Carb Jet Size Calculator

I am very curious what a 240, 260, 280 go no/go pins size. Mine was a 49. The jets are located in the bottom of the carb. VE is affected by intake type, camshaft grind and type, boost, and many other factors. If the engine you are working on is equipped with a power valve (no metering rods), the main jet size is what determines the A/F mixture that will be delivered to the engine at light-load/cruise speeds. To figure out the density altitude, you need a weather station to measure the barometric pressure, temperature, and humidity. Let's get to the point on how the carbJetKit Calculator really works. I was thinking 600 CFM but Not knowledgeable on jet sizes. If jets are sized in flow then it’s particularly easy e. One of the nice things about the VM20 carb is that the main jet can be changed from the outside of the carb. The other jet should unscrew just as readily: Size 78. I want to be able to check the orfice size with a gage pin to see if it's worn out. We carry the most common sizes for your Harley: sizes #. If the carburetor is too large, the pump shot will be con-sumed before the main system starts. This is the stock jetting for this CX500. Throttle Body and Main Venturi Sizing. Fuel Injector and Fuel Pump Calculator Brought to you by: East Coast Rolling Thunder car club This program will select from the following based on your input: Fuel Injector Sizes: 19, 24, 30, 36, 38, 42, 47, 55 & 120 Lbs. As to the jetting question. Idler jets start at #30 and increase in increments of 5 to #70 Note on the 582 and 503 DUAL carb Rotax engines we have found that a decrease in the idler jet size provides a smoother engine idle. If you find that the new jets didn't do the trick, you'll need to install some the next size bigger or smaller until you find that your engine is getting the right amount of fuel, which means taking out your carb, replacing the jets, reinstalling your carb and then testing it all over again. Remove the jets and insert a smaller/larger set based on the vehicles operating altitude. WEBER CARBS, Carburettors, Jets, Emulsion tubes, Conversion Kits, Air Filters, Linkages, Rebuild Kits, carbparts. Clymer manual says standard is 175/58. With your S&S, if I'm correct, your accel pump is adjustable. and it comes pretuned on the wet flow bench for your. also, i have always needed a bigger pilot when switching to headers, so i would say, if you have any header, go up 2 on the main, raise the needle up 1 position and go up 1 on the pilot. The taper also affects the main jet size your carburetor requires. as necessary. Check out this 2014 Ducati MONSTER 1200 S listing in Houston, TX 77037 on Cycletrader. When we tuned our Mikuni we tried about ten different main jets, five pilot jets and every clip position on the needle jet. The important thing to remember is to begin the tuning process with jet sizes that correspond to what your original plate system came with. These differences are very evident when the gaskets for the carburetors are switched (4350 gasket on the Q-jet carb on the left, and Q-jet gasket on the 4350 carb on the right): The difference in mounting holes, as well as the size and spacing of the throttle-bores, means that the carburetors will not interchange. Header Tube Length. I have a 650 Holley, the 650 was a low mileage carb that was run on a drag car, it has the nozzle type squirters and had larger jets in it. 055 is in inches, cuz i don't have any drill bits that say 0. RZR 900 and 1000cc plate Systems. Holley says its jets are sized by flow and not by orifice diameter so that's the reason for the disparity. As to the jetting question. 75 each Please inquire for the jet sizes you need for your carburetor application by email. S&S Carburetor Jetting Guide. Carb cleaners are an essential item when it comes to vehicle maintenance. Avoid using something larger than the jet holes as they are made of brass; meaning that they can easily become bigger which in turn would cause unforeseen problems. At SBT, we have quite a few PWC carburetor rebuild kits available. When the operating altitude of the engine will be 2000 feet higher than your normal altitude, you'll need to insert a jet one or two sizes smaller than the size currently installed in the carb, which reduces the amount of fuel entering the engine to match the reduced level of oxygen in the air. 5 years now. would be aprox aprox 176 jet. 35 each Pump jets $19. Engineering from the minds of racers, coupled with the latest in CAD and CNC technology, allows BBR to house one of the largest selections of innovative four-stroke MX performance parts in the world. Jet Needle. KTM SX50, Husqvarna TC50 Carb Parts: Pilot Jet. Carburetor sizes - 2 barrel. My Review: Big improvement over the worn out stock carb. Air correction jets? I believe it's built into the casting. Includes articles, videos, news, and forums for beginning to advanced anglers. When the carb is at tickover the needle is at the thick 0. MAX JET COMPONENTS 396 1. Repeat the process with the main jet adjustment screw, but turn it counterclockwise by 1 to 1-1/2 turns. By comparison, the size 75 jet has an area of 0. If you find that the new jets didn't do the trick, you'll need to install some the next size bigger or smaller until you find that your engine is getting the right amount of fuel, which means taking out your carb, replacing the jets, reinstalling your carb and then testing it all over again. Posted by Allan K on 27th Apr 2015 after having jetting difficulty's with the jet kit I purchases the OEM jets were sized in a understandable and progressive sizing so I could successfully re-jet my 2008 KLR. If you are using a 'wet' setup, you can calculate what the Fuel Jet size is by filling out the nitrous pressure and fuel pressure fields for a given Nitrous Jet. For Carbureted Triumph Bonneville Americas, Americas and Speedmasters (2002-2008/2009, depending on country). My question is how far should the sizes in jetting be between the primary and the secondary? I was using a holley street avenger 670 with vacum secondaries and the jetting was 70's in the front and 72's in the rear. A single throttle body EFI conversion kit, by comparison, will set you back $2,000 to $2,500, and a port EFI kit can cost upwards of $3,000 or more depending on the capabilities of the kit and what type of injectors. Carb Jet Cleaner Wire Set 665-9273 $14. through the jet when poured in the calibration direction from a height of 50 centimetres. The number is the metering area in thousands of an inch for a single jet/rod in the carb. Wondering how to choose a carburetor? This is a question that confronts anybody in the market for a carburetor, whether it's for a street or race vehicle. performance starts here! mikuni racing carburetors main jet tuning calculator. Jet Chart or Calculator If this is your first visit, be sure to check out the FAQ by clicking the link above. The carb's main jet affects how the carb works from half throttle to full throttle. This is a very small brass piece, so be sure you have a pan of some sort to catch it. Enter the engine's displacement, Volumetric Efficiency, and its redline. Installing jets of different sizes helps increase/decrease the fuel/air ration depending on what your bike requires. These particular power valves are located in the metering block of the carburetor (behind the jets) so changes are relatively simple and straight-forward. what size carb for 351w blow through??? It would come with all the needed power valve jets for future tuning. When you buy a used carburetor always check the jetting. Tuning Tips & Manual Downloads. The calculator will tell you the cfm range you need. Yamaha Motorcycle Carb Main Jets Carburetor main jets are susceptible to corrosion and pitting from fuel additives, and older fuel can cause a varnish build up that may not clean off completely. Builder: C. admk550: $5. 0 0 0 0 0 0 0 0 0 0 0 0 0. The idea is to convert currently-used Holley jet numbers to a "standard" environment, so that one can perform future calculations to other environments. Do one jet at a time, and put your old ones into the kit where the new one came from. The Nitrous Jet Calculator will help you calculate Horse Power ratings for jets used in nitrous oxide systems. It is only a guide. 95-J † 14 piece wire set with spiral knurling † Great for cleaning popular size jets and carburetor body holes † Set is approximately 3" long and each wire is about 2 1/4" in length Mikuni Main Jet Carrier Stores 22 main jets in a molded neoprene rubber carrier. The largest bass fishing site on the Web! The Ultimate Bass Fishing Resource Guide. This information to be loaded at a later date. If using with a DynoJet kit or various aftermarket jet holders (emulsion tube) the threads will not match. Do one jet at a time, and put your old ones into the kit where the new one came from. Too white, increase the jet size. Vonderhey: If you remove the stock airbox and filter and use an after-market exhaust, I would go up two sizes and work from there. and you can NOT guess what your change is if you change both the jet AND rod. In order to calculate your pump needs, you'll need to know two basic things: how much pressure will your setup will need, and how much Horsepower you plan on making. Shown below is a typical carburetor. One “size” on an air jet is “20”. The influence of the various carburetor components. Year 1988 Engine 883 – Jet Size 35 Year 1988 Engine 1200 – Jet Size 35 Year 1989-1991 Engine 883 – Jet Size 45 (California 42) Year 1989-1991 Engine 1200 – Jet Size 45 (California 42) Year 1992-1995 Engine 883 – Jet Size 40. Probably comes jetted square like that because it has a power valve on the secondary while other carbs with a jet size bias, do not. The Weber is. 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. The carburetor slide (or valve) has a cut-away and moves up and down within the bore of the carburetor to control the AIR flow through the carburetor venturi (see above). Re: blow through carb trouble! September 5th, 2014, 09:11 PM jeg's got me some more parts just in time today. to the ball game, etc Even with that mild cam, a 600 is the min. as necessary. Apparently the diameter of the mainjet can be determined as: d2=d1*(ad2/ad1)^0. When you get a new carb, you generally have to re-configure it. Jet's makes pizza, wings and salads using quality ingredients and has over 380 locations in 20 states. com----Misc. Remove the top access panel and adjust the carburetor in the following manner: Adjusting Low-Speed Needle. This being said, the CarbJetKit Jet Kit Calculator allows you to purchase a Jet Kit fit for your bike without the need to buy a kit that simply suplies multiple jets etc. SERIES PRIMARY SECONDARY THROTTLE BORE Booster Style Booster Size Prim Jet Sec Jet Idle Bleed Inter. This is usually the jet size in inches. 3-Cyl SXS EFI Systems. Carburetor Specifications Carburetor Schematic 0739-211 ITEM Type Mikuni BSR36 Main Jet 130 Pilot Jet 22. Step 4: The main jet’s passage is where fuel flows through the carburetor into the combustion chambers. Rochester Quadrajet Common Problems and Decoding. Please remember that sometimes the stock OEM jetting will work just fine, other times you may have to make an adjustment, so use our suggestions below as a guide to help with your jetting problem. As a good estimate, use the formula below. as necessary. If the adjustable jet is to the front of the carburetor, on the side or bottom, it. is regulated by the main. Mikuni Main Jets. 1971-1972 Ford Mustang Autolite 4BBL Carburetor *RemanufacturedOur Part No. Moped carburetors come in different sizes from 7mm to 14mm venturis, and from #39 to #68 main jets. First of all, carburetors need no intervention of ECU's which can be both expensive and in most cases limited in adjustability, unless expensive alternatives like those programmable variety is in your budget. 67 Mercury Park lane 410 FE What size jets on autolite 4100 - 332-428 Ford FE Engine Forum. It is tempting to use the largest size for the most airflow, but this can hurt performance. Calculating jetting for Aquamist systems is quite easy as we will walk you through a few simple steps, then some examples. Vacuum Secondaries. You just remove the top lid of the carb and the jets are right there. Holley says its jets are sized by flow and not by orifice diameter so that's the reason for the disparity. This will, provide you a baseline as to how your carb started out. With your S&S, if I'm correct, your accel pump is adjustable. The calculator will tell you the cfm range you need. Hardgrove warns there's more to consider than just cfm values. This of course assumes that you are starting out with the stock jet size. The venturi sizes listed below are the sizes supplied by Weber in new carburetors. You can change the jets with the carb on the car, it's one of the best features of the Edelbrock carb. A one-size larger pilot jet will have nearly the same effect as a one-size smaller pilot air jet. A WORD ABOUT JETS: • ZEX™, Nitrous Express™, Nitrous Works™, and Compucar™ all use jets that are dimensionally very. is regulated by the main. We measured 10 new Holley jets of that size and found diameters ranged from 0. Our one Ultra-series carb was the 950. We have been in the carburetor since the 1940s and we have an. As you can plainly see, the size divisions for the smaller jet sizes produce a more dramatic change than for the larger jet sizes. In order to calculate your pump needs, you'll need to know two basic things: how much pressure will your setup will need, and how much Horsepower you plan on making. We ship internationally the same or next business day and support supply to thousands of restorers and workshops. P200 Day-to-day and Rally bike 'One Careful Owner'. The fuel is forced from the jet to the nozzle extending into the venturi. Our one Ultra-series carb was the 950. 5 I believe. Unbelievable shopping deals in every category. it has been a great tool for identifying what jet size the bike needs, then fine tune the carb and let. Question I have is how does the carb size affects the power?. Check out this 2014 Ducati MONSTER 1200 S listing in Houston, TX 77037 on Cycletrader. Mikuni HSR42 Carburetor for American V-Twins. The selection of main gas and air correction jets is determined by venturi size. 4572mm which is about a 46 pilot. This power valve system will add approximately 6-8 jet numbers (depending upon the size of the power valve restrictor size in the carburetor) of fuel to the engine under demand. Drilling jets and carbs are quite simple if you go in step sizes with a hand pin vise. The difference was significant. and avoiding constant changes to your jetting as all other jet kits require you to do. I personally try to not use a home drilled Fuel Jet in a carb when I can use a factory jet. Picking the right Carburetor size for your car & engine combination is paramount in being successful - whether you're a professional racer or just want the right carburetor for you're Saturday night special. i would go 2. A good starting point is 5-6 jet sizes bigger than the primaries, but each combo is very different, so actually test it, that's just a baseline! (I've seen some the same size as the primaries, and some 12-14 sizes bigger!). However, if you have a new more. This Jet Size Calculator will give you the size of the jet you need for a different weather condition. The stock main jet in the 40 hp carbs is a 47d. Holley Carbs for example,,,I cant recall Exactly how they determine the Number stamped on the jet,,, But they Drill a buncha jets during a production run. Now, having found the correct main jet repeat this process for the needle clip position, again recording the settings and air temperature as above. Holley says its jets are sized by flow and not by orifice diameter so that's the reason for the disparity. Keihin Jet Identification Chart. Disassemble and check your carburetor(s) to verify the recommended jetting listed in the recommended Bing jetting chart is installed in your Carb(s). I've been through Holley's web site and have also spent the past hour surfing through various search engine results to no avail. For this process to be almost perfect the system needs to take into account, power setting, mixture control and such. Have had the Toy carb on my DD for 3. All OEM Mikuni jets from the Japanese factory are flow rated and every individual Mikuni Jet size item is absolutely identical. There are 3 main parameters that correctly determine your baseline selection. Below is a chart showing approximate idle jet sizes for given engine sizes, this assumes one carb barrel per inlet port E. Rochester Quadrajet Jets All sizes $6. Ford and Mustang Intake manifold. 0 0 0 0 0 0 0 0 0 0 0 0 0. Can Am Plate Systems. Find whats available (maybe a chart), jet size wise, for your carb. Main Jet 400 2003 Pilot Jet 40 Needle 38-70 Clip Position 1ST Air Screw 1. By 1973, all automotive 2G`s used the large flange. Main Jets Please select your jets carefully as these are a not returnable item due to the possibility of undetectable customer tampering posing a catastrophic risk of warehouse stock contamination. it has been a great tool for identifying what jet size the bike needs, then fine tune the carb and let. If you had an air density gauge, you could easily calculate the jet size for your area. 0853 FAX 901. Use under medical supervision. You most likely will have to change the jets (as I did) from the stock 1406 jets to the 1405 jets and metering rods. 90-175 (Δ 2/3) Nickel Plated 175-200 (Δ 5) For watercraft N424-52-SIZE 6mm Slot head Powerjet for OEM PWK carburetor,. started Bo Laws Automotive focusing on high performance service and engine building. 41mm is very close to the size 42 jet, the difference is due to the fact that the jets are drilled in mm and the bits are sized in inches. If this is the case, then you should consider changing venturi sizes or go to larger/smaller carbs! Jet Sizes: One “size” change on an idle or main jet is “5”. When deciding upon an appropriate throttle bore diameter for your carburetors it is easy to err by over-sizing them in the belief that a larger bore size will deliver more power. This is not going to be an over carburetion situation. Carburetor Road Demon Carburetor Road Demon Carburetor; 625 cfm; Vacuum Secondary; FEATURES: Max-Density Cast Rib-Reinforced Baseplate Max-Density Cast Metering Blocks Four Corner Idle Circuitry Large Capacity Float Bowls Large Glass Float Level Sight Windows Integral Hi-Flow Choke Housing Dual Feed Inlets Vacuum Secondary Operation Power Valve. The technique for establishing the correct idle jet size is detailed later, but as a starting point 40/45f9 idle jets for a 1600 engine 45/50 f9 for an 1800 and 50/55f9 for a 2000 will get you out of jail free. Lectron is celebrating 45 years of helping riders get the most from their vehicles with our high performance carburetors and EFI. Whether you need a motorcycle carb cleaner, a carb cleaner spray or a simple small engine carburetor cleaner, we’ve developed a list of the top products on the market that available for you to buy at the best prices. (Thats the only difference) Does anyone know the sizes (#drill or inches) of these nozzles, or just the correct size of a 719 nozzle? I'm in the (or going in) the "Owner Maintenance". I just aquired a Barry Grant Speed Demon carb that is a 750 in size with vacum secondaries. Carburetor Float Replaces Briggs & Stratton 398187 Part #: 22-10053. It has sizes designed for most small motors. Does a chart exist, that crosses jet sizing. You know, just a ride to get grocery goods, church on Sunday, a drive on the Hwy. 1 Kit per carb is required Look carefully at the diagram that comes with your carburetor kit - the kits will differ depending on what kind of carburetor you are rebuilding. Drill bits sizes that approximate mikuni jet sizes. 016 etc} I have some cb750k 1978 carbs ,that the slo jets , are too far gone{press type} and I would like to make replacements for them. There's also a good web site with a jet size calculator on it for a wet setup (where you're metering the fuel and nitrous yourself). Motorcraft 2150 2V Carburetor. geared people moved car. RZR 800cc plate Systems. When deciding upon an appropriate throttle bore diameter for your carburetors it is easy to err by over-sizing them in the belief that a larger bore size will deliver more power. Carburetor troubleshooting is simple once the basic principles are known. Yes those were 4V heads but, it was the factory's choice back in the day. The kits using the 32/36 progressive carburetor is the optimum carburetor for use as a replacement carburetor for a worn out or hard to maintain factory carb. Go buy jets 3 or 4 sizes smaller and you should be fine. Variations such as bore size, automatic or manual choke, and the size of the accelerator pump used was identified by these two letters. Manufacturers develop their jet charts with these components in mind. "Car" carb jets and the old Fuel Injection "Pills" are usually calibrated in numerical sizes according to Orifice Diameter. Dating Your Carburetor. when i bought my lite ace 1995 GXL model, the stock size carb jets in place were 130 and 160, i suppose this is 1. Top End Performance has been your source for the best prices on brand name, top quality car parts since 1994. RZR 800cc plate Systems. Holley Jet kits are fairly cheap, same deal for the Comp stuff in the overall Boosting game. Our one Ultra-series carb was the 950. Shop with confidence. A one-size larger pilot jet will have nearly the same effect as a one-size smaller pilot air jet. Consequently, if the jetting was on the money before the spacer was installed, the carb may need to have a size or two larger main jet to compensate. There are 3 main parameters that correctly determine your baseline selection. I'll try to get pictures and details ASAP. The online description does not say what size jets are included. Keep in mind that these specifications were written when gasoline was much different than it …. Since it is less efficient you engine will likely run leaner and you will likely have to enrich the mixture by going up one or two main jet sizes. 00 condition of jet sizes on the chart. As to the jetting question. N424-35-SIZE 7mm Length Nickel plated slow jets to prevent corrosion. I don't remember, it's been a number of years since I had a carb on it. The pictures below show where to find the carburetor number and the types of linkage hook-ups. A # 100 jet is 1. Run the engine with the stock main jet and take a plug reading. In 1965 Bo Laws, President of BLP Products, Inc. Order by selecting the jet size from the drop down list. The influence of the various carburetor components. of Reducers: Reducer Outlet Size (in) Misc. Aircraft Engine Carburetor. Buy Mikuni Carburetor Jet Pocket Tuner Sliding Calculator: Accessories - Amazon. Dinqua's Jetting Calculator. 11-07-02 10:08 PM - Post# 134513 Need some help, guys I'm looking for a listing of Holley jet sizes and corresponding drill sizes. , so I cant tell you what the next step smaller (lean) than 1. DOWNLOAD 440 artic cat snowmobile carb jetting chart - Back to all "Snowmobiles". The technique for establishing the correct idle jet size is detailed later, but as a starting point 40/45f9 idle jets for a 1600 engine 45/50 f9 for an 1800 and 50/55f9 for a 2000 will get you out of jail free. The perfect way of jetting a Holley How many of you guys determine your jet sizes by reading the plugs at WOT? According to the motor Bible(Dennis Moores BBC Marine Book), you are supposed to jet you carb at CRUISE, at which point you have 100% flow thru the jets. For example, if you want to run leaner , go from 80 rear jets to 78s. car weight 2433lbs. You can also solder the ends closed and redrill them smaller if you are so inclined. 38 mm in diameter. One column for fuel jet size with the fuel pump that comes in the kits and the other column for hi-output pumps – like the Holley Blue with 5-7 psi flowing pressure. Hi,I log on to your blogs named "How To Quickly Determine The (Dell'Orto) Carburetor Main Jet Size - TuningMatters. We also cover vacuum and mechanical secondaries. The first step is to find where the engine is running poorly, fig 7. When we tuned our Mikuni we tried about ten different main jets, five pilot jets and every clip position on the needle jet. The online description does not say what size jets are included. As the needle gets thinner towards the bottom pointed tip , more fuel is allowed in. The main jet. Step 4: The main jet’s passage is where fuel flows through the carburetor into the combustion chambers. Make sure your plugs burn a gray color. If using with a DynoJet kit or various aftermarket jet holders (emulsion tube) the threads will not match. You also need a calculator to establish, from the readings taken, what the density altitude is. It was a "107", which means the diameter of the hole in it was 1. •Always use an insulator block between carb and manifold. Take the carby top off. It will give you jet. com and affiliated sites. Those sizes range from #82. 016 etc} I have some cb750k 1978 carbs ,that the slo jets , are too far gone{press type} and I would like to make replacements for them. Similarly, a change in the carb's inlet air temperature may require a change in the jet size from the stock calibration. 6) Intake valve size is the diameter at the bottom of the valve and is measured in inches. Does a chart exist, that crosses jet sizing. Increasing a nitrous jet size will make the system run more lean, increasing the fuel jet size will make the system run more rich. Correct fuel jet size for this carb is 0. What you need is a blend of power and drivability. Allstate Carburetor is providing the Holley Double Pumper 4150 Specs. The Main Jet is the #1 thing that people change in a carburetor when it comes to tuning them. We have any orifice size from 50-109 to choose from. The Mikuni substantially increases power compared to the stock carburetor. 0 0 0 0 0 0 0 0 0 0 0 0 0. Conventional Spraybar Jetting (one nitrous and one fuel bar) Gemini Spraybar Jetting (two nitrous and two fuel bars) NX Nozzle Systems with 15005P Fuel Pump. Because of the lousy gasoline we now have, do not use printed jet sizes as a definitive answer. All of the parts listed below are available on our website. I also got spare o-rings for the idles and put them inside as well. If the carb is too big for the prop/engine combination, it will not tune up properly and be erratic and un-reliable. The standard tuning seldom needs more than small adjustments to accommodate a wide range of engine set-ups. Install a main jet that is two sizes richer (the number on the jet will be higher on a richer jet). A leaner needle taper will use a richer main jet than a comparable engine/carburetor combo with a richer needle taper. Use the following calculation. 30mm, so i am confused as to to what the actual siz e of the drill bits are in standard. Once you had the mixture dialed in, using air temperature and barometric pressure, you could calculate the air density and jet sizes you needed for a particular set of conditions and be close if not spot on. This jet doesn't really even look like a jet, but it is! It controls the fuel mixture from 15% to 60% open throttle. As the needle gets thinner towards the bottom pointed tip , more fuel is allowed in. I wondered just how small my main jet was so I took my carburetor apart and removed the main jet. Holley jets range in size from 40 to 99, with the stock jet size differing based on the carburetor model and engine application. Such a list would be too big on our website, so we are going to list the most popular Holley four barrel carb List #'s and their cfm size and stock jetting specifications. If you have questions about our products, need a part recommendation, or just cant seem to find what you need you can contact our Tech Support online and receive answers by e-mail. The first step is to find where the engine is running poorly, fig 7. Tuning Tips & Manual Downloads. Required Intake CFM This calculator will help you determine your engine's intake volume requirements. Once the 4 screws are removed the main jet and slow (or pilot) jet can be removed. Don't throw out the old exhaust. The Main Jet is the #1 thing that people change in a carburetor when it comes to tuning them. 100 inch or more. 5 HP 196cc engines. Holley Carburetor Main Jets are made of brass and have a 1/4"-32 Unified Fine Thread. To order Jets please click here. V-Belt Length Calculator. I need to know wat 0. so if the rough jet sizing for a gas carb is say 80 jet so would it be correct to say than when using methonol carb. Carburetor Rebuild Kit Selector. Enter the designation of displacement, 1 for cubic inches or 2 for cubic centimeters. 03937 = 1 mm) I have never known anyone that has been able to get any more out of a 1300 with a jet over 225 in size. ) However, in search of more power, does changing to a bigger size carb would "release more power" ??? I was told a 34/35mm size carb would release more power. The online description does not say what size jets are included. put a 255 BBK pump in the tank, slapped in a new aluminum radiator, welded a section of the intake tube together to reduce couplers to blow off, swapped the spring in the BOV again since I cut too much off the last one. We are adding more Motorcycles constantly! Using the CarbJetKits Jet Kit calculator is the only way to reach optimal performance. If you find that the new jets didn’t do the trick, you’ll need to install some the next size bigger or smaller until you find that your engine is getting the right amount of fuel, which means taking out your carb, replacing the jets, reinstalling your carb and then testing it all over again. This is often a big mistake, as it only controls 3/4 - WOT, and NOTHING ELSE. HONDA CR125 JETTING RECOMMENDATIONS Here are our jetting suggestions for your CR125. Only a thousand miles past a thorough rotisserie rotation that's brought it to a stellar condition, this 1969 Ford Mustang Mach I 428 Cobra Jet is powered by o.