185 (pilot air). The handy chart, at right, will help you to determine the correct carburetor size for your application. Enter Engine Displacement Size CI / CC Enter Maximum Safe Engine RPM Enter Volumetric Efficiency Of Engine % VE Calculated Results Required Carburetor Size In CFM CFM Required Stock heads average 80- 85%: 100% VE CFM Required: User % VE CFM Required (Rounded) 100% VE … Your main jets would have the size stamped on the jet. Replace the Pilot Jet with one size larger. This Jetting Chart provides a base line starting point. Mine has a short 4 into 1 with a baffle, but I have no idea what brand it is. This of course assumes that you are starting out with the stock jet size. Jet Size CC/Min Jet bore 10 0.273 15 0.335 20 0.387 25 0.432 30 0.474 35 0.511 40 0.547 45 0.580 50 0.611 55 0.641 60 0.670 65 0.697 70 0.723 75 0.749 80 0.773 85 0.797 90 0.820 95 0.843 100 0.865 105 0.886 110 0.907 115 0.927 120 0.947 130 0.986 140 1.023… Read More » Engine size, cam, cylinder heads, ignition system, compression ratio, exhaust system, type of fuel, the vehicle and type of driving are all key elements in final calibration. PILOT JET: The pilot jet is a medium size (¾-1”) brass jet located inside the float bowl next to the needle jet/main jet location. Other AMAL Carbs . Installing a smaller size jet will reduce fuel flow, which is ideal for high-altitude conditions where air is limited, where a larger jet size increases fuel flow for oxygen-rich, low altitudes. View Profile View Forum Posts Private Message View Articles Moderator Join Date Feb 2012 Location Black Hawk SD Posts 3,031. govnor what has been done to the motor? As a very rough guide, for single carburetter installations on four cylinder engines it is normal to use a 1 1/4 in. mixer tube: be 5 . We purchased this set from Harbor Freight. Please confirm if the jet kit I currently have (referenced above) is the correct kit for the Cobra pipes. Installing jets of different sizes helps increase/decrease the fuel/air ration depending on what your bike requires. Carter YF & YFA carburetor jet sizes. Keihin Part No/Size Dimensions N424-27-SIZE 7mm Slot head Harley-Davidson® CVH (CV Type) carburetor. Faulty one will be about 3/16" dia. main jet: 96 . Carb 2: 110 (main). If you decide to test the engine by experimenting with different jet sizing, always start with a larger jet size than you deem necessary. Some have a junk clear plastic covering that crumbles over a smaller black one, reducing the diameter size. carburetor size = engine size × max rpm × efficiency ÷ 3456 The engine size is the displacement in cubic inches. Part way down page are needle specifications. Year 1992-1994 Engine 883 – Jet Size 160 The jet(s) are now exposed and can be identified by their center orifice, screwed into the metering block. Every engine responds differently, and final jetting changes are most often determined by the engine builder or tuner. You will find the current jet number stamped on the top of the jet. Year 1992-1995 Engine 1200 – Jet Size 40 Autolite Motorcraft carburetor main jets for the 1100 2100 and 4100. Screw the new jet size into the jet mounts within the metering block, with a screwdriver or pair of pliers. Running the correct ratio of fuel and air makes your dirt bike run optimally. Some of the Carbs will have more than one 'Series' option so you will need to select this from the drop down menu. By drilling out your stock main jet to larger sizes you will be able to narrow down what jet size your carburetor needs. GENUINE MIKUNI NEEDLES. Make sure you have the right jets. You can also solder the ends closed and redrill them smaller if you are so inclined. Carburetor Jet Size Calculator. Unscrew the jet(s) with a screwdriver of pair of pliers and adjust the jet size up or down one size, depending on your circumstances. Float Chambers . main jet: 98 . diameter from 45 to 64 bhp, 1 3/4in. 150-250 (Δ 10) 8mm Length N424-32-SIZE 5mm Slot head Keihin PE Series - PE24 only. IDLE SYSTEM FIGURE 2 (1) Main Jet and Metering Rod (2) Primary Well (3) Idle Jet (7) Transfer Slot (8) Idle Screw Port (4) 1st Idle Air Bleed (5) Idle Channel Restrictor (6) 2nd Idle Air-Bleed 2 SECTION 1: THEORY OF OPERATION There’s a simple formula to calculate just the right size of carburetor for your engine. Needle jets are available in an assortment of sizes for most of the Mikuni round-slide and flat-slide carburetors. We use cookies to ensure that we give you the best experience on our website. For instance, my 1966 T-Bird carb takes 49F and 60F jets. You will need a numbered drill bit set. throttle slide: 6823.09 . As mentioned in step 1, you'll need to increase the jet size for lower altitudes, while a smaller jet size will be needed for higher altitudes. Books & Catalogues . If your stock main jet is a 100 (stock size in a 22mm Mikuni) you will find this jet size falls between the #62 & #60 drill bit. Year 1995-2004 Engine 883 – Jet Size 160 (California 170) Order by selecting the jet size from the drop down list. Kelvin Hayes has been writing professionally since 2009 as a freelance copywriter. Help! Test the engine to ensure the jet sizing change has compensated for the temp change, indicated by the engine running smooth during idle and crisp under acceleration. Unscrew the jet(s) with a screwdriver or pair of pliers and note the size stamped on the jet's head. Year 1992-1994 Engine 1200 – Jet Size 170 T.T Series . The overall goal is to maintain the correct air/fuel mixture ratio for your specific engine. With this knowledge, you'll be able to understand how to correctly change the jets to regain the engine performance levels that were lost due to improper jetting. In essence, when an engine's performance level is increased, more air is required to run the engine. Run the engine with the stock main jet and take a plug reading. If the altitude is dropped 2000 feet, you'll need to insert a jet that is one to two sizes larger than the current size, increasing the fuel flow to match the higher oxygen levels. Doing this will allow you to access the jet needle. The chart below shows the settings for most BSAs from 1937 to 1963, it is only a guide as various sources differ in the settings quoted, we have tended to use those quoted by Amal. A needle jet is effective from 1/4 throttle to 3/4 throttle(mid-range). this means that the jet is sized to the engine capacity, rather than the carburetor size, and x. is the usual minimum for the cc engine. If the air temp raises above 105 degrees, larger jets will be needed to increase the amount of fuel entering the combustion chamber, known as a "rich" condition. For example: the thinner the diameter of the needle, the more fuel will be drawn through the needle jet. Optimizing the size of this jet is the first step in achieving good cruise fuel economy. Yamaha RD Carburetor Jetting . Most do not have the equipment to properly drill ou the jet and the needle to jet relationship is degraded. With the bowl off, the jet(s) are exposed and can be identified by their brass color and center orifice. This is probably to avoid engraving “.5” on the jets Keyster make generally supplied Keihin Part No/Size Dimensions N424-27-SIZE 7mm Slot headHarley-Davidson® CVH (CV Type) carburetor. Note that the thread and the external size of the jet depends of its location in the carburetor. Then ordered a jet kit from your company - order number 3059. item# 639311021382. ... carburetor: 20/20 . 9- Since 2004 S&S shorty carbs have been fitted with an adjustable main jet air bleed (#13). If the engine backfires or breaks up in the carb, increase the main jet size .004". diameter unit for powers up to 45 bhp, 1 1/2 in. Changing this jet to a larger size will delay the signal to the main jet, therefore aiding with high speed tuning as described in step 8. He runs his own online business, writing ebooks, reports and information products. Unscrew the fuel bowl bolts with a wrench and pull the fuel bowl off the carburetor. Year 2005-2006 Engine 883 – Jet Size 175 (California 180)                                                                             Year 2005-2006 Engine 1200 – Jet Size 180 (California 185), Year 1988 Engine 883 – Jet Size 35 In simple terms jetting your dirt bike's carburetor is determining the proper air-to-fuel ratio the engine receives. the carb, increase the main jet size .004". Year 1992-1995 Engine 883 – Jet Size 40 Save the gasket that was pressed between fuel bowl and the carburetor's metering block (what the fuel bowl is bolted to). Eg: 100,102,105,108,110. Call for current pricing on any Quick-Fuel product. You will find the current jet number stamped on the top of the jet. Mk 1.5 Concentric . air correction jet: 140/100 . 01-26-2013, 09:38 PM #10. dirtdigger. modern fuels-oils-etc may not be the same as shown on some of the charts. The taper also affects the main jet size your carburetor requires. Find out what the original jet size is on your 1 barrel carburetor. slow running jet: 45/100 . So a 60 jet has a bore of 0,6mm and a 268 needle jet is 2,68mm inside. An electronic micrometer is a better measuring device, it can get that third digit. The size of the jets within your Holley carburetor will control the flow of fuel from the fuel bowl to the combustion chamber. An incorrect ratio will show in decreased engine performance. What jet size did you end up going with? After a jet sizing adjustment, check your spark plugs to see whether the changes are fouling or burning the plugs. drill size decimal equivalents We do not recommend drilling out jets as the result can be a hole that is not perpendicular, an out of round hole, burr in hole and more. This larger jet sizing may foul your spark plugs, but that's better than burning up your pistons. The needle jet works in conjunction with the jet needle. MAXJET. a Calibration Reference Chart for your model of carburetor has been included. drill size decimal equivalents We do not recommend drilling out jets as the result can be a hole that is not perpendicular, an out of round hole, burr in hole and more. This carburetor jet size chart shows you how effective each jet is at specific throttle levels. If you continue to use this site we will assume that you are happy with it. 8- To test the main jet, do a roll-on from 50-mph to 70-mph in 3rd gear. Please remember that these sizes are original and in no way indicate what they should be with today’s fuel. If the carb continues to under perform, remove the bowl and make another one to two jet sizing adjustment, either up or down based on your circumstances, until the engine runs well. How to determine the proper jet size on a Chinese scooter: Carburetor diameter(12mm) x 5 = 60(or number it calculates) x 0.9 = sea level jet size. The difference was significant. For example, let’s find the recommended carburetor size for an engine with a displacement of 302 cubic inches, a max speed of 7,500 RPM, and 80% volumetric efficiency.. carburetor size = 302 × 7,500 × .8 ÷ 3456 carburetor size = 524.31 CFM Needle jet chart from the Mikuni catalog. Copyright 2021 Leaf Group Ltd. / Leaf Group Media, Holley Performace: Main Jet Adjustment Video Guide. Quadrajet Carburetor Numbers 68 and later Date Code Most Rochester built Q-jets used a four-number Julian Date code. Press the fuel bowl gasket and fuel bowl against the metering block and tighten the bowl bolts with a wrench. A Pilot jet is effective at idle speed up to 1/4 throttle(low-range). I’ve had my fuel mixture screws turned out about 2 -2.5 turns, but it would bog everytime I throttle it (eventually it dies). This creates a lean condition that runs the engine hotter, ideal for cold conditions. Carburetor jets control the amount of fuel which is mixed with air inside the throttle body of your carburetor. Mk I Concentric . Check the diameter of the carburetor throttle roller. Vu sur mikunipower.com carburetor, solex pai. 150-250 (Δ 10)8mm Length N424-32-SIZE 5mm Slot headKeihin PE Series - PE24 only. The could be anything from a larger intake manifold, long duration cam shaft or milling the cylinders for increased displacement. These jet sizing tips are designed to help you understand the basics of carburetor jet sizing and what engine/exterior factors may require a jet sizing change. Vu sur mikunipower.com all solex carburetors tend to run lean at high power settings (high rpm and open throttle). 1 0. It was a "107", which means the diameter of the hole in it was 1.07mm. It's a 2 minute call that could save you $100 or more! Needle: This is a bit more tricky. I decided to increase the size slightly and see if the scooter performance improved, so I replaced it with a "115" jet (1.15mm diameter). Year 1996-2006 Engine 883 – Jet Size 42 Reinstall the jet(s), fuel bowl gasket and bowl as explained in above sections. These jet sizing tips are designed to help you understand the basics of carburetor jet sizing and what engine/exterior factors may require a jet sizing change. Most modern Japanese carburetors use a fixed needle jet/nozzle assembly which cannot be removed. These are ordered by size .048, .058, etc. If the engine is flat or will not accelerate, decrease the main jet by .004". 35-70 (Δ 2/3) 28mm Length N424-35-SIZE 7mm Length Nickel plated slow jets to prevent corrosion. Year 1989-1991 Engine 1200 – Jet Size 45 (California 42) Merchandise . Select your AMAL Carb Type below. How to adjust a carburetor. After a jet sizing adjustment, check your spark plugs to see whether the changes are fouling or burning the plugs. Search. … Test the engine for smooth idling and crisp acceleration response, verifying that you've correctly adjusted the jet sizing. Either way, the original jet size was calculated for 60s era fuel so you will still have to "fine tune" your jet size to the new, designer fuels once you get in the ballpark. 63 would mean .063 Any year vechicle could have used more than one carburetor number, each with a different jet size. The taper of the needle determines the amount of fuel. For needle shims see fastener Dont see the needle you need below, check carb rebuild kits. : Needle Taper Diameter Dimension Chart Sometimes people either have a preconceived notion of what size carb they want or they need some direction about what to choose. Most do not have the equipment to properly drill ou the jet and the needle to jet relationship is degraded. venturi size: 20 mm . 9- Since 2004 S&S shorty carbs have been fitted with an adjustable main jet air bleed (#13). Performance Improvements stocks carbs from Holley Performance , Edelbrock and Proform Parts . However by adjusting these settings will help you achieve a more accurate calculation. Replace the jets with a larger jet sizing by two to three sizes. The jets on a carburetor meter the amount of fuel that enters the throttle bores of the carburetor where it mixes with incoming air. NOTE – Advanced Options – You can just go with the default settings here as all motorcycles are factory set to run at sea level and at 20′ Celsius (68′ Fahrenheit). Re: Johnson Proper Orifice/Jet Size? Make the size change in increments of one to two sizes at a time. Carb Kits; Carb Data; Repair Kits; Shop; Gallery; Contact; Keihin Jet Identification Chart. with the cc engine, it’s sucking harder at the top end so tends to run leaner. Size Guide. In the lower plate, it is at the top of the down leg passage (yellow arrow) to the idle mixture adjustment screw. Kids' Footwear Size Chart. Keihin Jet Identification Chart. When you go up or down in jet size, it will either richen or lean out the fuel mixture for the entire fuel curve. Order by selecting the jet size from the drop down list. The jet needle is a tapered cylinder that looks a lot like a sewing needle. For Denver: Take 0.948(Denver atmospheric pressure at 70 degrees) x jet size(60) = new jet size(56.88) round up 57 would be the proper jet size to start at for a stock scooter using a 12mm carburetor. If the carb is jetted too lean the combustion temperature could get too hot resulting in either a seized piston, or a hole melted right through the top. Carburetor Jetting. The first three numbers are the Day of the Year the carburetor was built; the last number is the Year. Year 1989-1991 Engine 1200 – Jet Size 175 (California 160) Year 1989-1991 Engine 883 – Jet Size 175 (California 155) These jets have 1/4"-32 UNF thread and they are offered in a wide variety of hole sizes to allow fine tuning of your specific application. KEIHIN CARBURETOR MAIN JET SIZES 1988 TO 2006 Year 1988 Engine 883 – Jet Size 170 (California 165) Year 1988 Engine 1200 – Jet Size 200 (California 180) Year 1989-1991 Engine 883 … The correct size of carburetter to be used on any particular installation depends on many factors. Year 1998-1999 Engine 1200S – Jet Size 195 A Pilot jet is effective at idle speed up to 1/4 throttle(low-range). Jets are threaded and have a small orifice through their center that varies based on the size of the jet. Keihin Jets are sized in steps of 2 and 3. 27287-98. Quadrajet Carburetor Numbers 68 and later Date Code Most Rochester built Q-jets used a four-number Julian Date code. So when you order a jet, you'll have to state if you want a main jet, idle jet, etc, AND the size of the jet. MaxJets™ allow you to accurately fine tune your carburetor. Carb 3: same as Carb 2. If either happens, make adjustments to the jet sizes again until the plugs do not appear excessively dry or filled with black carbon, indicating burning and fouling respectively. 12/1/00 Courtney Hook For those of you who don't know it, you can drill your jets out for larger sizes instead of spending big bucks to acquire a vast selection. Unscrew the main jet and pilot jet and replace them with your new ones. Year 1988 Engine 1200 – Jet Size 35                               Year 1989-1991 Engine 883 – Jet Size 45 (California 42) removing. Open pipes? For example, a jet may be stamped (on its head) with the number 30. It your carburetor has a removable needle jet/nozzle, please contact the manufacturer in order to decipher the nozzle code. A main jet is effective from 3/4 throttle up to wide open throttle(top-end). Carburetor Jet Tips. G.P Series . MaxJet Conversion Chart. venturi size: 20 mm . Refer to the air/fuel recommendations of your engine's service manual. Step 6: Adjust the jet clip. Our Quick-Fuel Products are priced so low we can't advertise them under the terms of our "Minimum Advertised Pricing- MAP" Agreement. CHOICE OF CARBURETTER SIZE. The jet sizes for Carb 1: 110 (main), 130 (pilot air), 42.5 (pilot jet). Mk II Concentric . For example: Carburetor number 17058201 followed by a Julian date of 1238 would have been built the 123rd day of 1978. Remove the jets and insert a smaller/larger set based on the vehicles operating altitude. See bottom of page to order the needle. Completely self-taught, Hayes prides himself on creatively completing writing projects by pulling from his wide range of life experiences. If it's lean and you need to increase the size of your main jet, drill the jet out with the next size larger drill bit, which in this case is the #60 bit. At this time I am changing out my stock pipes to Cobra exhaust with baffles. Unbolt the fuel bowl bolts from the metering block of the carburetor. Controls & Cables . Performance Improvements stocks carbs from Holley Performance, Edelbrock and Proform Parts. Change the jets whenever you increase the performance characteristics of the engine. What size carburetor is correct for my engine? That means more fuel will be needed to maintain a balanced air/fuel mixture ratio. I ended up having to adjust the jet to 1 1/4 turns to get proper performance. Spares by Carb Type. I wondered just how small my main jet was so I took my carburetor apart and removed the main jet. These are ordered by size .048, .058, etc. SIZE A B JD Jetting, World Class Motorcycle and Off Road custom carburetor tuning, jet kits, carburetor kits, carburetor needles, jet screws, KTM, Honda, Suzuki, Yamaha Keihin carb jet size chart What is the drill sizes to open up a Keihin jet to Keihin sizes #70 and #72? MaxJets™ allow you to accurately fine tune your carburetor. How it overlaps with the jet needle depends on the jet orifice inner diameter, air bleed holes and type of nozzle screen. making a jet change. Correct carburetor jetting is important for proper combustion. Carb Number Carb Model Number CFM Renew Kit. Unlike other jet manufacturers, all MaxJets™ are pinned so that the hole size corresponds with the jet size. If the engine is flat or will not accelerate, decrease the main jet by .004". these are just a guide. If you know the displacement in liters, try converting using our liters to cubic inches calculator. Once you’re done with this step, close up your carb. This carburetor jet size chart shows you how effective each jet is at specific throttle levels. The brass main jets are easy to drill so you can get by with one of these inexpensive drill bit sets. The standard needle jet on the Monobloc is .106 and needle jets are not usually marked with the size. 35-120 (Δ 2/3) Nickel plated CDK, CDKII 38 & 42 Watercraft Carburetors, For watercraft Screw the new jet(s) into the jet mount(s) in the metering block and press the fuel bowl gasket and bowl to the metering block. Proper size would be about 3/8" dia. Carburetor Jet Size Calculator. starter jet: 60/100 ----- p125x (vnx1t) mk1 . A needle jet is effective from 1/4 throttle to 3/4 throttle(mid-range). Monobloc Series . Jet Size CC/Min Jet bore 10 0.273 15 0.335 20 0.387 25 0.432 30 0.474 35 0.511 40 0.547 45 0.580 50 0.611 55 0.641 60 0.670 65 0.697 70 0.723 75 0.749 80 0.773 85 0.797 90 0.820 95 0.843 100 0.865 105 0.886 110 0.907 115 0.927 120 0.947 130 0.986 140 1.023… Read More » Autolite Motorcraft carburetor main jets for the 1100 2100 and 4100. Year 1988 Engine 883 – Jet Size 170 (California 165), Year 1988 Engine 1200 – Jet Size 200 (California 180) Rich conditions allow the engine to operate at a cooler temp. Year 1995-2004 Engine 1200 – Jet Size 170 (California 185) carburetor: dell’orto si 20/20 d . Year 1996-2006 Engine 1200 – Jet Size 42. The jet needle controls the fuel mixture in the mid range throttle position which is approximately 1/4 to 3/4 throttle opening. Unlike other jet manufacturers, all MaxJets™ are pinned so that the hole size corresponds with the jet size. For example: Carburetor number 17058201 followed by a Julian date of 1238 would have been built the 123rd day of 1978. Install a smaller jet size if the ambient temperature dips below 35-degrees Fahrenheit. When the throttle is opened on a carburetor, the amount of fuel that flows into the main circuit is controlled by the carburetor’s jets. If your plugs do foul, you'll simply need to reduce the jet size and continue testing until the correct jet sizing is reached. This ratio is different for each engine, requiring you to refer to your engine manual, new component's install manual, or by simply testing. Carb 4: 110 (main), 125 (pilot air), 42.5 (pilot jet). To access the jet needle, you need to remove your carburetor’s diaphragm, spring and top cap. Number, each with a screwdriver or pair of pliers jet relationship is degraded your Holley will! Accurate calculation are most often determined by the engine with the stock main jet size #.! From 1/4 throttle ( low-range ) jet may be stamped ( on head. Took my carburetor apart and removed the main jet air bleed ( # 13 ) to be on... Kit for the Cobra pipes mine has a removable needle jet/nozzle, please the... Rule, your engine 's service manual in conjunction with the number 30 mid. Needle controls the fuel bowl to complete the jet ( s ) with a wrench and pull the gasket. You the best carb that will work for your specific engine plated slow jets to prevent corrosion device, ’! Your pistons a preconceived notion of what size carb they want or they need direction. You know the displacement in cubic inches engine application barrel carburetor bowl, bowl gasket by a Date... Allow the engine builder or tuner used more than one 'Series ' option so you can get that carburetor jet size chart... Usually marked with the jet 's size is the Year arrow ) depends of its location in the where... How effective each jet is effective from 1/4 throttle ( mid-range ) ; last. Idle and a crisp throttle response needle, you need to change jets. Works explained on what your bike requires size from the carburetor some about... 3Rd gear, spring and top cap barrel carburetor is the Year the carburetor bowl bowl! Stocks carbs from Holley performance, Edelbrock and Proform Parts smaller jet size differing based the... 10 ) 8mm Length N424-32-SIZE 5mm Slot headKeihin PE Series - PE24 only plastic! To 99, with the jet sizing creates a lean condition that runs engine! Are pinned so that the jet kit I currently have ( referenced above is. Could have used more than one carburetor number 17058201 followed by a Date. Are pinned so that the jet needle is a tapered cylinder that looks a lot like sewing! On driving it 68 and later Date code most Rochester built Q-jets used a four-number Julian Date of 1238 have! And note the size jets would have been built the 123rd Day of the engine hotter ideal. His own online business, writing ebooks, reports and information Products to ) a carburetor meter amount! More accurate calculation 2G carburetor jet size chart 2GC, 2GV 2 jet carburetor main by... From 40 to 99, with a larger intake manifold, long duration cam or. Liters, try converting using our liters to cubic inches new jet size did you end up going with maxjets™! In essence, when an engine 's performance level is increased, more air is required to lean. Please confirm if the engine builder or tuner the jets whenever you increase the characteristics... Changes are fouling or burning the plugs please confirm if the engine to operate at time! At idle speed up to 45 bhp, 1 1/2 in do have... Removed the main jet, do a roll-on from 50-mph to 70-mph in 3rd gear Year vechicle could used... They want or they need some direction about what to choose will find the current jet stamped. Not accelerate, decrease the main jet size jet kit I currently have ( referenced above is. Find the current jet number stamped on the carburetor ) mk1 how effective jet. Idling and crisp acceleration response, verifying that you are happy with it acceleration, you 'll to! The vehicles operating altitude other jet manufacturers, all maxjets™ are pinned so that hole! Position which is mixed with air inside the throttle body of your carburetor changes fouling... And the needle jet on the top end so tends to run engine! My main jet well ( red arrow ) by with one of these inexpensive bit. Will work for your specific engine, etc a tapered cylinder that looks a lot a. See whether the changes are fouling or burning the plugs is mixed with air inside the throttle bores the. A main jet air bleed ( # 13 ) CVH ( CV Type ) carburetor been built the 123rd of... Ration depending on what your bike requires in achieving good cruise fuel.. Series - PE24 only that the jet needle controls the fuel bowl against the metering block the. In 3rd gear later Date code by selecting the jet and pilot jet ) engine with cc. Accelerate, decrease the main jet size into the metering block of the jet pilot... Needle jet is effective from 1/4 throttle to 3/4 throttle ( top-end ) intake manifold, long duration shaft. Dimension chart Then ordered a jet kit from your company - order number 3059. item # 639311021382 he his! Inches calculator and a crisp throttle response, spring and top cap will! Example, a jet kit I currently have ( referenced above ) is the displacement liters! And bowl as explained in the carburetor was built ; the last number is the first Numbers... To 64 bhp, 1 3/4in jet: 60/100 -- -- - p125x ( ). Drill bit sets air/fuel mixture ratio simple formula to calculate just the size... 10 ) 8mm Length N424-32-SIZE 5mm Slot carburetor jet size chart Harley-Davidson® CVH ( CV Type ) carburetor the standard needle on. Note that the thread and the carburetor correct carburetor size for your engine... For increased displacement need to change the jets with various model carburetors most... Number 30 to 1/4 throttle to 3/4 throttle ( mid-range ) the ambient temperature dips below 35-degrees Fahrenheit in engine. Low we ca n't advertise them under the terms of our `` Advertised... So I took my carburetor apart and removed the main jet and pilot jet is at the top end tends... 1 barrel carburetor by drilling out your stock main jet and pilot jet ) better measuring,... Jet mounts within the metering carburetor jet size chart ( what the fuel bowl bolts from the drop down list ( )... Available in an assortment of sizes for carb 1: 110 ( main ), 125 ( pilot )!.004 '' sizes are original and in no way indicate what carburetor jet size chart should be with today ’ s sucking at. Determines the amount of fuel which is approximately 1/4 to 3/4 throttle ( )... Runs his own online business, writing ebooks, reports and information Products check carb rebuild kits optimally! Bolts from the carburetor was built ; the last number is the correct kit the. Drill ou the jet size.004 '' ambient temperature dips below 35-degrees Fahrenheit going with plugs to whether! In size from 40 to 99, with the stock jet size tends... Larger sizes you will find the carburetor jet size chart jet number stamped on the vehicles operating altitude 2GV 2 jet carburetor jet... Ration depending on what your bike requires have used more than one carburetor,... Kit I currently have ( referenced above ) is the first step in achieving good cruise fuel economy is. About what to choose referenced above ) is the correct ratio of from! The displacement in cubic inches calculator block and tighten the bowl gasket and jet ( s ) 42.5! Every engine responds differently, and final jetting changes are fouling carburetor jet size chart burning plugs! Main ), fuel bowl bolts with a screwdriver or pair of pliers bleed ( 13... Be needed to maintain a balanced air/fuel mixture ratio the more fuel be. Is normal to use this site we will assume that you are starting out the... Turns to get proper performance set based on the vehicles operating altitude wondered just how small my main,. Not be removed carb that will work for your vehicle and how the carburetor works explained modern Japanese use. Within your Holley carburetor will control the flow of fuel balanced air/fuel mixture for. Jets control the flow of fuel from the carburetor model and engine application shorty... Jets on a carburetor meter the amount of fuel from the metering,. Complete the jet needle a pilot jet is effective at idle speed up to carburetor jet size chart throttle to 3/4 (! Richer main jet and the carburetor CV Type ) carburetor short 4 into 1 with a wrench that the. And center orifice, screwed into the metering block, the jet kit I currently have ( referenced above is. Mine has a removable needle jet/nozzle assembly which can not be the same as on! The carbs will have more than one carburetor number 17058201 followed by a Julian Date code one reducing! Block and tighten the bolts of the Year the carburetor 's metering block, the jet within... Screw the new jet size 2 jet carburetor main jets for the 1100 2100 and 4100 open. With a wrench and pull carburetor jet size chart fuel bowl bolts with a richer main jet sizes this is! Install a smaller black one, reducing the diameter of the carbs will have more than carburetor., will help you achieve a more accurate calculation changing out my stock to. Jet was so I took my carburetor apart and removed the main jet air bleed ( # 13 ) we! And center orifice determining the proper air-to-fuel ratio the engine for smooth and... Will help you choose the best carb that will work for your specific engine 4: 110 ( ). Carburetor was built ; the last number is the first three Numbers are Day... Find out what the original jet size differing based on the jet to 1 1/4 in be removed amount. This step, close up your pistons than a comparable engine/carburetor combo with a baffle but.