Jetting for 26mm Dellorto Carb SI 26/26

Hi, I’ve got a Malossi 210 and just recently aquired a SI26/26 Carb Any idea what size jets I need - I’ve got a ScootRs Pipe the casing have also been matched to the Barrel.
Any help would be grateful before I fit it on and blow up my engine.

No, Sorryi meant do I drill a hole above the main jet/Air Corrector Jet on the bottom of a T5 Air filter not a P2 Air filter. as this is the problem with T5 Filter not sitting properly onto of the body of the Carb.

Hi GP are you saying you have 2 air filters fited or just one in which case what one standard mixer is BE3 so you have a BE5 and it still runs ok .I have a T5 had BE4 mixer was told to put in a BE3 i have done that cant realy tell the diffrence will probely go back to BE4 as scooter has been running with it for 3 years with no problem

Original von Scoota_Dad: The 120 Air correction jet is shorter in length than a 160 Air corrector jet and the 50/100 idle jet is shorter in length than the 55/160 idle jet. because the T5 Carb Body is shallower than the P2 24/24E the air corrector jet and the idle jet from the 24/24E sit higher. Even though the T5 Carb Air Filter is Bigger in height the Jets from the P2 Carb hit the bottom of the Air Filter so the Air filter doesn't sit properly on top of the Carb leaving a large Gap between the Air Filter and The Carb. So am I supposed to Drill a hole Big enough for the Jets To Pass Through in the bottom of the Air Filter or will this cause more problems.

find a work shop with a leath,then ask then to cut the jet to the same size that the T5 lengt …after all the difference betwen T5 and regular jet is just how long is the tube…

i dont know about drilling the p200 air filter i have drill the hole that sits above the main jet on the air filter out to 8 mm this is on a t5 the t5 air filter has a bell mouth so it fits the carb dont know much about the px 200 air filter cant you get a t5 filter should help the carb to breath better

as i said i have drilled the hole out to 8mm the filter all ways sat on the carb ok just drilled it to let more air in as for the jets sitting to high i cant say as my carb has the standard t5 jets a part from 122 main and be3 mixer these fit the same as standard

I did think about giving Beedspeed a ring to see if jet sizes came in different lengths.

Hi, I’ve noticed it is a T5 Carb which has been bored out to 26mm
If I put a 160 Air Correction Jet it is longer than the 120 and so is the Idle Jet from a P2 Carb longer than the 50/100 idle jet in the 26mm and I have a problem getting the Air Filter to sit properly.
So my Question is Do I drill a hole in the bottom of the Air Filter so the top of the jets enter the air filter enabling me to fit the Air filter properly or do I just change the Mixer tube and the Main Jet.
Or Can you get the 160 Air correction and the 55/160 Idle Jets in a shorter length to fit the Carb. Everything else is fine
So Please Can Anyone Help with The Carb Setup Problem.

The 120 Air correction jet is shorter in length than a 160 Air corrector jet and the 50/100 idle jet is shorter in length than the 55/160 idle jet. because the T5 Carb Body is shallower than the P2 24/24E the air corrector jet and the idle jet from the 24/24E sit higher. Even though the T5 Carb Air Filter is Bigger in height the Jets from the P2 Carb hit the bottom of the Air Filter so the Air filter doesn’t sit properly on top of the Carb leaving a large Gap between the Air Filter and The Carb. So am I supposed to Drill a hole Big enough for the Jets To Pass Through in the bottom of the Air Filter or will this cause more problems.

i see what you mean why dont you phone beedspeed or tafspeed and have aword they will sort you out looking at the picture will you have to drill above the idle as well

I have been reading that on wellermans site as far as i can gather the carb does not come all ready to just bolt in and go when scootering done a review of the 26mm carb the t 5 one had a 110 main jet they had to go up to i think some thing like 130 0r 135 that was on a t5 with malossi kit where i have same kit with 24mm carb 122 main jet . i whent on chiselspeeds web site they sell the 26mm carb for £39.95 with standard jets and they will jet the carb for your scooter for another £10.have a look chiselspeed.com

hello,

I have no experience with 26 and Malossi 210, but I would start with a 130 main and get a spare 128 and 132) and will check the ignition is 17 and when sure the carb is set right I will try if 18 is better or not.

as far as i know all the jets should fit both carbs the t5 carb has a shorter boby thats why they have a bigger air filter than a p2

after having my scoot set up on the dyno at taffspeed (it was there for 4 weeks) it came out as follows
malossi 210 with taffspeed modded head
cut crank with oversize big end pin
ported cases
sip left hand pipe
standard electric start flywheel
t5 4th gear
standard autolube
26mm carb
standard air filter (no extra holes drilled) with a ram air filter fitted instead of standard hose as there are problems with the new seat causing a partial vacuum under the seat affecting fuel flow.
petrol cap vent drilled out to 3mm
timing set to px125 marks

jetting is as follows
122 main (you might think thats weak but it runs slightly rich thru the revs according to the gas analyser)
be5 mixer tube
160 air jet
55-160 pilot
mixture screw set at 3 turns out

scoot runs off the clock with my 18 stone and rally gear on it, doesnt pink and pulls well into headwinds and up hills. the sip pipe made a big difference to the way it pulls from 3rd to 4th gear.

[:D]

should have said my scooter has malossi kit and 24mm carb

as you see from the photo, this is where my problem lays with the Jet Sizes

a scooterist on another website is having problems with his 26mm Carb that he has fitted to a Malossi 166 and all he has done is change the Main Jet, which is giving him all sorts of problems. So i’m thinking you need to change the other jets as well.