Scomadi speed issue

[red]

Just been out on the Scomadi tonight as it'll only sit at about 62 mph flat out on the flat,loses power when climbing hills.

The belt and rollers haven't been changed for about 11000 miles could this be the issue?



Problem is I'm supposed to be going to our club rally on the Isle of Bute on Friday morning and can't really do it sat at 60 all day

[coaster]

I had a similar problem on my GTS 250, flat out (9,000 rpm) and bouncing of the rev limiter at 68 mph. The rollers were shot so I fitted a set of Polinni 14 oz rollers and it now is happy at 78 mph (gps) on the flat and will hit over 80 with the wind behind me. The job takes about an hour with most of the time spent trying to get the air filter bolts back in On yours it will be a 30 minute job but your will need 2 special holders for the clutch and the fan on the actuator. That belt will be shagged by now too.

[Andy Pickering]

Well im no expert on these matters old bean but id say either your laggy band is stretched or the mouse has shin splints

As always here to help stephano btw ride safe at the weekend I know your riding a long way

[red]

I had a similar problem on my GTS 250, flat out (9,000 rpm) and bouncing of the rev limiter at 68 mph. The rollers were shot so I fitted a set of Polinni 14 oz rollers and it now is happy at 78 mph (gps) on the flat and will hit over 80 with the wind behind me. The job takes about an hour with most of the time spent trying to get the air filter bolts back in On yours it will be a 30 minute job but your will need 2 special holders for the clutch and the fan on the actuator. That belt will be shagged by now too.

I haven't got replacement belt,rollers,or tools though and supposed to be going to Bute early doors Friday.

Looks as though my rally money will be going on parts

[coaster]

Genuine Vespa rollers should be about £10, the Polini ones I used came from SIP and were only £6.99. If the belt isn't frayed you could get away with it for a bit but then if it is frayed it might be too late get another one. If you were nearer I'd gladly lend you my special tools, I got them from Rainham Boy on the GTS forum, he's quite fast but you'll be pushing it for Friday. Maybe there's a dealer near you that would rent them out ot perhaps try asking on the GTS forum if anyone is close by?

There are a couple of clips on Utube showing how to remove the variator and belt, have a look, one has a universal flywheel holder being used.

[coaster]

Just had another thought which will cost you a pint someday, PM me your address and I'll post my tools up to you in the morning so they will be with you by Friday, Phone Cheeky Thomas (off the GTS forum) he's a dealer and is the cheapest supplier of vespa bits 01502 584169. Phone him first thing in the morning and they should get the order out for a Friday delivery.

Colin

[TED CRUD]

If your belt is shagged ,DO NOT ride it .Worn belts snap an i have seen them jam the back end up at speed also snap cranks on two stroke autos !!!!!!

[Darrell Taylor]

Hi Red
the variator and clutch nut can be buzzed off with a battery gun or air gun ,loss of top speed on auto,s is generally down to a change in belt dimension as it wears down on the belts side friction faces the belt becomes narrower which results in a lower first gear and lower top gear as the belt sits down lower in the gear pulleys,a transmission service comprising of belt/rollers and most importantly but often forgotten rear torque spring is gonna get the transmission back to its best,the torque spring behaves like roller weights and a worn spring (reduced tension) will be the same as fitting heavy rollers so youll find it setting off at lower rpm and holding lower revs under the motors natural peak power operating rpm
in reply to your other post on rollers all your trying to achieve is the correct weight that holds the engine at peak power rpm so if your motor makes 20 bhp at 8000 rpm then too heavy rollers that might hold it at 7000 will feel slower and lazy or too light rollers might hold it at 9000 rpm will feel revvy
quite often mid component life fixes on auto,s just mask a combination of worn component issues and returning to new rollers belt and spring will cure it
parts approx £45/£50 and labour yourself or workshop approx £30