the bike quickly.

Instead of having a chain and two cogwheels, the scooter is driven by a fairly wide belt, but instead of a large cogwheel at the front it goes around two shallow cones that are held apart by a spring so that the belt at rest is around the two flat cones that are face to face and slightly apart, in effect, round the smaller cog wheel. At first the engine turns slowly, the cones stay apart. As the engine speeds up, the weights are flung outwards by the rotation of the drive, the cones are pushed closer together, the belt is squeezed up towards the outside and forcing it, in effect, to travel a greater distance, were it a cycle, round the larger cog.
There is a really good animated film here, http://www.youtube.com/watch?v=y-QqHE0bNjw and then see it working for real here, http://www.youtube.com/watch?v=HIhLfQKKd6k&feature=related (Got to love the Labrador)

The replacement JCosta variator has different size weights (and other considerations) compared to the original equipment; these are flung outwards more easily and at different speeds to provide better acceleration away from stop, but the belt wears out faster. In manufacture, a scooter designer is looking for cost savings in build and running costs once built. The fitted variator is a compromise between these two considerations, the Costa does not work within these constraints, it is a more expensive unit to manufacture, and it may wear belts out faster, (The debate continues) and many decide that more go and higher maintenance is okay with them.

Now let the battle to tell me I've got it all wrong commence!

Hope it helps, and thanks to Jim who gave it a quick once over, any errors are still my fault!

Fonest
Fay

I didn't comment on 'the belt wears faster' - because if you use all the potential of the J Costa, it will - but in normal 'around town' use the belt might last longer, with less jerkiness on it from the clutch.

The JC weights last longer than OEM rollers in the OEM clutch in my experience - but only by 50-75%, but luckily they are only more expensive by the same ratio.

The J Costa is an expensive mod - but it does make the ride just so much more responsive I recommend it for anyone who can afford the cash 'just like that'. If you have to save for it - buy the Dr Pulley sliders instead.