Piaggio Gilera Vespa Derestriction Guide
Categories: 50cc Tuning, Featured, General How-to's, General Tuning
Written By: admin
Firstly, Piaggio / Gilera / Vespa engines are mainly split into three different types, all produced by Piaggio:
Pre 2000 Piaggio / Gilera engine – No catalytic converter and Dellorto or Weber 12mm carb
2000-2005 Piaggio / Gilera / Vespa engine – Catalytic Converter and 17.5mm Dellorto carb
2005 onwards Piaggio / Gilera / Vespa engine – Catalytic Converter, 17.5mm carb and slightly lower exhaust port
There are minor differences between the Piaggio 50cc engines (which is the same motor fitted in every Piaggio, Gilera or Vespa 2 stroke 50cc machine produced, e.g the Piaggio NRG MC3, Gilera Runner, Piaggio Typhoon, Gilera Stalker, Vespa ET2 50cc, Vespa LX 50cc, Piaggio NRG Power etc) but no real major differences between all the engine versions, just mainly setup changes with the introduction of the catalytic converter into the Piaggio / Gilera / Vespa Exhausts
The pre 2000 engine came with no catalytic converter and a 12mm carb fitted. This engine is getting on a bit now, and there aren’t that many bikes left on the road with it, although I’ve seen more Gilera Runners still about at that age, so I presume they sold a lot better than anything else. Derestricting this engine is the simplist method, done in two parts.
Firstly, the variator requires derestricting to get rid of the restriction on your gearing, and hence top speed. The variator is restricted via a small washer inbetween the front pulleys of the transmission, this stops the pulleys moving all the way together, and is effectively like cutting off 5th and 6th gear if it where to be a geared motorcycle. This is easy to desrestrict just by undoing the outer pulley and removing the washer, nothing else needs changing when doing this. For this derestriction, you’ll need either an air powered impact wrench (windy gun) or a variator locking tool, which can be bought from Machine Mart and any VE-UK dealer respectively.
The second restriction is a small pipe coming off the exhaust which interupts the gas flow slightly, this is not a major restriction and isn’t really that nessecary as I find it isn’t worth the hassle of cutting off and welding over (if you’re doing the derestriction job properly) or the hassle of crimping it tight for the miniscule power benefits it gives. On these pre-cat Piaggio / Gilera engines, no jetting change is required, they come with a 12mm carb and a 72 main jet as standard, this can stay standard even if you fit a race exhaust, only when fitting a 70cc big bore kit must you upgrade to an 80 main jet.
The two post-cat Piaggio / Gilera / Vespa engines have a similar method of derestriction, but can require jetting changes.
Again, the first and foremost restriction is the washer in the variator. Removal of this derestricts your top speed limit as the pulleys are free to work as they where intended too. Derestriction of this part doesn’t require lighter rollers either, contrary to popular belief.
As with the pre-cat Piaggio / Gilera engine, the new post-cat models have one or more restriction pipes coming off the exhaust downpipe, as well as a SAS valve (Secondary Air System). For derestriction, all these can be cut and welded, or crimped. Again I find this a lot of hassle for relatively little performance benefits, it is much better and easy to save up for a performance race exhaust which then shows much larger performance benefits compared to just derestricting the original exhaust. Unlike the pre-cat Piaggio / Gilera models, the post-cat engine (now also fitted in the new Vespa’s too) requires a jetting change when derestricting the original exhaust, and this is where the 2005 split differences on the Piaggio / Gilera / Vespa engine come into play.
In 2005, firstly in the new Piaggio NRG Power scooters, then following Piaggio / Gilera / Vespa models as the production continued, Piaggio had to lower the exhaust port 2mm for emmissions, and the jetting was altered slightly as well. All post-cat Piaggio / Gilera / Vespa models now come with a 17.5mm carb, and either have roughly a 53 or a 56 main jet, depending on whether its a pre or post 2005 model respectively. When derestricting the standard exhaust, you generally go up by 2-3 sizes, so you’ll end up with 56 or a 58 main jet depending on the model. If you choose to skip all the hassle of cutting and welding the standard exhaust to derestrict it, you can fit a race exhaust and just fit a 60-62 main jet instead. I usually reccommend jetting slightly on the richer side for air cooled bikes since they’re cooling system isn’t as good (running leaner with a smaller jet produces more heat), so even bikes that had a 53 main jet in originally could well still benefit from ending up on a 58 or 62 main jet (depending on the exhaust fitted).
July 3rd, 2008 at 3:23 pm
[...] Your scooter has been restricted for a long [...]
August 25th, 2008 at 11:48 am
the restriction on all newer ped’s is no a washer its a cover on the back of the variator held in by 4 or 4 screws all u have 2 do 4 ths restriction is take it off and gain an extra 10 mph well i did
August 25th, 2008 at 7:01 pm
No it isn’t, the REALLY early Piaggio/Gilera models had one, but it’s not a restriction and certainly isn’t on the post 2000 models, I’ve done enough of them
August 31st, 2008 at 5:15 am
I can confirm it as well, it is still a washer.
I have a Derbi GP1 Open, its a model from 2006 with a Piaggio engine and it has a washer restriction which I’ve removed
October 4th, 2008 at 5:44 pm
Hi! I have a brand new Piaggio NRG Power DD (2008 model) and until now it has 900km. I’ve buyed for him: Malossi Multivar 2000 (sport model, not MHR), a Giannelli Extra Chrom exhaust, different tipe of variator rollers (for optimal setup) , a brand new Malossi clutch bell (Wing model), a green and a blue variator springs (Malossi, for optimal calibration), Malossi kevlar belt, Malossi red sponge (for original airbox), Malossi clutch sprins set (i’ll use the yellow ones), NGK iridium sparkplug (br10eix) witth power cable too, and some main jets (62, 68, 70, 72, 80). All parts has been correctly choosen by the code number association wiht my byke. The only problem I have is: WHAT MAIN JET SIZE SHOULD I USE? The 70 one, it’s too big?! I will keep the original 50cc cilinder set and I will do the proper transmision setup (rollers and springs tests) , after i’ll be done with the carburation. Thanks a lot and please excuse my english! I’m waiting for you professional reply. Thanks again! Sorry but I’ve posted this problem in another topic. Please excuse me for that!
October 6th, 2008 at 5:30 pm
You can check your spark plug colour if you got the right jet size.
Should be coffee brown and not white or black.
You can check this after running for some time and at top speed, turn off the engine and get the spark plug out and check the colour.
Note: that the spark plug can be quite hot.
October 16th, 2008 at 2:06 am
Don’t know about how you guys do things in the UK but we got our bikes (Power DD 2008) doing 110km/h (GSP) in Sweden with the original (50cc) cylinders.
Removed restricting washer to the variator
Removed restriction brass plate to the air intake of the 17.5mm carburetor.
Open air filter
0.9mm jet (nice coco color on the spark plug)
Stage6 Pro Replica “exhaust” pipe (Cheap with a low RPM peak) REMOVE THE DARN RESTICTOR!
5g rollers seem to put the RPM in peak range and have a smooth pull from 0-110km/h.
Here is a picture by picture “how to” We never even fitted the 70cc MHR or boost bottle… I am going to put it on my though. http://forum.moppenet.com/showthread.php?t=102810
If you really wanna see some REAL scooter racing check out the video. With 19mm carburetors and 70cc the bikes have about 23.5 bhp.
http://forum.scooterforum.net/forum/f81/stage6-italian-open-awesome-video-156732/
October 19th, 2008 at 11:40 am
You know, you don’t go faster at all with a powerfilter or unrestricted air filter on a 50cc?
You just start using more fuel and you get more noise and as a result you get more cops attention.
My Derbi GP1 50 Open is going at 97 KM/h (GPS)
50cc, Stage6 clutch, Yasuni R (Black Edition) exhaust, Dell’Orto 17,5mm PHVA.
Nothing else changed besides the washer being removed.
http://itchy.nl/files/images/ycscooter/derbi-gp1-open-18-10-2008-007.jpg
http://itchy.nl/files/images/ycscooter/derbi-gp1-open-18-10-2008-005.jpg
October 29th, 2008 at 12:38 pm
Erick,
thanks for the link but don’t understand the language
November 26th, 2008 at 7:59 pm
i have a piaggio typhoon 50cc 03 plate and am looking to tune it up i know about obviously up jetting it and getting a bigger bore and exhaust pipes but do u have any links to sites where i can get transmition tuning parts such as race cluches and lighter rollers and variator stuff and also what jet size to u recommend if i do all of that
November 29th, 2008 at 4:22 am
Just bought a Vespa LX50 and wondered what performance gain is to be expected from the most simple form of derestriction. Not too keen to get into exhaust and jetting changes as I would like to keep the bike looking as standard as possible.
Is just variator plate removal enough?
February 8th, 2009 at 3:50 pm
Hey up,
Sounds like a good guide, anyone have an exploded diagram of a Gilera DNA 50, or any other info about the destrictions?
Heard about CDI’s revs being restricted, true or false? This is the 08 plates, maybe a new restriction?
February 8th, 2009 at 3:51 pm
Hey up,
Sounds like a good guide, anyone have an exploded diagram of a Gilera DNA 50, or any other info about the destrictions?
Heard about CDI’s revs being restricted, true or false? This is the 08 plates, maybe a new restriction?
eu-@hotmail.co.uk
February 25th, 2009 at 1:02 pm
i have taken my bike to a garage and they changed a washer and the gearing and now by bike goes 38mph when it once stayed flat on 30mph.
February 27th, 2009 at 11:14 pm
I HAVE A GILERA ICE 50CC, IVE CHANGED THE EXHAUST SYSTEM. AND IVE
FILE OUT THE JET IN MY CARB. BECOUSE IT KEPT GETTING CLOGGED AND
IN DOING SO ITS GIVEN ME AN EXTRA 25MPH. BUT ITS SLOW ON THE PICK UP.
BUT NOT ON THE TOP END. IS THERE ANY OTHER WAY OV SORTING THIS OUT
OR DO I NEED TO REBORE IT . OR GET 70 RACE KIT.THE SCOOTER IS A 54 PLATE AND IM THE SECOUND OWNER. AND ITS ONLY DONE 9750.
IS THERE ANY OTHER WAY OV GETTING ANY MORE POWER FROM IT.
THANK YOU FOR TAKING THE TIME IN READING THIS.
March 23rd, 2009 at 7:09 pm
hi , my normal bikes broken so i bought a cheap nrg air cooled 50cc scooter as a little run about for the time being .. when i bought the bike it bogd all the way home , i had a few jets tryd a 104 and it still boggd !!! ive now got a 114 jet on a 50cc bike with a standard 17.5mm carb ? ? surely somethings not right ? ?
its got an air filter and vx pipe on it and a polini variator with rollers aprx 4.5 g .. really quick pull off .. but will only do about 35 mph max ? ? its got no restrictor in the manifold .. its got a pipe on it so none there .. and its got 114 jet in it so not there either ? ? please someone that noes what there talkin about help me out !
thanks
March 25th, 2009 at 12:11 am
hi danny. if you can find a standard air box for your standard carb a 58 jet should work but every bikes a lil diffrent so may need to go 1 or 2 sizes bigger.
good luck.
March 25th, 2009 at 4:07 pm
hey i got a piaggio zip 06 i have changed the rollers and apparently has been DE-restricted im not sure how they done this as the previous owner done it it goes 40 mph but only after i have been down a hill i start on a flat road it will go 20 mph then after i have been down a hill it starts to go faster after that. im not sure why its doing this can anyone help how i can make my bike faster straight away
March 27th, 2009 at 11:08 am
who can fit upside downs on 70 nr’s
March 27th, 2009 at 11:13 am
upside downs on fifty frame
April 16th, 2009 at 2:39 pm
this could be many things your air filter may be not letting enough air through but if its a 4t that could be ur problem also your clutch or variator could be damaged
my bike is a piaggio zip 51 and i had the same problem it kicked in at 10 mph but i changed jet down and now it lifts up of mark and hits 60 on flat
good luck
April 24th, 2009 at 1:05 am
i need help, iv got a 50cc gilera stalker (not sure wats been done to it) it sits about 30 on flat ground and can hit just over 45 down hill and the spark plug is black. the guy i bought it off says its got 200cc jets in it im currently at college learning mechanics so iv got mechanical abilitys but know nowt bout bikes any advice to boost acceleration (rubbish on take off hot and cold probably over fuelin) and for flat ground speed
April 25th, 2009 at 8:29 pm
try checking your rollers, as they might be un-even or moved around
May 4th, 2009 at 10:54 pm
ive got an aprilia sr50 2008 model and all i have done to it is a doppler exhaust, washer taken out the variator, new rollers with the exhaust and an upjet from a 53 to a 60.
before i did all these things my bike went nor more than 33mph on a flat and nor more that 40mph down a steep hill.
now, with these few upgrades my bike gets to exactly 60mph on a flat and over 65mph down a hill.
all i had to buy was the exhaust as the rollers came with it and the main jet which came to a total of £118.
definatly worth it!
May 28th, 2009 at 4:15 pm
i own a gilera runner sp50 2008 and would like some help on derestriction i know the stock pipe has extra pipes blocking of emmisions and that need to we cut and sealed and washers in the variator or summin :S? if anyone could help either add me on msn pimpsta745@hotmail.com or email me cheers guys x
May 29th, 2009 at 9:26 pm
hi i have a vespa et4 50cc 4stroke skoot and wanting to bore slash de-restrickt whateverll get me a bit faster instead of snails overtaking me every 5 mins. any1 got tips
jakeblakemore@hotmail.co.uk