Italian GP200 Top Speed

[Lamaddict]

Totally standard, good compression etc. tops out at only 58mph GPS. Nothing wrong with it, faster than Vespa's pulling away but thought it may have got into the 60's. I might put on a skimmed head as it would also keep it cooler. Standard scoots are what I like now but just thought it would have been faster.

[DigDug]

The blurb of the time stated 68 MPH so you could probably knock 10% off of that so I reckon you're not far off the mark.

Are the timing, points and jetting spot on (assuming it's not an electronic)?

[Lamaddict]

It's an electronic, running on the original 6v transducer . The only none standard thing I did was to upjet it to 120, going back to 118 would help a bit but not by 10mph more. Nice thing about the original GP/ DL is that they don't scream in 4th the way SIL ones can do with Clubman's on. I've also got an original exhaust on, it's clean and not choked up.

[davla]

I GPS'd mine yesterday, it came in at only 55mph with an AF Clubman and a high flow air filter and 126 main jet. It rides really nicely although it could do with a bit more torque and top end.

[Lamaddict]

I've had Clubmans on standard scoots and they don't seem to make any difference, they even slowed one scooter down. I guess the SIL Clubman's work because they are ported etc. I'd be interested to know the GPS speed of a SIL GP200.

[gerryjunior]

weren't the original electronics, always a little slower than the points models.

[Adam_Winstone]

"I've also got an original exhaust on, it's clean and not choked up.", please check that it doesn't have the earlier 'mushroom baffle' type standard SIII exhaust on it as this will really limit a GPs (or even SX150's) ability to rev on and get to the correct revs/speeds intended. This happened to a pal of mine when buying an Innocenti stamped exhaust for an SX150, from one of the UK's leading Lambretta experts!

Thankfully, my pal followed the modification outlined in the 60s Performance Tuning Manual and it transformed (I kid you not) the ride and speed of the standard bike.

You'll need to take the exhaust off to look into the neck of the exhaust.

Adam

[Chris in Margate]

Youre not far off. Every ride out guys say; Wow Chris you must have been doing 75mph when you came past because we were doing 70mph?
I say NO, I was doing 59 mph when I came past and then I took it up to 70mph.

[Lamaddict]

Adam, I checked the exhaust and it's the newer one, came off another GP.

Like I say, it goes well enough but the GPS doesn't lie.

I've a standard S3 Tv175, only upgrade it an electronic ignition. Clock that on the same road with a GPS at 61.5 MPH. I guess 2 stokes can be odd.

[Adam_Winstone]

GPS has certainly ruined a few people's idea about their top speeds. Before GPS we had to rely on the timing lights at Santa Pod to break our hearts (approaching 90 on a GP200 speedo normally showed about 67mph on the gantry and ticket!