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Main jet for QMB139 CVK 50cc carburetors. Carburetor jets come in different orifice sizes. Carburetor jet sizes are measured in hundredths of a millimeter. For example, a 87 jet has an opening that is 0.87 mm in diameter. An 90 jet has a size of 0.90 mm, etc. 2009 Piaggio Zip 50 will not turn over Hi, Anonymous before testing any electrical component in the Starting Circuit it is 'IMPERATIVE' that you have a fully charged battery of 12.5 volts or more and be able to pass a proper 'LOAD' test if necessary, you may have a preliminary reading of 12.5 volts or more but little or zero amperage, the battery is faulty and must be replaced.
I decide to make derestriction of my Aprilia SR 50 with carburetor 2011 year (i bought it brand new at 06.062012). After removing limiter from carburetor it is necessary to change jet size. What size of the jet is a good choice? I know exactly that it must be larger than 70.
My exhaust wil be stock, and filterbox will default. I will remove only washer from variator and air limiter from carburetor. I know that i can use 80 or larger, drive about 10 km and check sparking plug condition.
But it is difficult. After main jet changing is it necesarry to make some tune of carburetor? I think it doesn't. Thanks a lot for any help. Im a bit off confused at the moment, this is another bike that has got/had a restrictor in the carb! There usually an open carb with no restrictions. This 09 and my friend 11plate SR50 have them in.
New restriction maybe? It is old restriction. If you get service manual on Aprilia SR 50 for 2005 year you can find this carburetor limiter on explode view of carburetor. There is no name of this part on that explode view. It is metal plate with 4-5 holes and it put into carburetor input. On russian forum i get advise to try a jet with size between 65 and 75. Default size of the main jet is 53.
It is possible that jet with size 60 is the best choice. But it is possible to kill engine with depleted mixture. My 08 Aprilia Sr50 Street(piaggio engine) had a aftermarket exhaust with 80 jet, after removing the air filter restrictor it needed 88 jet, so if your tuning shop has 65 get it and try it out.
If it does not rev well et splutters its too big. For the exhaust, you will need an aftermarket exhaust to get rid of limiters, most aftermarket exhaust come with small restrictors that can be easily removed with a drill or dremel. Of course with a aftermarket exhaust you will need to rejet to around 80 and retune the variator. My 08 Aprilia Sr50 Street(piaggio engine) had a aftermarket exhaust with 80 jet, after removing the air filter restrictor it needed 88 jet, so if your tuning shop has 65 get it and try it out. If it does not rev well et splutters its too big. For the exhaust, you will need an aftermarket exhaust to get rid of limiters, most aftermarket exhaust come with small restrictors that can be easily removed with a drill or dremel. Of course with a aftermarket exhaust you will need to rejet to around 80 and retune the variator.
Simple question. Why would you want to remove the airbox restriction?!
Its unbelieveble. My friend who use 70 jet try to return air box restriction and scooter become alive. He use Technigas exhaust pipe, i use stock without de-restriction it. Than he was try 80 and it is better than 70 with restriction, engine didn't stop. And than he tried 95 its better than 80. Colour of his sparking plug is brown.
He want to try 105. I use only 68 without restriction in air box, sparking plug is wet and black. Then sparking plug is wet and black it is mean that mix is very rich.
I dont understand what is going on. My 08 Aprilia Sr50 Street(piaggio engine) had a aftermarket exhaust with 80 jet, after removing the air filter restrictor it needed 88 jet, so if your tuning shop has 65 get it and try it out. If it does not rev well et splutters its too big. For the exhaust, you will need an aftermarket exhaust to get rid of limiters, most aftermarket exhaust come with small restrictors that can be easily removed with a drill or dremel. Of course with a aftermarket exhaust you will need to rejet to around 80 and retune the variator. What is your exhaust pipe? My friend use 95 main jet without air box restriction.
![Piaggio zip 100 Piaggio zip 100](/uploads/1/2/5/4/125407083/646609870.jpg)
Sparking plug was wet. He changed main jet to 80 and sparking plug become white. But with air box restriction his scooter slow down when speed is 50 and more. Not being funny here but there a 50cc Rev&Go. 50mph is a good speed! You can't expect these things to pull like a train all the way to 60-70-80 as some claim there's do. This whole thread is about jetting when the simple answer is, Put a jet in it, Take if for a spin, If it splutter's and ride's like shit and the plug is wet then drop the jet down, Continue to do so until the spark plug looks good.
If you put a jet in and it seems to want to die when you rev it and not really want to go anywhere while warming up very Fast then Increase the jet size again till the plug looks good. There's the answer to this whole thread, If you can't do that the sell the bike or take it to someone that understands.
Oww and to add, There is more than 1 component to a carb, more than one jet and then the needle, All control different amounts off fuel at different throttle positions, Idle 1/4 1/2 3/4 Full. Changing one jet is not going to make a difference to the whole throttle movement. Sorry for the Rant but its getting to be the exacts same question throughout the Forum subsection. Oh sorry not 50 mph, only 50 kmh I have not much time to do this and have no jets. I bought it only today. 82,85,88,90,92,95 sizw. Ill try to minimize the time spand by asking a questions.
I collect information. Thanks for help. Another question. I recieved my Techingas Triops.
It has one restriction in it like in this pciture Is it necessary to remove it before i will set it up? I just want to not doing one operation more than 1-2 times cuz i have no time to spand it with this operation.
I just want to use my scooter to get my body to the job. But i cant trust man in the service center. They are idiots, they dont use dynamometric wrenches and they want money for this shit service. Better i will buy dynamometric wrench for this money. I have to choose to remove air box restriction and exhaust restriction or not to remove it. This is my problem. The man who makes no mistakes does not usually make anything.
Stop to humble me. It is my second bike and the first that i want to tune.
I have no more time to do this, this is my real problem. This exhaust system is compatible with aptilia sr 50 if you look manual. And the seller approve that. But it is not. Some times it happens. But i dont care about it, i bought new one.
Leovince ZX-R. And derestrict it. Please advice me what main jet should i start? I dont want to derestrict airbox. I removed all another restrictions.
I wrote that my friend with out air restriction and with 80 has white sparking plug. Just say what size shoud i start. I suppose as you that removing airbox restriction is pointless. Thanks for spanding your time for my stupid questions. Yesterday i spand with my bike. I remove air box restriction and set 88 main jet. Than i ride bike about 20 km and check the sparking plug.
It was brown. Bike ride bad to 3/4 of throttle. But after 30-40 kmh and if i open throttle full it start as a rocket and has very quick acceleration. It ride about 90-100 kmh. Than i change position of throttle needle to its maximum (it was on the minimum position).
Ride about 30-32 km and check the plug. It was black. It is mean that mix is rich.
What should i do to bring my bike ride well from 0 to 75% of throttle? Another problem is that i cant to tune air screw right. Even i try to tune carburetor with air box restriction. 72 main jet makes sparking plug black. Bike ride as a shit to 50-60 kmh and than it start to accelerate very quick (but not as with 88 main jet and without air box restriction).
It was with full throttle. 72 is too reach with airbox restriction 88 with out it. With 88 but if needle is in lower position sparking plug is brown. But when i adjust needle to highest position sparking plug became black. Cuz throttle is fully opened earlyer than if needle is in lower position. This is cuz stock needle is shit.
Stock needle fit only to stock main jet where is little difference between idle jet and main jet. New dellorto phva 17.5 has A7 needle. Needle from repair kit for carburetor of SUZUKI AD-50 is like A7 dellorto needle. It has the same size.
I will try it next saturday. I only want to know more than i already know. This is cuz i asked you that questions. Some knowledge i cant take from manual or book. I can take it only with my own experience or experience of any expert like you. I work 5 days in a week and cant sex with my bike after job.
Only at weekend. Now i have set of some guy who has tune carburetor. He told me that idle jet 32 main jet 68 and A7 needle with aribox restriction and 70 cc cylinder. But i know that 68 main jet with my set is pretty good to. I will try this set at weekend and write the result here. I only want to know more than i already know. This is cuz i asked you that questions.
Some knowledge i cant take from manual or book. I can take it only with my own experience or experience of any expert like you. I work 5 days in a week and cant sex with my bike after job. Only at weekend. Now i have set of some guy who has tune carburetor. He told me that idle jet 32 main jet 68 and A7 needle with aribox restriction and 70 cc cylinder. But i know that 68 main jet with my set is pretty good to.
I will try this set at weekend and write the result here. You don't have a 70cc kit so why bother?!
I tried a lot of combination i even by new carburetor for gilera/piaggio and use its atomizer with stock carburetor. I tried 60,63,65 main jet with throttle slide with cutaway 40 with airbox restriction.
Its bogging in beginning of 2/4 of throttle position. If i remove airbox restriction than 72 main jet is to weak but A7 needle makes mixture to rich.
When throttle is of after full throttle that rpm became to low. A7 make mixture very rich from 2/4 to 3/4 of throttle position. I try 70,72,78 main jet with 40 slide and A7 needle.
The best configuration that i have is 34 idle jet, 65 main jet (it is possible that 68 will be better, i dont try. I tried 70 it is to rich), A13 needle in highest position (it is possible that middle position is better), and slider with 30 cutaway.
The mixture more rich than highest rpm to remove fail when throttle turn deeply. I changed exhaust system from Tecnigas RS 2 Chrome to Leovince TT. Tecnigas is shit.
Oil was leaking through bad contact of this exhaust and cylinder. And nut was turning off.
Even if I tightening it with 15 Nm. Thanks for you help guys.
Atomizer in stock carburetor is 209HA and in carburetor from sip-scootershop.com has 211FA. Look at the comparing picture. Atomizer with low highest part of tube is racing atomizer.
About atomizer. Yesterday i run my bike on my balcony with gillera/piaggio carburetor and mallossi cylinder kit in first time. It start very well from the second pressing start button. I use a little trick with hose of the vacuum valve to fill carburetor bowl before start. Its reaction on throttle is amazing after stock carburetor. It respond on throttle so fast as injection version i think. Here is video about it.
Stock aprilia sr 50 carburetor is useless. Every one who want to tune aprilia sr 50 should to change stock carburetor and easiest way is to buy gillera/piaggio carburetor. You can buy it here Its price with shipping about 3000 RUB (100$) But you can buy it in Moscow for 3500 RUB.
(116$) I can give you phone number of that man who sold me this carburetor. Or i suppose that this carb fits to but its jetting is unknown. It looks as on link above. Guy from moscow scooter forum told me that on his piaggio zip with AC engine he put 65 main jet and A7 needle and its start to work as it must. I suppose that on his zip was carb as on link above but has some restrictions in it.
My new carb work perfectly on idling, but i need to test it in action. If you dont wont to spend your money you can wait when winter will end:-) To use this carburetor with default settings (IJ 34, MJ 65, needle A7 in middle position, and 40 slider) you should not to remove airbox restriction. Start scooter with mixture screw unscrewed on two turns counterclockwise. If your carburetor bowl is empty just remove the vacuum valve hose from carburetor and suck the air out of it with your mouth or syringe. The carburetor bowl will fill with petrol and engine will start as soon as you want.
It is old restriction. If you get service manual on Aprilia SR 50 for 2005 year you can find this carburetor limiter on explode view of carburetor.
There is no name of this part on that explode view. It is metal plate with 4-5 holes and it put into carburetor input.
On russian forum i get advise to try a jet with size between 65 and 75. Default size of the main jet is 53. It is possible that jet with size 60 is the best choice. But it is possible to kill engine with depleted mixture. This I was told is NOT a restriction and is there to mix the air in better with the fuel.
Can't remember what he said it was called. Mine has it still in and will do over 50mph (speedo ends at 50mph) with a de-ristricted standard pipe and the washer in the variator removed. I was told that mine was running too lean and so he up-jetted it from (I think) a 63 to a 65. However it now runs shite and splutters and wont reach 50 anymore. I can't see how just 2 jet sizes would make that much difference though that is why I am doubting my self a bit on the jet sizes. Any suggestions?
(BTW mine is the Piaggio engine and is a 2012 plate). This I was told is NOT a restriction and is there to mix the air in better with the fuel. Can't remember what he said it was called. Mine has it still in and will do over 50mph (speedo ends at 50mph) with a de-ristricted standard pipe and the washer in the variator removed.
I was told that mine was running too lean and so he up-jetted it from (I think) a 63 to a 65. However it now runs shite and splutters and wont reach 50 anymore. I can't see how just 2 jet sizes would make that much difference though that is why I am doubting my self a bit on the jet sizes. Any suggestions? (BTW mine is the Piaggio engine and is a 2012 plate) this brass plate is not a restriction/limiter,it is a baffle plate!! This brass plate is not a restriction/limiter,it is a baffle plate!! It doesn't metter how it is called.
The main thing is that you must change carburetor to the new one if you want to remove this baffle plate. Because default carburetor was constructed to use with this baffle plate. This carburetor was specially made to restrict bike power. Another words this default carburetor is defective and must be changed to new one. This carburetor is your best choice http://www.sip-scootershop.com/en/products/carburettor+dellorto+phvap2010147.
'It doesn't metter how it is called. The main thing is that you must change carburetor to the new one if you want to remove this baffle plate. Because default carburetor was constructed to use with this baffle plate.
This carburetor was specially made to restrict bike power. Another words this default carburetor is defective and must be changed to new one. This carburetor is your best choice (Nope, it works fine. Ideally with the plate removed you should change the needle to an A12 or A7 to richen things up in the midrange and give the correct part throttle response.
If you buy that carb the only difference will be the needle and main jet. You are wrong. Read my post with number 80, look and the comparing picture some posts before, read Dellorto manual and try to understand why. You can try A13 not A12 needle. A13 is one of the spare parts to this carburetor on easyparts.nl and works better than default A22.
If you put A7 needle on default carburetor mixture will be very rich at the end of the first 1/4 of throttle even if you put 60 main jet and throttle valve with cutaway 40 and atomiser 211FA. Default throttle valve is 30. I tried all this combination and all of them was something like shit. You had better believe me.
Please read whole thread and you will not write this bullshit. If you want adjust default carb you must change throttle valve to 40, idle jet to 34, needle to A7 and mixture tube to something like is on my picture some posts before or any mixture tube with lower upper part. Because Usually the atomisers on Carburetor s intended for two-stroke engines are manufactured in two types: with either long or short upper parts (figure 23). The atomisers with longer upper parts cause a weakening of the mixture at low speeds and du ring acceleration from low speed; on the other hand, atomisers with shorter upper parts produce extra enrichment. Carburetor s for racing motor cycles use atomisers with short upper parts.
Even if you do this it will be worse than to buy the new one. Now i will try to write all defference between default carb and the new one.
236808 And the main thing is that default carb. Has no idle port, only progression port. Gilera/piaggio carb has idle port and progression port. Try to read about this ports in dellorto manual. This difference you cant change cuz it factory based difference. You can try to drill this idle port if you have good tools. And you need to change size to smaller of idle port on default carb.
It is harder then buy the new one just try to believe me. The default carburetor was desined on dellorto factory specially to use with baffle plate. You can try to adjust it but the easiest way is to buy the new one.
And the last difference is the choke jet. On default carb. It is not adjustable, you can only buy the new cap with another choke jet.
Derestricting a Piaggio Zip 50 two stroke 2009 I'm new to the scooter scene and looking for a bit of guidance. Whats the best thing I can do to make my scooter faster., it currently only does 30 mph Heres what I've done and results gained. I took variator ring off and air thingy from carb, I left the bog standard jet which was a size 53 in place. I then fitted a Pedmoto series 2 exhaust and lighter rollers that were supplied with exhaust. On turning the throttle there seems to be a delay in power, but when fully open scooter builds up to speed and powers up to in excess of 40 mph.
The exhaust although looks good is not a great fit despite being suitable for a Piaggio Zip. Very noisy, if you like that thing, but I think it just sounds like a noisy chainsaw and the stand when disengaged strikes the underside of the exhaust.attachment at manifold needs spacers as if you tighten up bolts the attatchment plate bends when tightened fully. Its sealed okay and gas tight I had concerns that main jet was too small as Adrenalin Pedstop recommended a 64, but when i checked sparkplug it was a nice brown colour. Whats the cause in the delay in power when pulling away.its like theres some play in the throttle cable, but theres not.
I changed main jet to a 64 but no difference to pulling away, but builds up to speed and makes about a 10 mph increase. I have now taken exhaust off and replaced it with the original one with catalytic converter, which I modified by cutting off scavenge pipe, crimping and sealing it gas tight.i left new lighter rollers in place and left 64 main jet.
When old exhaust connected it pulls away as it used to do, very nippy but only reaches 30 mph When new exhaust fitted top speed is much better but the slow speed pulling away is compromised.is it a clutch thing or rollers? Got myself a scooter Haynes but Im still baffled.whats my ideal combination for more speed, but without awakening the whole street. Cheers Raymy.
Its the clutch engagement speed and variator adjustment. I suggest installing a tachometer so you can see the engine revs. Then put an adjustable RMS clutch and Doppler variator in the transmission so you can adjust the engagement speed and variator speed. Both can be bought from SIP in Germany if you can identify the scooter model and type. Generally its best to start modifying the transmission and getting it working properly before changing the engine. Without the transmission holding the engine near the top of its powerband, you have no idea whether its running a proper fuel mixture.