33 BHP restiction for V50


Can anyone tell me how I’d go about getting a V50 restricted to 33BHP for a rider who has newly passed there non-direct access test?

Thanks Norman

Hi Norman,
A good V50 will generate around 45 bhp: even the V35 below it knocks out around 35bhp. The practise of fitting a restrictive manifold gasket would not be easy - there’s only a ring gasket sealing the stub inlet to the port. I guess you could have someone machine up an aluminium insert to sleeve down the inlet stubs, but that would have to be with significant jet/slide changes for the bike to run properly.

There isn’t an ECU to restrict.

An easy option might be a physical throttle stop to prevent full throttle - a good dyno operator could set that so only say 32.5 bhp, was ever achievable, but IMHO that might be dangerous to ride - you’d get the initial vee twin pull and suddenly hit a “force field”.

I’d be tempted to insure the bike as cheaply as possible, not use it for the qualifying year, re-insure it with some no claims and use it as Mr Guzzi intended?

If you have not got the bike yet, it is alot easier on the 750 ie as Guzzi make a throttle stop. THe V35 is on the list as a bike legal for progressive access licences without restriction.

Various guzzi intake restriction kits here :http://www.ebay.de/sch/i.html?_nkw=moto+guzzi+drossel&_sacat=0&_odkw=moto+guzzi&_sop=10&_osacat=0Dead easy to install and come with German TUV certification.Never seen them advertised outside of Germany- You could also try Stein Dinse or Teo Lamers.More than likely that the ebayers all speak Englander, SD and TL definitely do !

chris a2013-02-27 22:35:20

The latest V7s make about 41bhp at the wheel, the previous versions 38bhp. Even if the measurement for licence purposes is taken at the crank, the V50 must be close to not needing any restriction?

Can anyone tell me how I’d go about getting a V50 restricted to 33BHP for a rider who has newly passed there non-direct access test?
Thanks Norman[/QUOTE]If the rider has passed their A2 test since 19 January, there is no longer any 33bhp restriction. There is now a min 25kw, max 35kw band which is more like 33 - 47bhp. Bikes such as Honda’s NC700 series are within this range, so a V50 should be good unrestricted.https://www.gov.uk/rules-motorcyclists-83-to-88/motorcycle-licence-requirementsIf they passed on a 125 before this, then they are are in the old position of not having to take any more tests. After two years elapse, they magically acquire a full licence…but until then they are subject to a 25kw/33bhp restriction…and the answers above apply… plus there’s an expensive trade in dyno documents to prove the restriction is effective…Bikes officially suitable for the new ‘A2’ bike test
(Not final)BMW G650GSBrough Superior!!!Gilera Fuoco 500Honda FX650, NC700, Shadow, SLR650 and VT750SHusqvarna TR650 Strada and Terra (restricted), TE449 and TE511Kawasaki ER5, ER6-F, ER6-N, Versys, VN900, (all restricted) and W800KTM Duke 690 (restricted)Moto Guzzi V7Suzuki GSX650F, Gladius, SV650, VL800, VZ800 (all restricted) and GS500Yamaha MT-03, TMAX, XT660R, XT660Z Tenere and YP400 Majesty.New Rules:- YouTube!
EasyTiger2013-02-27 23:53:03

Lot of ideas and info here. I was asking for a work colleague who hasn’t yet taken his test (A2?) Hope is to get him a cheap V50 needing a bit of work which he can work on and value enhance whilst waiting to take his test and for the 2 years after, thenhe can buy a bigger Guzzi I’ll pass on EasyTiger’s comments and get him to check out the minefield of regs to see how he will stand should he take his test later this year. Thanks for the input - anyone know a suitable V50 please pm me. Normski2013-03-01 12:59:17

i’ve also been considering the restriction of a v50 to 25kw. It seems that the technicals have already been worked out, in this military version: http://dekker-expeditions.gotdns.com/dexweb/Guzzi.htmDoes anybody have any idea how they were de-tuned? What is the best way to get technical details from Moto Guzzi? Is there a British subsidiary company, or would i need to contact head office in Italy?

Plenty of information available to download at The Guzzitheque Manuals, handbooks etcFrom the link you posted, the power output is described as 25Kw so you should be OK

Thanks, I’ll take a look. I don’t know if i should rely on a website like that. I’d be more comfortable if i had the info direct from MG.

The Nato V50 you have given the link for above is quoted as having 24mm VHB carbs, so maybe that’s how they’re restricting it (with smaller valves possibly), seeing as a V35 has 26mm carbs I think, and a V50 from memory 28mm carbs. You’ll find it very difficult, if not impossible, to get any official technical data to do with restricting power output direct from Moto Guzzi. Maybe try and get hold of a set of 24mm carbs from somewhere, put them on the bike, then dyno it, but it sounds like a long-winded process. Maybe one of the restrictor kits sold on Ebay Germany would be easier?italianmotor2013-03-25 00:25:04

I think you’re right that the german kits would be easier. But they still seem expensive for what they are. I wonder if i could scale a photo and get some made myself?I can’t read German. I wonder what the difference is between:http://www.ebay.de/itm/Leistungsreduzierung-Drossel-MOTO-GUZZI-V50-PB-77-81-37-auf-25kW-/260886428685?pt=Motorrad_Kraftradteile&hash=item3cbe0afc0d  (the hole seems very small for such a small reduction in power)andhttp://www.ebay.de/itm/Drossel-Drosselsatz-25-kW-Moto-Guzzi-V50-PB-/230615454904?pt=Motorrad_Kraftradteile&hash=item35b1c094b8  ?

First one -Google translate:“Power from / to 37/25 kW Renovations: Ansaugblenden Delivery: 25 kW report for Moto Guzzi V50, Fzg.Typ: PB, model year 1977-81, ABE no. A460 including N.01, with conversion parts” Bing translate:"Performance by / on: 37 / 25 kW"Reconstruction: suction aperture “Scope of delivery: Opinion 25 kW for Moto Guzzi V50, Fzg.Typ: PB, model year 1977-81, ABE no A460 including N. 01, with conversion parts” Second one (Google translate): "Opinion 25 kW for Moto Guzzi V50, Fzg.Typ: PB, model year 1977-81, ABE no. A460 including N.01, with conversion parts "Please let us know after the purchase nor the VIN (vehicle identification number as well, which is located on the vehicle frame and the car letter) by email. Please make sure to transfer the number without error because once printed reports can no longer be exchanged.“Installation instructions are included” Looks the same item to me According to that last blurb you get a ‘report’, or at least certification or proof of some sort, presumably this is why it costs so much. HTH

Try and source a Nato V50 and you’re good to go…

I spoke to a nearby garage that has a dyno. Was quoted £110 to restrict any bike to 33bhp. I’ve seen some cheap DIY kits available for some bikes at about £50, but none for guzzis, or some other models. So, for those where a cheap kit is unavailable, this quote sounds quite attractive.

the 33bhp limit NO LONGER APPLIES check out the DVLA website it includes now V750’s so a V50 will be well under.as is the Virago XV535 which is an ideal learner bike especially due to the low seat height.

There is now lists of bikes that are pre approved. as the law has recently changed …again.

Unfortunately, I don’t believe you are correct about the 33 BHP limit. It does still apply to riders who passed their test in the two years preceding the recent law change (in January 2013). The restriction lasts for two years from date of pass. But, for riders who pass a test after the law change, then the 25 kw limit (or 33BHP, if you prefer) is no longer relevant.
welland992013-04-17 00:23:15

The 33BHP limit no longer applies - for this year’s set of changes, but it does if you were one of those who got your restricted licence before the changes and the 2 years aren’t up.And after getting my 1989 Florida restricted at the carbs and with a throttle stop - tested on a dyno to be under 33bhp - all I experienced was loss of power and zero acceleration, didn’t add to my confidence as a new rider to have my bike inexplicably losing power and speed on A roads with Mr Eddie Stobart et al sitting right up my *ss. :frowning: So I took the drastic and pricey option and retook my test this year - it was snowy and bl**dy cold but I’ve now got a full class A. The Florida is now completely as Guzzi intended and I can’t even compare the riding experience to how it was before. I myself know nothing mechanical, but took loads of advice (of course!) from peeps who had 30 years + riding and mech. experience… and you know what, IT DIDN’T WORK. So don’t do it?Hopefully the range of bikes in the new restricted licence category is fairly decent and will give a lot more scope to people than the old 33BHP limit.Or I suppose I could’ve just got a nice modern restricted Japanese bike right from the start …?? :slight_smile: Claire