+30% clutch spring

[Davey-boi]

Ok guys, just bought a +30% torque spring for my vino. Installed the fatty spring and now my scoot won't start. Not only that, but when I take it off the stand and try to roll foward or backward the rear wheel won't budge. I only was able to start it when the the belt wasn't on, also I was using a stock belt. Any ideas, spring too strong???

[XPS1210]

i would guess that it's not the spring... are you 100% sure that you got the rearend back in the same?

sounds like the rear wheel is locked and you need to adjust the rear end some...

maybe you got something out of place? or the clutch is stuck "on" and or just check it all...

litterally if you can start it with the belt off... it's caused by the rear end not moving...

can you sping the wheel at all?

[King Vino]

Sounds like the rear brake is too tight. I had this issue once where I over tightened the rear brake, locked the wheel, and it would not start for some strange reason. Loosened the brake a smidge and everything went back to normal.

[Davey-boi]

But I didn't even touch the brake. :confused:

[XPS1210]

i was more so thinging that it was related to the clutch being "stuck open" against the clutch bell... causing it to be "always on" which would be like as your trying to start the motor, you are also spinning the tire at the same time... which in turn means that tiny starter motor is tring to make your scooter move not just start the scooter...

make since?

[King Vino]

That could be too. I hate trying to diagnose issues over the net or phone. That's why I try to stay clear of these kinds of threads these days. It's a lot easier actually looking at them.

[Davey-boi]

Ok, say my clutch is always on... how can I put it back to normal if it is?

[XPS1210]

Just a thought... You said something about changing your main spring... are you sure you put that all back togeather correctly? I can post a pic tomarrow afternoon if you need one to see how it should look to compair with yours....

Let me know... But the easiest way to tell is try and move your rear wheel while it's on the stand... if it's harder than normal... thats where the problem is...

[Davey-boi]

Well, took it all apart and I f***in stripped the flat clutch nut that holds the clutch and the rear pully together. Yamaha said it's gonna be friday till they can get it :eek: ! I just rushed through it and didn't reassemble everything perfectly, and stripped a damn nut! Guess I'll be riding the mojito till then....

[XPS1210]

that sucks... sorry.... did the wheel move afterwards? was that the problem?


:eek:

[King Vino]

Glad you at least have a second scooter, and a five day wait for a part is pretty quick in turn around times.

[monzav8]

Glad you at least have a second scooter, and a five day wait for a part is pretty quick in turn around times.

Yeah, Im waiting 3 weeks now for a new belt for the BV200 (Piaggio slow order system). Last time it was 2 months for a rear brake master cyl. Be glad it is only 5 days...

[Davey-boi]

Wow, two months! It would be quicker to fly to Italy, pick up the part, do some sight seeing, and still be home to catch C.S.I.!

[marylandmark]

CSI ROCKS!

On WED 10PM EST the NY edition is coming out soon.

[King Vino]

Oh, those be fighting words there Mark, I'm a Law & Order man. :p

[marylandmark]

I like that one as well but lot of repeats.

[Davey-boi]

Well, got the new nut and this time CAREFULLY threaded it on. Got it as tight as possible and............. PRESTO, my lil vinos off its vacation!!! Took the bad boy for a spin, and i must admit the lower end acceleration has improved. But I think I lost a lil top speed, which sucks.

Well, after riding the mojito for the last week and goin back to the vino has been.... lets say, a lil wierd. My once mighty and nimble vino merely feels like a toy now! I might just have to sell the lil beauty :( .

[devonrs]

so what exactly is the super tighter torque spring supposed to do?

[Davey-boi]

Basically gives you better low end torque.

[devonrs]

i don't even really know what that means... ??

[Lennox]

torque=low speed power

[monzav8]

i don't even really know what that means... ??

Torque is the rotational force that the engine puts out. More "Low-end torque" means that you have more get up and go at the low end of the speed and rpm range, which is good for a quick launch...

[XPS1210]

horse power is exactly that... power....

Torque is the "force" at which the power is converted into rotating energy...

IE: you can have an engine with 1000hp... however if there is no torque... it wouldn't be able to continue to turn at any load...

The torque is the grunt power that allows load on an engine and still continues to maintain the power output...

unfortunately the auto industry has pushed "horse power" as the power making number... when in actuallity you need a ballance of HP and Torque to have a "speed machine"

Example 2... semi truck... They have large amounts of torque but arn't "speed demons"...

Not sure if this helps but it was worth a try...

[marylandmark]

I think it is some thing like at 5250 RPM on MOST motors they should both meet- the TQ curve and the HP curve. That means your setup is set to make the most "useable" HP with enough TQ to get it there.

Sound close to being right?

[Rosso Mandello]

Torque is the actual force the engine produces, horsepower is simply a mathmatical calculation based on torque and rpm. I cannot think of the formula off the top of my head, but the higher rpm you have the torque at, the higher the horsepower.

As an hypothetical example, a deisel truck may make 600 lb ft of torque, but it peaks at 2000 rpm, so it makes about 100 hp. A modern 600cc motorbike may make 40 lb ft of torque, but it does so at 14000 rpm. Guess what? also about 100 hp. I just made these numbers up, so if you get the formula it may not match exactly, but this is basically how it works.

you cannot "measure" horsepower, you must "calculate" it. A dyno's computer program automatically calculates the horsepower based on the torque and rpm, and thats the only reason you get a horspower reading at all.

So now you may be wondering why we even worry about horsepower at all. Basically, the higher in the rpm range the power takes place at the more useable it is. That is the benifit of horsepower. The drawback is that on the street, you cannot keep your engine spinning at maximum rpm all of the time, so street vehicles are tuned for more low and mid range power, while race vehicles are often tuned to make power at as high of an rpm as possible.

sorry if I got a little long winded...

[XPS1210]

yeah... it's one of those endless debates...

As I said if I have an all HP engine... and no torque... there is no motion... You can't use HP to make a scooter or anything go without the torque as well...'


But... It's all good...

[Rosso Mandello]

Horsepower = (torque * rpm) / 5252

Without torque, you literally have nothing. HP = (0 * rpm) / 5252

Since horsepower is a mathmatical calculation based on torque output at a given rpm, there is tecnically no such thing as an all horsepower engine. However, in the real world... if you have an engine that makes its torque at a high rpm, and little at the lower rpm, you will have what is referred to as an "all horsepower engine". It still makes torque, just at a higer rpm, so the multiplication is greater. The problem with "all horsepower" is that you must slogh through the lower rpm without much torque before you get to the good high rpm torque. Using the formula, 5 lb ft of torque at 2000 rpm = a whopping 1.9 hp. That same 5 lb ft at 14000 rpm = 13.3 hp. A drastic difference. The same torque at a higher given rpm is capable of doing more work... That is what horsepower is.
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Lets say you are driving down your favorite road in your high powerd luxury sports coupe. You have a sweet torque curve that comes on strong down low and gradually tapers all the way to red line. You know, because you keep a dyno sheet in your glove box to show off. You get stuck behind this yahoo on a smokey little scooter going 55 wide open. :p When you get to the straight, you punch the gas so you can pass really close to this guy and show him a thing or two! The engine makes a bogging noise and you go nowhere... whhaah whah :confused: What gives? You're spinning at 2500 rpm, right at the torque peak on your dyno chart?

Guess what sparky, you should have shifted down.

What? Shift down... but that would raise the rpms to 3750, where I make less torque!

Yes, but that torque at the higher rpm is capable of doing MORE WORK! You are only reading half of your dyno chart!
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The key is balance. (like jered said) You need higer torque "down low" because you have to get through the lower rpms where the torque cannot perform as much work, before you get into the higer rpms where the torque is more useable.

The cool thing about the centrifical clutch on a scooter is that the engine builds up rpms before the clutch will even engage, so you miss some of that "down low" slough two stroks are famous for. If you ever race an RS250 at Daytona (tall gearing) it's VERY easy to totaly roast your clutch after only a few 13k launches :eek:

Wow, I thought I got long winded before...

[Lennox]

nicely done!:)

[Rosso Mandello]

Lets play around with the formula a little:

hp=(tq*rpm)/5252

tq=(hp*5252)/rpm

Some figures I ganked from scootnfast.tk:

Stock Zuma-4.6hp at 7800rpm.

apply the formula to learn the torque-- tq=(4.6*5252)/7800

tq=3.1 lb ft.


Polini 70cc racing-9.2hp 7900rpm

tq=(9.2*5252)/7900

tq=6.1 lb ft


Polini 70cc with "super race" pipe-10.2hp at 8500rpm

tq=(10.2*5252)/8500

tq=6.3 lb ft

As you can see, the jump in torque from the big bore kit is huge. "The super race" pipe makes more horsepower than the big bore kit alone, but almost the same torque. It simply allows the engine to breath better on the top end, where the same torque will net more horsepower.

See kids, math CAN be fun :D

[Rosso Mandello]

By the way, marylandmark, you are correct. The hp curve and the torque curve will always meet at 5252. That is the magic number that people much smarter than I am chose to be the number to devide by. It matters not weather you have balanced power or not, it will always intersect at 5252rpm because that is the number used in the formula to calculate the horsepower.

[Davey-boi]

Holy ****... your a f***in genious :eek: !!!

haha, I meant that in a good way :D !
Wow, very educational though, thanks a lot for the write up.

[marylandmark]

Ditto- Nice info bro and thanks for sharing it!

[Rosso Mandello]

No problem! Once you get me going its hard to shut me up sometimes... :D