Gilera runner SP 50 modifications

[lshigham]

Hi All,

As usual I have decided to start making modifications, nothing new there

To date I have:

• removed the variator restrictor
  
• installed a Yasuni exhaust
  
• installed a 2000N contrast spring and Malossi torsion control
  

Current top speed is 57-60, depending on conditions. Apparently this is the norm for the 50cc LC Piaggo's de-restricted and with a decent after market exhaust.

Next on the agenda is:

• PM Tuning Aluminium X-Tech 70cc BBK
  
• Polini Hi-Speed Variator Kit
  
• An up-jet, probably to a 70 or so
  

These parts are currently on order, so I should have them sometime next week. Planned for the future is:

• Gear up kit, undecided which one
  
• New clutch, or at least stronger springs
  

I'll keep this thread updated and will take pics during installation, just in case anybody is interested ;D

Luke

[lshigham]

The new variator and contra spring are now installed. I've taken it for a spin and it's far better up hills and acceleration is much improved, not bad for £41. It used to slow to a craw up hills, just like a car would if you tried to take a hill in 5thj gear. Now it powers up, maintaining it's usual 9000 RPM.

Next on the agenda is the BBK, I'll take pics as it will be a learning curve for me becuase I've never worked on a water cooled two stroke.

[lshigham]

I slaved into the night (literally, I've had 3 1/2 hours sleep!) to get the BBK installed. I must say, whoever designed this scoot didn't have engine access in mind. It took be over an hour just to reach the cylinder head!

I'm very impressed with the build of the kit, the ports are all chamfered and well finished.

When installing the bigger main jet I found a brass plate with 5 holes pushed inside the intake of the carb. I assume that it is some form of restrictor, so that was for the chop. I've got to get to work on this bike today, so if that plate is supposed to be there I'm a bit stuffed

[lshigham]

Well, it works! It was raining and my back end has developed habit of dissapearing off into the hedge. Haven't a clue on the speed, my speedo packed in yesterday

[90GTVert]

It sounds like a fast scoot as a 50, so I'm sure it will be fun now. Thanks for all the updates.

[lshigham]

Sept 29, 2010 7:25:20 GMT -5 90GTVert said:

It sounds like a fast scoot as a 50, so I'm sure it will be fun now. Thanks for all the updates.

OK, now the acceleration from this thing is now breathtaking. Twist the throttle and it will hit 9000RPM in a moment, shooting forward un a nearly uncontrollable manner

I've ordered some 5.3g rollers (currently 6.3g) as the kit makes most power at 10K RPM. I also ordered a gear up kit, which should increase the final drive ratio by about 20%. I owe you for the 90cc guide on 49cc scoot, it proved invaluable for calculating my ratio's.

I went back to the dealer today. They replaced the odd break handle and have ordered in a new speedo drive as mine has gone to two stroke heaven

Do you have any experience of the reliability of a single ring Nikasil plated BBK?

[90GTVert]

I had an Airsal T6 single ring plated kit for a minarelli. Great kit and seemed reliable, but make real sure you have no lean spots. The aluminum cylinders are more likely to burn the piston than cast iron. I found that out the hard way. I put a hundred or so miles on it and one day it melted the piston on me kinda out of the blue at a low throttle position. I don't think it would be as much of an issue for you being liquid cooled, but still make sure you get your tune dialed in the best you can and err toward rich.

[lshigham]

Sept 29, 2010 14:40:09 GMT -5 90GTVert said:

I had an Airsal T6 single ring plated kit for a minarelli. Great kit and seemed reliable, but make real sure you have no lean spots. The aluminum cylinders are more likely to burn the piston than cast iron. I found that out the hard way. I put a hundred or so miles on it and one day it melted the piston on me kinda out of the blue at a low throttle position. I don't think it would be as much of an issue for you being liquid cooled, but still make sure you get your tune dialed in the best you can and err toward rich.

I've never seen a piston with a hole burned clean through it before, and I hope not to on my scoot!

I've checked the plug and it's a light chocolate brown, but a bit lean for my liking. I'll up-jet it to a 72 and see how that goes.

Thanks ;D

[lshigham]

Well, it works! It was raining and my back end has developed habit of dissapearing off into the hedge. Haven't a clue on the speed, my speedo packed in yesterday

[lshigham]

Speedo has now resumed operations, highest speed I have seen is 63MPH. It should do more, with some lighter rollers and lower gear ratio. It's just a case of finding a place to try it, the speed limit is never more than 60MPH off the motorways.

[90GTVert]

Wow. Very nice!

[lshigham]

Oct 2, 2010 14:27:30 GMT -5 90GTVert said:

Wow. Very nice!

It's certainly good fun ;D

In other news, the speedo died again
Fortunately it's booked in to be replaced by the dealer on Wednesday. I would love to give Enviro a race, unfortunately it's rather difficult to cross a few thousand miles of ocean on a scoot!

[lshigham]

Gear up kit still hasn't arrived

Do you know if it is possible to fir one without taking the back wheel off? It's a secondary one.

The speedo worked yesterday for long enough to record a top flat line speed of 64mph, should be fun if I can get the gear up kit installed! The jetting is slightly off, so I'm having the dealer do it properly with a gas analyser today.

I also worked out my gear ratio's:

Stock: 11.076
New: 9.106

That's a 22% decrease.

[lshigham]

Speedo now fixed, dealer didn't have time for the jetting though. I discovered that I do indeed have to remove the rear wheel to fit the gear up kit :-(

I'm taking it to a local mechanic who tunes highly strung 2T's for a living, they were the only one's who would touch it! They have also agreed to fit the new gears.

[lshigham]

Bike is booked in for the gear up kit on Tues, I gave up and did the jetting myself. I goes like a bat out of hell up to 50MPH (9000RPM) but runs out of steam around 10,000 RPM. I suspect it's the Yasuni R which is intended to make max power at 8500, not the 10000 that the cylinder is intended for. I'm going to swap the exhaust for either a City 16-07 or a Parmakit Race One, any advice?

Luke

[lshigham]

It turns out that the Parmakit is out of stock everywhere, leaving me with the City 16 or this, which I found earlier: www.pedparts.co.uk/stage6-pro-exhaust-system---piaggio-3794-p.asp

Any yay's or nay's?

[90GTVert]

I don't know anything about the Stage 6 really. The C16 has an outstanding reputation though. I really haven't heard of poeple being unsatisfied with Yasuni pipes as long as they choose one intended for what they have and want.

[lshigham]

Oct 15, 2010 13:08:10 GMT -5 90GTVert said:

I don't know anything about the Stage 6 really. The C16 has an outstanding reputation though. I really haven't heard of poeple being unsatisfied with Yasuni pipes as long as they choose one intended for what they have and want.

Guilty as charged ;D

I didn't originally intend to be either A) Installing a BBK B) Running at 10800RPM

You are correct, as usual, the C16, although is nearly twice the price at £200 will probably be worth it.

[lshigham]

;D

[90GTVert]

A work of art. ;D

[lshigham]

Hmm, I've discovered that the LeoVince ZX is intended for 9800 RPM, that seems close enough for my liking. I know you have had a few LeoVince exhausts, any good?

[90GTVert]

I used a Leo Vince ZX on my 99cc Triton for quite a while. For that engine, it was intended for 9,500RPM, but it would rev to about 10,000RPM. The SP3 I had on a 70cc was a nice stealthy pipe, but didn't seem to encourage high revs.

[lshigham]

Oct 16, 2010 9:26:30 GMT -5 90GTVert said:

I used a Leo Vince ZX on my 99cc Triton for quite a while. For that engine, it was intended for 9,500RPM, but it would rev to about 10,000RPM. The SP3 I had on a 70cc was a nice stealthy pipe, but didn't seem to encourage high revs.

Thanks Brent. I've found this list, the Stage6 kit used is very similar to the X-Tech used on my scoot, the carb identical.

www.scootershack.co.uk/midraceexguide.html

It's clear what I should be using on my scoot, the C16 offers a 30% increase over the R and probably even more over the Z. It also tells me that the Stage6 is not worth it.

[lshigham]

Just thinking aloud here. When the gear up kit is installed the revs will likely drop down to 9000 or so, which is in the range of my current pipe. I think I'll hold fire until I have the kit installed to possibly temporarily avoid spending £200 I can ill afford.

I expect I will end up getting a C16 at a later date anyway, in my 70MPH quest. Only 5 more to go

[90GTVert]

If you aren't satisfied with the old pipe and the gear up kit, then you could get the C16 and use lighter rollers to get the RPM where it needs to be.

[lshigham]

Oct 16, 2010 20:48:20 GMT -5 90GTVert said:

If you aren't satisfied with the old pipe and the gear up kit, then you could get the C16 and use lighter rollers to get the RPM where it needs to be.

Found this earlier.



The red line is a Stage6 cylinder with the Yasuni Z. It seems to show that although it's 3 HP shy of what the C16 achieves it'll still happily rev along in excess of 10000RPM

I think that if I do go with the C16 and gear up kit the increased power will probably be enough to get the revs up, I'm only using 5.3g rollers.

[lshigham]

Ooops, did it again. For £178 I'm now the proud owner of a City 16 Aluminum, I think I need help

[lshigham]

Just admiring it makes £178 seem much more worthwhile ;D

[90GTVert]

Badass! Looking forward to your impression of it.

[lshigham]

Decided to make the airbox less restrictive. This is the back of the box.

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