Fred: PA50 shift test

I did that test you asked about on my PA50II. It shifts at 24mph on fairly flat ground. Not Iowa flat, but the average suburban street flat.

I think my drive belt is a little loose. Any idea how I go about tightening it? Should be easy, but I'm not that smart =)


... big big difference from my I... mine does it at 14... which is way too soon.

I have GOT to find out why yours (or all II's) shifts at 24.

OK... tighten the belt tension ?

Remove both plastic covers...

... there are 4 bolts that you have to deal with at the rear hub.. two on each side.. one at the top.. one at the bottom.

The bottom ones run in slots... once you loosen them.. you can swing the hub back farther in the slots.. tighter belt.

Crack the top ones loose... they stay where they are.

Now get your face down there at the bottom bolts... and observe where the bols are in the slots.. (there are marks).

Now crack the bottom bolts loose loose.. pull the wheel back a little bit (you can look at the marks to see how much you moved it).. tighten all 4 bolts back up.

Re: Wow..

> I have GOT to find out why yours (or all II's) shifts at 24.

I actually feel the shift too. Thanks for the help as far as belt tension goes. I didn't notice the upper bolts, I'll have to mess with that today.

So how's the low end on your PA50. Starting from a dead stop without pushing?

Any luck getting that guy from ebay to send your parts? I ordered an owners manual from someone and have been waiting a few weeks too.


Re: Wow..

Travis Bright /

my suzuki fz50 shifts at 13-14 too

Loosen Chain Tensioner

ItsLookingUp /

You may need to loosen the chain tensioner with a 10 mm socket on the right side of the bike. My manual states that the belt should be deep enough into the rear pulley to see 2mm of pulley. It suggests rolling the rear pulley back and forth until the belt drops in exposing 2 mm of pulley.


Low end on mine is pretty bad (slow).. I raced a Tomos Targa yesterday and he pulls me up to 24 or so by 20-30 feet... then my good 'top-end' power kicks in and I go rolling past him.

When I raced Ree's 'new' Targa... He pulled me too up to about 10mph... then it seemed like we were about even... till my top end... then I pulled him.

When you get a chance.. time your 0 to 25.

We need casey to time his... his II is fast (with a Proma pipe)

My parts off ebay are supposed to get here Friday .. I am borderline wanting to leave the guy bad feedback.. He is slow.

The first thing I am going to do is swap that ramp plate.

On the chain and belt tension... I forget you guys still have your starting system on... I removed my pedals and pedal crank and chain years ago... I just push start it... 3 or 4 quick steps and release the de-comp lever... I'm off.

Re: PA's

> When you get a chance.. time your 0 to 25.

> We need casey to time his... his II is fast (with a Proma pipe)

Right now my variator is all apart. One of my notches is about 1mm too deep so the roller gets stuck at high speeds. So I'm having my bro-in-law who's a welder fix it for me. He said it's a pretty easy fix, but I forget the term he used for what he's going to do. I never had any problems with it until I put the Proma on and started hitting really high speeds. Usually it gets stuck after flying down some steep hills.

I did receive my owners manual today. Anyone want me to post specs or anything like that?

Re: PA's

Matt Wilson /

What shift are you guys talking about?

I thought that a variator was designed to shift smoothly throughout the entire range, as the belt moves up the pulley.


Re: PA's

Did you read my other post about this same subject when you asked yesterday ?

I ain't writing it twice.

Re: PA's

Matt Wilson /


I thought that I forgot to write it the first time since I couldn't find the thread.

And about the point where you bike "shifts" I think that if you use lighter roller weights the engine will rev up faster and you will shift earlier. This is a common mod done to modern scooters, however it may be hard to find aftermarket rollers for the PA's. Malossi makes rollers for modern scooters in many wieghts from 2g to around 13g a piece. Most scooters use around 7g

The downside is that your top speed may be comprimised by a mph or two because the rollers won't move up as high on the vario.


lighter means later

lighter weights means it would 'shift' later... (takes more RPM for the weights to overcome spring tension)

I have considered a few ways of doing it ... but shimming the coil spring that counteracts the centrifugal force... might be the easiest way.

Making them heavier is easy... lighter is not as easy.

But... besides that... basically you are right when it comes to more modern variators... they are SUPPOSED to be more variable than these PA's are.

Re: lighter means later

I have a weird question for you - have you ever tried to use a variator with both light and heavy weights in it? the heavy ones would move out first, then the lighter ones would go out at a higher RPM.....

It may not work, because that would mean that your variator would open up lopsided, or all the weights would travel down the ramps at the same time. Unless you had a different profile on each ramp.....

crap I lost the train of thought. Plus, it would probably eat up a lot of parts in testing.

Re: lighter means later

david f martin /

The PA variator has only 3 rollers, I believe, so mixing weights would throw it off balance. My Elite's variator has 6, so it might be possible to mix weights if they were alternated (light - heavy - light - heavy, etc.).


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