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Re: Italian GP200 Top Speed

Posted: Wed Aug 24, 2016 10:30 pm
by Doom Patrol
Lamaddict wrote: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.
Yes, but don't forget the TV would have the taller SX gearbox, so it ought to be faster, if not quicker.

Re: Italian GP200 Top Speed

Posted: Thu Aug 25, 2016 2:30 pm
by shocky
Lamaddict wrote:It's an electronic, running on the original 6v transducer :D . 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.
Ive just removed an Italian box and fitted the original indian back and they both rev the same in top acording to my sip speedo Ihave a pm25 pipe fitted

Re: Italian GP200 Top Speed

Posted: Thu Aug 25, 2016 2:47 pm
by shocky
Lamaddict wrote: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.
My standard one showed 62mph on sat nav and the sip speedo with a massive 2.2 mm squish
I set about rebuilding the engine even though it was reliable I just had doubts about some of the indian parts
the normal hi load bearings throughout viton seals everthing shimmed and checked inc chain height welded inner and outer cluch ,deep 5 plate rear sprocket topend was matched to manifolds and casing ports were satin polished by proporting who also did the the 110 conrod on the old crank squish set to 1.2mm and 18deg timing
it runs a standard 22mm jetex with a modified atomiser to run richer mid rand and a pm 25 pipe
it now tops out at 67 mph gps with a little more to go and will sit at 60 mph for extended periods altho hitting a hill makes the cht gauge rise :/ whilst not totally standard its not far off what a well built standard engine should do I could add a 19t front sprocket as it pulls top from 30mph with no hesitation
ive tried various exhaust s inc a jl4 but it would pull top under 40mph and when it was windy lacked power and spoilt the ridability it also uses a 3 ring meteor piston and 5500 miles later is still going strong

Re: Italian GP200 Top Speed

Posted: Thu Aug 25, 2016 3:40 pm
by lloydy
I've got 52.7mph out of my recently rebuilt DL200 but only 800 miles into running it in. She has 12V electronic ignition with a Scootopia exhaust & standard SH2/22. Certainly doesn't seem to have another 20mph in there to meet the advertised top speed, but I'll wait & see.

However it's not currently running at all due to MOT failure for excessive rear wheel play (endplate keeps coming loose) Rightly so as that's dangerous at any speed!


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Re: Italian GP200 Top Speed

Posted: Thu Aug 25, 2016 5:09 pm
by sean brady scooters
back in the 80,s,and before sat navs were invented obviously ...the best and most simple way of checking scooter speeds was to just follow and check with a car speedo,not as accurate as modern means but a damn sight better than scooter speedo readings !...they were always way out ,and always on the high side never under strangely lol

Re: Italian GP200 Top Speed

Posted: Thu Aug 25, 2016 5:42 pm
by bristolmod
you need to remember that when these bikes were built, there was NO advertising standards. Innocenti could say anything they liked and get away with it!!

I'll bet Innocenti's figures were a touch higher than the Vespa figures for their comparative scooter- when Vespa brought a new one out, its top speed would be slightly higher than the Innocenti one- and so on......

Chris

Re: Italian GP200 Top Speed

Posted: Thu Aug 25, 2016 11:27 pm
by Lamaddict
Ref Scootering Second Edition. Probably taken from original literature

GP 200 Power Output 11.74hp @6.200rpm Max Speed 68 MPH. Seems out.
GP 200 (SIL) Power Output 11.9hp @6.200rpm Max Speed 74 MPH. Seems way out. Although we know the barrels were 'stage 4' plus the SIL Clubman and bigger main jet.

TV175 Power Output 8.75hp @5.300rpm Max Speed 64 MPH. Not far off.

I guess we could also make allowances for weight and modern fuel. I'm 14,7 Stones.

Re: Italian GP200 Top Speed

Posted: Fri Aug 26, 2016 1:36 am
by Lambretta Sash
Ran a mates std sx200 up with 22mm dellorto, airbox and std pipe 8.41 Hp and 51 mph.
Those hp figures are at flywheel and not rear wheel.
Ny Tv 175 motor pulls the sx200 no problem its on 20mm dellorto and af clubman will un up when i get a chance.

Best I've seen from a lammy in std format is a Tv200 with 22mm carb, text book mods and outrigger pipe topping 65 mph

Re: Italian GP200 Top Speed

Posted: Fri Aug 26, 2016 7:13 am
by Morgan
Lamaddict wrote:Ref Scootering Second Edition. Probably taken from original literature

GP 200 Power Output 11.74hp @6.200rpm Max Speed 68 MPH. Seems out.
GP 200 (SIL) Power Output 11.9hp @6.200rpm Max Speed 74 MPH. Seems way out. Although we know the barrels were 'stage 4' plus the SIL Clubman and bigger main jet.

TV175 Power Output 8.75hp @5.300rpm Max Speed 64 MPH. Not far off.

I guess we could also make allowances for weight and modern fuel. I'm 14,7 Stones.

I thought the Italian and Indian GP final drives were the same (5.2:1 or thereabouts) seems odd they reach different speeds with the same drive ratios :?

Re: Italian GP200 Top Speed

Posted: Fri Aug 26, 2016 2:42 pm
by Muppet
really them has different barrels and exhausts as std