Speedfight 2: Not Running Right With New Parts??

Leave the hard springs in and use the 7 gram rollers, to see what difference that makes. If it still crawls along, put the original springs back in and see how 7 gram rollers performs with them. It's trial and error but you should only change one thing at a time and note what the change did, otherwise you are just groping around in the dark.

 

yes gonna do that mate just double checked the plug a min ago and its a nice coffiee colour maybe a tad rich but its good, and ill make a start tomorrow and report what happens!

 

Well put the 7g rollers in with the soft clutch springs and it's getting to 45 now but it's slow slow at acceration, also if I stop on a hill it struggles to set off? Should I put the medium clutch springs in and see what happens?

 

Yes, that's the next step. When was the drive belt last replaced, as the belt might be worn to the point when it starts to slip? Slow acceleration and take-off like you describe could be the belt slipping.

 

no idea it looks ok to me but ill put a pic on soon so you can have a look at it!

 

What about the OP.....lol

 

@ Inked

Did the rollers have any flat spots on them when you took the variator off?

 

had flat spots on the stock 8g ones

 

Thanks for noticing me mate ...lol

The stock 9g rollers were more of a hexagon shape..lol

But these have all been changed now, really the only thing I'm trying to figure out is why I can't fit the correct size belt without having problems.

 

Are you sure that you have the stock variator? I'm not sure as to why the new belt is giving you problems. My TKR2 has a Polini sports variator and as far as I can tell, it uses the stock belt, although I ordered an Athena replacement for it as part of my engine rebuild.

 

Yes mate, it's definitely the stock variator.


I can't understand why I'm having these problems either.

If you look at the pictures I posted up on the first page of this thread you'll see that this new belt is a bit wider that the old one, but it shouldn't be a problem as the new one is the stock size.

 

Any other ideas ?

 

I don't at the moment. The belt size I quoted should be the right one. it might be worth phoning one of the online scooter shops for their advice on this.

 

Sorry for the late reply.
All else being equal, when you fit a better exhaust you change the power delivery of the engine. You get more power, but at higher revs. If you do not modify the transmission (lighter rollers) then your engine will never get in the rev range it needs to deliver that extra power.

In fact, if you do something to the engine and it struggles to get higher in the revs and your speed is actually slower as a result , this is a sure sign that
a) you have increased power
b) you need to subsequently modify the transmission to make use of it. Lighter rollers !
Beware - you may need to upjet. Keep a check on the plug colour.

On belts: Are they weird or what. If you use a thicker belt you need to space out the variator (like in the video) so that you get some slip to get going.

On general advice: Start light with the rollers and progressively increase until you feel the power getting laid down. Start rich with the jets too. Reduce roller weight. And pay attention to what is doing what. It's no good fiddling with clutch springs if the scoot is taking off ok but bogs going uphill at 30. Similarly, if the scoot is OK at 15 mph and upwards but crap at the start; it's no good looking at rollers. You need to look at clutch stiffness.

If you put a thicker belt on the scoot - it stands to reason that the variator will start off with the belt higher - so that will reduce the mechanical advantage of the system at the start. Add some washers to the slider (like the video).

Good luck.

 

Ok thank you gonna go for 5.5 rollers

 

Thanks for the reply (and a good one at that )

Ill try some washers (as soon as I can find somewhere in the UK that sells the correct size) but it seems like your under the impression that I'm trying to fit a wider than stock belt when in fact I'm actually tribe to fit a standard size belt.

I don't think these scooters come fitted with washers so why do I need to fit one now?

Also I'm starting to think that my low top end power could be caused by the narrow belt that's in there as I can feel the engine pulling until I get to just under 40mph then the power sort of tapers out but the engine still rev up a bit more.

What I'm thinking is that maybe the belt isn't wide enough to reach to top of the variator?

 

Thats an easy thing to check. But you have to be careful. Take the belt cover off, remove the starter bendix because it will probably either fall out or snag in the next process, put the belt cover back on, kick start the bike, remove the belt cover, rev the bike and see if the belt is moving up to the top of the front pulley and right to the bottom of the rear pulley.

 

I'll give it a go

Someone also said that you can rev it up while holding the brake to do the same thing.


But this still wouldn't explain why I'm unable to run the stock size belt?

 

you could do it that way, but you want it to imitate what it is supposed to be doing on the road, so the wheel has to be free of resistance, i.e the rear brake.

 

Not all variators/sliders are the same. My Doplller SB2R came with two of different widths and I have aquired more since because I use belts for a 125 scoot made by Bando that are the same dimensions as the Malossi Overrange belts, slightly wider, (but half the price!) If the one you have has a wider slider then going from a re-inforced belt back to a standard belt will lose you top speed - and your idea of the variator not riding up all the way is right. Steeve P's test should tell you.
Or you could pinch the belt with the corrector compressed like I did in the video. If it has absolutely no contact with the variator/pulley when you pull the belt back - it's a fair bet the slider is too wide for the belt (or the belt is too narrow for the slider - depending on which way you look at it).