My scooter seems to have slowed down

[a.j]

O.K Further to my last visit to this page I have liased with more knowledgable folk than me & I'm led to believe that the Kegra pipe combined with the SX200 gearbox is making the engine overgeared.

Would it be feasible to try a Gp 200 box, 47/18 sprockets & 82 link chain?

Or would an alternative to this be an Li150 gearbox which I have at home & if so would I still have to mess about with the sprockets & chain?

[rosscla]

I think you could still get the same final ratio with the Li box but the GP with 18/47 will be easier on your clutch

[a.j]

Cheers. I am going to have a look & see what's inside later tonight & report back here. I could stick a clubman back on I suppose & be done with all this nonsense, but when money is laid out I want to see some return.

[a.j]

Right...I put in an Li150 gearbox, crown wheel & front sprocket 15/46 & it made no difference. I went out with a lad who has a GT186 kit in his, we swapped bikes yesterday for ten minutes & he was shaking his head in frustration at the lack of speed & pull my scooter had. So this morning I was up early, got in the shed & took the kegra off, replacing it with the old 42mm AF clubman & it flies! I just do not think my set up liked the Kegra. There is absolutely nothing wrong with it because on the dyno with the kegra fitted it touched 80 mph, I didn't see what BHP it was putting out but all the same you would expect a dynoe'd speed like that to return something more than 50 mph balls out with the strong wind behind you eh..

[Adam_Winstone]

With the Kegra on it should have gone like a rocket, provided you were prepared to keep it at the higher revs, hence the 80 on the dyno. However, keeping it in the revs can be a pain as it makes for a ride that is either revving hard and going fast or not revving and going slow... meaning that anything less than flat out will see you working the motor up and down through the gears to chase the power. Personally, I find this type of power delivery very tiresome regardless of what BHP it might peak at on a dyno

So many people are fixated on BHP figures that they've forgotten about how a bike actually rides on the road. The GT kit that you mention is well known for being at the lower end of the BHP kits, but has a great wide powerband that makes it a pleasure to ride from low revs, right through the rev range so your mate must have really felt the difference in power delivery. That said, your Kegra pipe example shows that going 'too peaky' can be result of pipe, just as much as it is about tuning of kit. Indeed, take a standard TS1 kit and try 10 different pipes and it can feel like you’re trying 10 completely different motors, simply because of the different RPM/power delivery. In the same way, your swapping of pipes is making your top end feel completely different.

Unfortunately, so many people only see BHP figures when they look at pipe review graphs, whereas they should often be more concerned about how wide the powerband is and where it is along the RPM axis.

Hopefully you are getting somewhere with your motor now. If you feel that you still want more power from your motor then you can still look at expansions... just make sure you're not focussing too much on BHP.

Adam

[nuttyboy]

don't all scoots go faster on dynos than real road conditions .mine runs out at 70 on dyno will never touch that on road .

Sent from my KFTT using Tapatalk 2

[mick1]

Very little wind resistance on a Dyno.................

[Adam_Winstone]

Don't get me wrong, a dyno is perhaps the dream tool to have... but it is only as good as the person operating it, and in turn, if you take a sow's ear to them, don't expect a silk purse when they are finished. As such, dynos are great but they really are just another tool!

Adam

[Avantone]

Do you have a copy of the Dyno sheet you can post?

[a.j]

No mate sorry. It was just a quick check & I have loads of dyno sheets at home anyway. lol.