vespa FUEL BORE widening SI CARB / main jet DRILL | FMP-Solid PASSion |

[@jefft137]

Great video. I had already drilled my 20/20 carb to 2mm to fix chronic fuel starvation on my PX150 before I found this video, but this video will give others great guidance. Note that rejetting was required after this because I was running way too rich after doing this mod, plus adding a float chamber spacer from SIP and a high flow fuel tap.

[@FreakMoPed8]

yep, always near to fuel starvation, its ridicilous. Which cyl in your case?

[@71studs]

Hi I have the same problem after drilling 2.5mm hole scooter runs fine except with the idle jet circuit it now is way too rich and when scooter is taking over it now smokes excessively . due to running in a new dr177 kit i dont want to lower the idle jet i,m using all stock p200 jetting except main jet at 115. It never smoked(rich) at idle previous to boring hole what do you think i can only assume the chamber is now flooding and the fuel pressure is excessive and causing a faster floe into the idle jet???

[@scottgamron351]

As always, this is great info mista Freak! Thanks for talking us through this process, and expending the time and effort to document via video.. I'm going to do this shortly! Thanks again.

[@FreakMoPed8]

you are welcome, happy to help :)

[@JimVanMorrissey]

A fine film as always Jorg. I am loving these.

[@rclavier]

immer gut zu hören! danke FMP

[@knohairknick]

Hi Mr FMP, hope you're keeping cool in this evil hot weather. Malossi 210 plug and play build has started..! Polini box 👍 SIP fast flow 2 👍 Stator slots extended for 18deg ignition 👍 Cylinder fitted 👍 Piston fitted (c-clips very fiddly) 👍 Head fitted. Squish 1mm with 0.15mm base gasket 👍 Carb bore widening 👎👎😭 Got angle a bit wrong and broke through side... Waiting for JB weld to cure, then try again.... Just in case there are any other ham-fisted bodgers who muck this simple task up, I'll report back on how well the repair holds up 🙂

[@FreakMoPed8]

eiei. been there done that! but should be fixable sounda good ur setup🍻

[@knohairknick]

@@FreakMoPed8 2 weeks and all good- no drips 👌 Dropped clutch woodruff key into engine tho 😩🤬 so engine has to be split. As I'm splitting, I have got the K2D mazz 60mm crank. What's the best way to adjust the barrel? I have a 2mm head packer, but I'm not sure if I should add packing to bottom or top of barrel (or both?) I still want this to be as P&P as possible without grinding the barrel ports- but if that is the only way.... Your advice would be really appreciated as ever 👍👍 cheers! Nick 🍻

[@knohairknick]

PS- 2 hours with a strong magnet bonded to the end of some wire didn't find the woodruff key...

[@Clio3RS]

Hab jetzt schon a 128er HD verbaut. Wenn ich diese 2,5mm oder 3mm aufgebohrt hab, muss dann neu abgedüs werden wegen dem größeren Loch Grüße aus'm Salzkammergut!

[@FreakMoPed8]

lass es bei 2.5mm das reicht

[@timthemod]

I love these video, so informative. Is this worth doing for a standard 20/20D or a PX?

[@FreakMoPed8]

for original px200 no need. And a si20 is usually jotnused for tuning, but it can be applied of course, calculate with re jetting as the carba are mostly around lack of fuel, having then enough fuel might need different setting

[@migwelder3492]

Did this trick last summer and it works fine, thanks! Just wanted to know if moving further, what do you think is a proper carb for a 20hp+ build?

[@FreakMoPed8]

details. rotary..reed. exhaust. cyl

[@migwelder3492]

@@FreakMoPed8 preety much a plug&play malossi 210 sport as per your instructions ;) 24SI (drilled), Polini box, Bgm 57mm crank, casings matched to cylinder.

[@vespa_GARAGE_giorgio]

what about some carbs provided from shops with needle ventile , the hole above the needle tip, is around 2,8mm (280) and the needle is 5,2mm than the original 4,5 mm . Do I have to drill it to 2,5mm or maybe at 2,0mm?

[@FreakMoPed8]

Thats all wrong info. Above needle is always 2,3mm, the tip of all needles is the same, only the bodies are different. Px cover is the best. Cosa cover is worse, has a lower flow rate

[@FreakMoPed8]

kzbin.info/www/bejne/apnblKevqZlqosU

[@FreakMoPed8]

kzbin.info/www/bejne/paG9iXV9qslmrNk

[@vespa_GARAGE_giorgio]

@@FreakMoPed8 I am talking about this carb. www.scooter-center.com/en/bgm8571/carburettor-bgm-pro-faster-flow-dellorto/spaco-si24/24e-vespa-px200-type-without-autolube?number=BGM8571 if you see the pictures of the carb you see the numbers I am talking about. You suggest not to use it? because of the coza cover.

[@FreakMoPed8]

i know. they are still selling these in div version for many years. these carbs still do have fuel supply problems. no one can mean +0,3mm serious...

[@paansukarjo90]

hey.. I just finished widening the fuel passage and it is awesome! the problem I had right now is the air filter is so restrictive, I have to remove it.. I have done the filter mod and it is still restrictive. maybe the mesh is too tight, that I have to use different types of mesh. any suggestion on improving it?

[@FreakMoPed8]

Is it the blue LML?

[@paansukarjo90]

yes... it is the blue filter..

[@markrobinson6800]

Ok to do this on my dr180 kit vespa with 24 carb? Thankyou

[@FreakMoPed8]

Yes, makes sense to have for sure enough fuel

[@antoniopapa3353]

Hi,i'm Antonio, I have an lml star, I have mounted the pinasco 177 aluminum central spark plug with 160-be3-106 ..... the 50/160 is better than the 48/160 as the minimum jet possible? I have tried them all 2 .... 50/160 looks better ... I have original si20 carburetor and Megadella V1.2. Should I widen the hole from 1.5 to 2.5mm on the carburetor? If you have any suggestions for improvement ..... thanks

[@FreakMoPed8]

yes, widen the mj bore in any case when it comes to tuning

[@mikeyrimshot]

So I did this procedure and now the bike idles WAY too fast.(PX 150) Idle screw adjustment has no effect. So do I change jet or scrap it? Perhaps I dont have the si carb you refer to, but everything looks same. Thanks

[@FreakMoPed8]

si20 carb? what do you mean with idles too fast?

[@mikeyrimshot]

@@FreakMoPed8 I mean it races ( high rpms) at NO throttle and the idle screw has zero impact. How do you know it is a si 20? Is it stamped on it somewhere?

[@FreakMoPed8]

so too high revs, thats either a too lean idle jet and setting at the mixture screw and or false air somewhere 20/20 or 24/24 is stamped where the hook for the slide is

[@lusso9723]

Great!!

[@nickbarber4222]

Does this drilling effect the idle jet richness?

[@FreakMoPed8]

yes of course. any different main jet already does a bit

[@nickbarber4222]

@@FreakMoPed8 so just drilling the hole from 1.5mm to 2.5mm to improve flow will richen the idle? Even if the jetting has not been changed?

[@malcymal]

If the standard hole inside float chamber is 1.5 mm what is the optimum jet size for 1.5 ? Will a 122 main be ok without drilling. I got dr177 with Road 2 and it’s perfect on 120 main but want to put polini box on. I’m hoping that a 122 jet will accommodate polini box without have to drill carb. Can you advise??

[@FreakMoPed8]

for 122, the standard 1,5mm hole is fine.

[@malcymal]

Will I be able to fit a 122 jet in si24 without having to drill out carb? I have fast flow sip tap installed. Thanks

[@FreakMoPed8]

yes 122 is still fed 100%, above 125 not anymore

[@grahamburke5901]

Finding difficult getting drill bit to the hole, any issue if ends up being 3mm? Using si24/24 with sip fastflow tap

[@FreakMoPed8]

No prob

[@yudhithekid]

Is that possible to install a power jet from carb's bowl into carb's ventury?

[@FreakMoPed8]

What exactly do u nean, whats a power jet from the bowl

[@d.somesh1380]

Thanks

[@seansimpson2586]

same for 20/20 carb? or different size hole?

[@FreakMoPed8]

I rarely use si20 and if just for pnp 177, only a guess 2mm wont do any harm there

[@carnetbydhir4171]

Hello what is The good main jet for this hack i have pinasco 177 ompimized and 125 principal mainjet 130/160 and BE3. What you can help me ?

[@FreakMoPed8]

no, cause details are needed, just the brand of a cylinder does not say anything about the whole engine setup. carb? air filter? with or without holes? exhaust? cyl timings? intake timings? exhaust port shape & width? ignition? :) ;)

[@carnetbydhir4171]

@@FreakMoPed8 i send you message to Facebook

[@maizanlee]

For Si26 do we need to widen the fuel supply hole??

[@FreakMoPed8]

a lot of "26" are only 25, better measure. I recommend checkongbit at every carb, as you cant trust producers and dealers. Ie black did sell for years fastER flow "26" carbs with only 1,8mm bore. also of yellow (i mean its all spaco in the end) is heared that not always drilled fully trough. small check is worth it, as proper fuel is the most important thing for an engine. In the end, everything lives or dies with this bore. (when there is a good fast flow tap, which is often missing too...)

[@matiashalli]

have a two port vespa with a Pinasco 177 cylinder, keep my 20-20 SI carb but with a 115 main jet. Do yo think the invest in a 24-24 carb its ok or with actual setting its ok?

[@FreakMoPed8]

Which pinasco exactly? No, stick 20. Better update the cylinder timings or exchange it.

[@matiashalli]

@@FreakMoPed8 This one, two transfer. -> www.pinascostore.com/en/vespa-sprint-v-150-prima-serie/1625-gruppo-termico-177cc-in-ghisa.html Never touch the rotary valve timming, must go there first?

[@FreakMoPed8]

ok i see. do you have a 2 port engine?

[@matiashalli]

@@FreakMoPed8 Yes

[@surferx66]

Does a stock 2000 px200e need this mod?

[@FreakMoPed8]

no

[@bgmstella8446]

I enlarged the hole to 2.5mm like in this video and now the scooter will not idle and usually dies. The carb is an SI24G. It used to idle well, but now the rpm is very low or dies with the idle speed screw set as fast as possible. The mixture screw has little effect as well. Maybe I drilled too far? I did not drill through the bottom I know. Before modifying it all the adjustments worked normally on the carb, both idle speed and mixture. I removed the idle jet while running and for 30 seconds idled well (much higher rpm) and throttle response was much better and then it dies. Not sure what this tell you. I’ve blown the carb out with air but maybe something is blocked with debris from the drilling. Any ideas before I buy a new carb? Thanks.

[@FreakMoPed8]

if u drill. To deep the carb leaks, thats the only damage u can cause There is enough fuel now, which means ur jets are now fed 100% not only 70% whats ur setup Whats the jetting moat probably your jettingbis too rich. Trx different jets. If the screw doesnt react, the ij is too rich U can use normal longs si jets, An example how close vespa engines are to fuel issues. Original 200cc with polinibox, jets above 122 didnt show any effectmie a 125. serviced AND slightly otuned a 125 was way too rich, the engine was not driveable, it died while trying to start driving

[@FreakMoPed8]

And?

[@paolozak3014]

Strange, I never had any fuel starvation problem whatsoever on any vespa ...are u sure about that ?

[@FreakMoPed8]

depends on the tuning stage. a mj over 125 is not fed 100% anymore cause the 1,5mm original bore is too small. an engine does need too much fuel. Vespas are always around starvation.

[@paolozak3014]

@@FreakMoPed8 I had a 150 converted to 177, and now a 200 vse1m with sip road 2 exhaust, which just needed the emulsioner BE2 instead of BE3, along with a 135 main jet instead of 118. Original carb SI 24/24 & ignition timing 23 deg. Runs perfectly fine....

[@FreakMoPed8]

150/177 the fuel problem does not yet hit in. an original 200 with old sr2 needs mj 120 and thats it. Yes it does run fine, i know. But: neither be2 nor 135 is needed. that mj135 is rideable. Simply confirmes, that you got fuel Flow Problems. would it be 100% fed with fuel, you would nit be able to ride it anymore. as it is rideable = proof of too little fuel. original tiny 1,5mm bore = max mj 125. bigger mj do show little to none effect as there is not enough fuel for them to fully hit in.

[@FreakMoPed8]

try widen the bore to the recommended 2,5mm. If nothing changes, there was enough fuel. If 135 now is not so comfy to ride anymor, there was not enough fuel. kzbin.info/www/bejne/oKaqmH6FeZ6Mptk be2 is just needed for big Expansion and a tuned engine.

[@paolozak3014]

@@FreakMoPed8 be2 & mj135 got rid of the transient ringing when re-accelerating from ca. 90 km/h. Be2 & mj118 (standard) caused ringing at ca. 90 km/h - only slightly with the original exhaust and very pronounced with the SIP Road 2. Doing the obvious thing i.e. backing off the ignition timing would have solved the problem fair enough, but also lost some torque & performance. So I went on increasing the mj : 125 : better torque but engine still ringing 130 : slightly better torque, still ringing but more relaxed 135 : same performance, ringing much decreased and only transient when accelerating from 2/3 to full throttle at ca. 90 km/h Be2 & mj135 : even better torque & response at lower rpm, no engine ringing. I wouldn't go and drill around the carburettor at this stage...

[@amirvaspa]

Plz full vedio down lod

[@FreakMoPed8]

English pls

[@carnetbydhir4171]

You have messenger for talk faster?

[@FreakMoPed8]

u can contact me over my fb page

[@carnetbydhir4171]

@@FreakMoPed8 Thanks i send you message