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Post by rgcgeoff29 on Jan 11, 2016 15:43:21 GMT
Px Guru, I absolutely agree with you, don't get me wrong. I was just digging in my mail box and sharing the informations I had 2 years ago, it was the opportunity to give you the contact of this guy Matt Cooper.
I perfectly understand what you are doing with Sime, no worries. As I told you previously, I m wortking now for more than 2 years about all sort of combinations to sorted out the best compromise with these SI Carbs. And while I was investigating I found disturbing informations.
During the years, Vespa changed the 24/24 SI set up. The following show you the different interactions (I added the T5 and the cosa 200) These informations have fueled my curiosity. That's why I did contact Dellorto to try to understand
model year Air Corr. mixer tube MJ IJ Slide P200 1987 160 BE3 116 55/160 (2.9) n°9 P200 E et Px200 1988 160 BE3 116 50/160 (3.2) n°4 P200 E et Px200 1989 160 BE3 116 55/160 (2.9) n°4 P200 E et Px200 1989 160 BE2 118 55/160 (2.9) n°4 Px200 E 1989 190 BE4 116 50/120 (2.4) n°4
T5 1986 120 BE4 110 50/100 (2.0) n°5
Cosa LX 200 1987 160 BE6 92 48/140 (2.9) n°8 Cosa Lx 200 1988 160 BE3 92 48/140 (2.9) n°1
My point of view is you must have all the data of a problem to try to solve it. In this case, the engine never changed, it was always the same base.
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Post by rgcgeoff29 on Jan 11, 2016 11:02:26 GMT
Here a copy of the informations by Matt COOPER at DELLORTO UK : "Throttle slides - the higher the number the weaker it is up to 8th throttle There are two different types of idle jet, 9982 has an adjustable air calibration. This affects things in the upper part of the idle range, there is a chart here: www.dellorto.co.uk/merchandise/products_details.asp?PartNo=9892&CategoryID=2&PartsectionID=69With the atomisers, we haven't got much information except that the holes at the bottom supply more fuel to the lower rev. range and higher ones to the upper rev range" For those who would like to contact him to deepen the question : Matt Cooper @ Eurocarb Ltd <sales@dellorto.co.uk>
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Post by rgcgeoff29 on Jan 8, 2016 15:03:16 GMT
An interesting sketch to understand ho are the interactions between different organs of the SI carb
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Post by rgcgeoff29 on Jan 8, 2016 14:45:43 GMT
these SI carbs are a real enygma, I m wortking now for more than 2 years about all sort of combinations to sorted out the best compromise. I even contacted DELLORTO France Italy and UK to have answers.
I was asking about the relationship between air corrector and throttle slide (actually there are 9 different just for the 24/24 si + 4.1 and 4.2 created by SIP) The only answer I had was from Matt Cooper at Dellorto Uk and even this answer was not really satisfying : "higher is the n° of the throttle slide, weaker will be the mix..."
Changing the air corrector jet affects the main jet at wide open throttle. In the mid range the air corrector has little effect and the mix is related to the main jet and mixer tube.
At wide open throttle a smaller air corrector will richen the mix (it reduces the air and can also increase suction to pull more fuel) and larger air corrector will weaken the mix
So, the more important : we know that the idle jet is providing lubrication from idling to wide open throttle.The problem with people who seize up is that they usually just upjet their main jet, and that's not enough...
For me the answer for my POolossi was a 26/26 Pinasco Si carb. MJ is 140, IJ is 50/120 (2.4) 1 turn and half mixer BE3 Air Corrector 150 slide throttle n°4 modified to open fully T5 air filter (larger with venturi inside ) Float chamber with 5.2 mm needle (cosa) enlarged fuel hose connection
No rubber connection to the frame, I changed it for a Polini moss air filter
But, what is working on this engine is totally different on every engine I did build so...
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Post by rgcgeoff29 on Jan 8, 2016 11:23:25 GMT
Hello guys, and thanks for the welcoming. I read with a lot of interest your posts and if I can participate, I will.
Henri : the Lammy is own by Matt Thompson, a mate of my club. Where exactly in Brighton ? I must go to Shoreham by sea to met some friends (Alex Pease) soon, I will let you know.
Jacktheripper : which one mate ?
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Post by rgcgeoff29 on Jan 4, 2016 17:57:32 GMT
I would say directly Taffspeed, for the T5 it's the best exhaust. I did try JL and it's not giving satisfaction, I tried the GF ptoject Compact too, it's ok in town (but very noisy) but not on the road, it's not releasing all the power of the engine.
I didn't try any PM on my T5 but at the moment I m using a Sterling which is actually not bad at all.
For the jetting, I don't know, what is your carb jetting with the 152 ? Usually you upjet 5 points to begin and after you make adjustments. With my 162 Pinasco I use a 26/26G my main jet is 122
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Post by rgcgeoff29 on Jan 4, 2016 16:02:07 GMT
Happy new year to everybody !! So I m Geoff of the RGC I leave in Brittany, member of the Vulcan Celt in Brighton area. I m 45, I ride Vespa since 1984, I used to work in Andrea Finetti Vespa workshop in Paris in the 90s. I discovered some very interesting threads about the DR 177 on this forum and then decided ton sign up. I ride a 1972 GTr that I own since 1989, the engine is a tuned T5 with Pinasco 162 kit and a bit of modifications. I ride another scooter who used to be a smallframe, now extended with p211 Polossi full crank engine One of my passion is preparing engines, in 2015 I did build 8 px 177 for mates, a px 150 (5 ports) and several smallframes for my son and his mates. My FB page is : www.facebook.com/GF.Evrard
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