Mercury Outboard Idle Mixture Adjustment - Having a bit of difficulty getting mixture.

Watch the linkage on the side of the powerhead whild somebody operates the throttle control. Idle mixture screws on those carbs starting point is 1 and 1/2 turns OUT from 'lightly seated'. It idles around 700-800 when in neutral, but when I pop it in gear it drops to 400-500, bouncing around and stalls. As long as the fuel system is funtioning correctly, you can vary that by several degrees and you'll know by the rpm's at idle in gear when you have it right. Oct 19, 2020 · It's the OMC Johnson Outboard service manual. Firstyou cannot adjust these on a hose, need to be in a barrel or backed into the water. Learning how to set air mixture screws on Edelbrock carbs will give you the ability to adjust the. 5-turns out and adjusting it any doesn’t seem to help. It simplifies boat operation while improving engine performance and decreasing fuel costs. Once in forward, it is impossible to shift back into neutral. Turn the idle mixture screws in and out until the vacuum is the highest. Chrome: Even beyond ads, some websites are so cluttered with autoplay videos, sidebars, and other distractions, they make it hard to actually stick to the one thing you came to rea. You don't have to worry about timing at idle if you set it at WOT while Cranking. I don't have a manual for the motor and I'm not exactly …. You Save: 0% off MSRP! NOTE: This Item is a Non-Stocked, Special Order, OEM Mercury Part. Learn about the 1964 Mercury Comet Cyclone. This can restrict fuel flow and cause a rough idle. Carbs initial setting is 1-1/2 turns open. Insert the screwdriver into the valve screw and turn it in 1/8-turn increments to the right until the motor idles evenly and smooth. The seller assured that this was because the engine was being started for the first time since coming out of winter storage. Could be a little thing like a slight turn of a screw. Remove the spark plugs, and ground out the leads. Will not start unless I use the priming bulb. However, there's one more thing you can do to troubleshoot an outboard that runs poorly at idle: Clean the Carburetor. Make sure when you adjust them that the thermal valve hose is disconnected as if hooked up and engine not at temp the adjustments will be off. i have adjusted all three carbs 1 and 1/4 turn out. You should replace all the fuel hoses and filters if you think they are origional. #1 came from a Seloc manual for my motor, #2 came from an on-line Mercury manual for the same motor. Now put timing mark on #1 plug wire. My seloc manual says initial pickup timing: align marks (on bracket and cover) and adjust throttle lever to just barely touch cam. Joined Aug 21, 2001 Messages You need to warm it up and adjust the idle mixture screws with it in gear and in the water (not on the hose). the idle adjustment is at the. 5 billion) project will take seven years to enter in an orbit around the closest planet to the sun, where it will begin to unravel the mysteries of Mercury. utica observer dispatch obits today -----At idle there should be about 1/4 ' or 6 mm gap. 2 stoke outboards do not use any type of sync gauge. Lubricate drive pin with 2-4-C w/Teflon Marine Lubricant and place into flat of shaft as shown. The 2-cycle outboard carburetor has two adjustment knobs (a large stop screw knob on the left side of the motor and a carburetor idle. Shoot the red dot on the metal shell of the plugs and diddle the idle mixture. Spring, Idle Speed Screw Cleaning Cleaning must be done with carburetor disassembled. Rough Idle--2002 90 ELPTO it says to set to 1-1/4 out for all three. nashwinter123 Petty Officer 3rd Class. To adjust it, start by turning the screw in 1/8 turn increments. ) I have seen many, many, posts from all kinds of folk suffering the same kind of problem on all makes and sizes of outboard engines. That idle mixture screw needs to be screwed out just a bit from where it was set from the factory to get a good dependable low idle. Checking sync and link settings on 150hp carbed V6? Could you tell me where the idle mixture screws are on Mercury V6 carbs? J. The idle mixture screw on a 2006 Mercury 9. Take turns with each idle mixture screw. pressure cleaning jobs Brendan, You'll do best to run at a 50:1 mixture. I have a 2004 Yamaha F60 (F60TLRC). I'll show you how I adjusted the idle on my Mercury Blackmax 135. Keep in mind that if you set the idle in a tank, it will be slightly lower when in forward gear. amazon cheshire cat costume Check again, if it still bogs a bit, turn another 1/8 CCW and you should have it. The adjustment of this screw plays an effective role in increasing or decreasing the idle speed and supporting the engine running smoothly, preventing high RPM when starting the car. Initial setting spelled out in the manual calls for 1 and a half turns out from 'lightly' seated. Reeves) Initial setting is: Slow speed = seat gently, then open 1-1/2 turns. Since I've fixed my bowl from running over …. Re: carb mixture screws dont do anything! i'll adjust the neutral idle then see if that works. Two-stroke 15-horsepower Mercury outboard motors require a 50:1 fuel-to-oil mixture. Re: 150 Black Max idle too highhow to adjust? The idle is set by adjusting the intial timing. Insert a screwdriver into the Mercury’s idle adjustment screw, located at the bottom of the carburetor, and turn it to the left until the motor barely continues to run. I was goint to start turning the screw in until. Adjusting both of these requires that you have the motor running. WME carb air correction screw adjustment thanks, I adjusted the idle screws to 1 …. Re: WME carb air correction screw adjustment. If it has sat up for a few years your carbs are gummed up and a carb cleaning is in order. Trimming the outboard adjusts the boat’s attitude, or the angle of its bow into the water, which can help dial in the best ride by compensating for vessel load and sea conditions. 2 - the idle is the big flat head screw and nut at the bottom of the tower (it will not mess up timing) - set it to about 1100 rpm in the driveway after warm. Re: merControl throttle and idle lever CABLE Adjustment. As a newer 4-stroke outboard, it's designed to run at many various altitudes and temperatures right from the factory without adjustment. And luckily, this blog will share a descriptive chart of Mercury 2 and 4-stroke spark plugs. I have read all the rough idle posts and still have a question. Many of the older 2-stroke outboards, like the 78 Johnson mentioned in the original post, are more sensitive to altitude and temperature changes. lanikai lane mobile home park A carburetor cleaning or a complete rebuild might be necessary. However the tag on the support cover says idle timing should be 5*-7* AFTER TDC. On the carburator you will notice where the mixture adjust screw goes into the carb. This video shows a simple way to check your outboard carburetor l. (the Clymer Manual calls them "idle mixture screw" & "idle speed screw" ) to get the idle set ~600-700 rpms. The Rochester 4 MV had an electric controlled meter valve that adjusted with the same dwellmeter that is used to adjust ignition points. Idle mixture should be set while idling IN THE WATER in forward gear, adjust to best idle speed using only the mixture screws then open each an additional 1/8 turn. Turn in pilot screw until it is lightly seated. 4 You can do this by ear,vacuum gauge or with a tach. Idle speed with the motor out of the water on muffs should be around 900 - 1000 RPMs. Repeat on the other 5 cylinders. This past fall, during winterizing, the engine was 'sneezing' ever so slightly. Re: 25 hp mercury bigfoot vibrates and shakes at idle. Those engines were prone to fouling plugs from overly rich conditions. 25 turns open and the idle got smooth and the flat. mary beth o'banion 1) Fuel Filter - I cleaned the fuel filter by unscrewing it and blowing out the bits of dirt in the container and on the filter. Read our Mercury Business Checking Review to learn more. Re: IDLE MIXTURE ADJUSTMENT ON THE STROMBERG 175 CD-2. It runs great-good take-off power and good top end. When you get it in the water try throttling up, if it boggs then open the screw 1/8 turns and retry throttling up. , it opens the throttle a little more). Reeves) The adjustment procedure of the carburetor slow speed needle valves follows. Thread starter tinlid; Start date Jul 22, 2008; T. Joined Apr 5, 2009 Messages 82 Idle adjustment 25 hp evinrude 89' There is a idle fuel/air adjustment screw on the carb. Loosen the nut and turn the screw in or out as needed. I have a 1994 25 hp, 2 hole 2 stroke Yamaha and I’m having trouble with the idle air mixture. Thread starter Test acceleration, ANY hesitation, even the slightest, indicates a need for more idle mixture, make small adjustment, repeat testing to perfection. Thread starter dog22; Start date Jun 26, 2023; D The procedure is to adjust both idle mixture screws for best idle. 30hp 2 stroke Carb/idle questions. I have a 1999 Mercury 150 XR6 carburated outboard. Outboard Motor Automobile Engine Marine Equipment Motherboard. Throttle in neutral, and no high idle. Re: 1988 Force 125 Idle Mixture Adjustment. The control has an outside lever for the throttle/shift and an inside lever for idle/throttle control. Adjust the Ignition Timing Detach the throttle cable from the power head and attach a timing light to the top spark club lead. ; Adjust the idle speed: Before adjusting the fuel mixture, it’s important to set the idle …. Here are the symptoms of tight power valves: stop producing power. (Dual Carb V/4 With 4 (2 each carb) Slow Speed Adjustable N/Valves) (J. 5 turns out then adjusted in for the fastest. The engine should have a smooth, steady idle with the screw between 1/4 and 3-1/2 turns out from fully bottomed (gently!). Jul 11, 2016 · It states: "Idle mixture screw adjustment is required when carburetor has been overhauled". Then, slowly turn the screw counterclockwise until the engine runs smoothly. Our new 2021 Mercury was having idle issues such as high rpm at idle and irregular idle speed. To do that you adjust one needle at a time for best, smoothest idle. I thought the Mercury 50 2-stroke had been in production long enough that any manual would have the same procedure for this basic service item, but I. Tighten locknut (NO TAG) and turn. Outboard 1965 - 19891965-1989 Mercury Outboard Idle Mixture Adjustment. I adjusted the idle screw clockwise about a 1/8-1/4 turn. Then below that it states: "The idle mixture screw is NON-ADJUSTABLE - 1998 and later model years. It’s highly recommended to follow the idle mixture adjustment procedures in …. You are only concerned about the lower screw at idle. Carbs leaking oil and gas mixture. You back the needle out until you hear the miss in it. I ran the engine for 3 hours the other day with brand new plugs using a 50:1 ratio. NEVER attempt to set timing while under way. 1 64 scale 2nd gen dodge Don't forget to ground all 4 plug wires. Procedures are applicable to the following models: MERCURY OUTBOARDS. - Adjust the idle mixture screw (either direction) to achieve the smoothest, highest RPM. cindy lou blow up Power tilt and trim, available for 25 and 30hp FourStroke outboards, lets you adjust the running attitude with the push of a button. Idle mixture screw for 1999 Mercury 150 xr6. Once you have that on both carbs, check your hole shot and if it bogs, turn each needle about 1/8 turn CCW. Be sure the throttle plates are closed so the idle circuits are working. My problem is that the throttle shift lever goes well beyond the 90 degree position to get to full throttle. 0 merc tks idle/stalling issues. I just finished the rebuild on all six carbs on a 175 hp evinrude. Turn idle screw COUNTERCLOCKWISE until engine fires unevenly (over-rich mixture) Slowly, turn idle screw CLOCKWISE until engine fires evenly (and RPMs increase) Continue to turn idle screw until RPMs fall off and engine misfires. Most seem to be dirty or clogged carbs. I looked at his shop and it was obvious he was a very experience gear-head so I. Mercury's 250XXL Outboard - Steering: Remote Mechanical, Starter: Electric, Shaft: 30" XX-Long, Weight: 548lbs, Power Trim & Tilt. Set the idle speed stop screw on the throttle linkage to match the throttle position. #17: FO9678: CLIP-CHOKE SHAFT (1 required per assembly) FO9678 - CLIP,NLA [ More info] Unavailable. 2) Pilot Screw - Then I removed the pilot screw, cleaned it off, sprayed carb cleaner into the hole and replaced it. Shut off the motor, and place the cover back over the 2-cycle outboard motor. You can adjust the idle there. To adjust the idle speed on a Johnson 40 hp outboard engine, first locate the idle mixture screw on the carburetor. Lightly seated 1-1/2 turns out 3. Thread starter DirtinLa; Start date May 19, 2016; D. What do you check when your outboard idles and then dies? In this short video from Boats. Many are now asking, what will carriers do with. Recreational Outboards - Make every minute count. Every spot, every tow, every cast. I have it at the old standard 1 1/2 turns out, but I have no idea. Alternatively, If you set it at some. dragon ball wax (Carbureted, 3 Cylinder, 2 Stroke) The symptom is exactly as you see/hear in this YouTube video (You will also note you tach behaving erratically or, dying. Advertisement Depending on your purposes, there. You should start with it open 1 1/2 turns off lightly …. Turn it in (lean) until it starts to stumble, then back it out (rich) until it. When a boat is at idle, trim the outboard. Loosen 3 carburetor synchronization screws (a) to allow shutter plates to close completely. The 75HP is rated to 5250 rpm and the 90HP is 5500 rpm, the larger carbs are the reason for the higher rpm rating. Re: Idle Adjustment 1993 Evinrude 50 Hsp. I think it needs to be hooked up to a computer to be done right. Mercury/Johnson/Evinrude - Finding the sweet spot on Boat motor idle. MRCY: Get the latest Mercury Systems stock price and detailed information including MRCY news, historical charts and realtime prices. Filling Remote Oil Tank (If Equipped) Remove fill …. I have had it for 2 years and the first thing I did when I got it was clean the carb. Mercury SeaPro™ outboards are built to handle the heavy-duty needs of commercial boating applications. The upper screw is only the WOT stop for the carbs. These instructions are based on factory idle adjustment procedures. Mixture screw usually start 1&1/2 turns out. I have the Yamaha service manual along with the supplementary manual (basically F50 manual + differences for the F60). 100:1 will make scrap out of it in a hurry. but its hopefully there Or turn to page 102 which give a bit of detail on setting the idle mixture. rooms to go mattress sale queen Jul 22, 2008 If your engine just needs the routine idle adjustment, then the procedure on page 51 would probably do the trick?" Reply. apex kill leaderboard How to adjust Yamaha 40hp idle refers to the process of altering or modifying the outboard motor's carburetor so that it causes the 40 horsepower boat engine. and the floats are parallel to the carb. The pilot screws are for your low speed mixture and have nothing to do with. go carts spokane Re: Idle adjustment Johnson 150. 2005 200hp Mercury carbuerator problem. Hello, I have a 1995 Mercury 15 hp 2 stroke outboard. 2005 Mercury 90 hp ELPTO Salt Water. 1965 1989 Mercury Mariner Outboard Motors 45 115 Hp 3 4 Cyl 2 Stroke Service Repair Manual The Best Manual For Diy 1 It’s highly recommended to follow the idle mixture adjustment procedures in the factory repair manual. Refer to the download repair manual for idle rpm specifications. My engine is running a little rough at idle and smokes. If you havn't already opened it up, nows the time. In addition, troubleshooting fuel supply problems before makin. How to adjust idle screws on Mercury 75, 90, 100, 115 and 125 horsepower outboard motors. Choose the DTS Difference Buttons for activating and adjusting Active Trim are located directly on the DTS control, providing easy access to this popular technology. 1 1/4 to 1 1/2 out from lightly seated will get you close to where you need to be. Idle mixture is intended to be adjustable. The boat should be free and idling in gear to set the idle. Initial setting should be one turn out from lightly seated. idle adjustment mercury outboard 90hp. If the motor doesn't perform well, start opening it a bit until you get decent performance. Service manual (at least the one I'm looking at) is a little convoluted on this matter. jrampey Petty Officer 2nd Class. If you need richen the idle mixture-set the idle mix to 1. Start by locating the idle mixture screws on the carburetor …. 9 Outboard 4 stroke carb adjustment, 2012 model year …. to/3fb8dfnYou can also donate directly to my PayPal:https:/. After having the carb cleaned on our Mariner 15 2 stroke (1997), the motor has less power then before. Best rule of thumb is “clockwise until lightly seated, then back it out about 1-1/4 to 2 turns”…. Use the right tools: To properly adjust the fuel mixture, you'll need a screwdriver that fits the adjustment screw on your carburetor. If the fuel pump is on the left side of the body then there is an idle mixture screw. Turn the screw using a slot screwdriver until the engine reaches a smooth idle, where it is neither sputtering as a result of a lean fuel/air mix or has a strong smell of fuel from the engine running rich. Turn the idle mixture in or out 1/4 turn until the vacuum needle is steady and you get the maximum idle. With engine running at idle speed in “Forward” gear --turn idle mixture screw IN (clockwise) until engine starts to “bog” down and misfire. After a few stalling cycles the motor. Then start to turn it out slowly 1/8th of a turn at a time until the rpms drops again. I removed the cowling yesterday and discovered the spark advance rod was disconnected from the long actuator arm. It has been making oil for some time and this oil change smelled of gas. It will be located on one of the throttle levers (likely the inside lever) on the port side of the motor. Then wait for it to warm up and adjust until you get the best idleIt dont seem to change much do any of you pros have a didfferent way to adjust the idle screw jet. When it comes to fine-tuning the performance of your 2-stroke carburetor, the needle screw plays a crucial role. give it time to burn off fuel then turn another 1/8 When you have a good solid thrust under the gun then it is at it,s best setting. 8 HP) dies when shifting or idling down. Learn about mercury in CFLs and fish and find out which should cause more concern. *Stock Laser Injected Mercury motors use a TPS value up to about 3000 RPM, so may be less affected, depending on severity of the problem. 40 outboard motor pdf manual download. penelec erie pa outage I believe Matt is refering to the idle SPEED screw in his post, ""There is a spring that surrounds the threads of the screw. Proper idle speed and adjusting idle on 1998 Mercury Force 120 HP Your picture is small, but no those are not the idle screws - those are for fuel mixture - if you changed them set them to 1 1/4 turns out from lightly seated. Make sure they are steady and even. When to adjust the idle mixture on a boat motor? IDLE MIXTURE ADJUSTMENT. On these little tohatsu's, the pilot screw (also known as the idle mixture screw) is fixed and not adjustable. A good starting point is to seat the screws, then back them out 1 1/2 turns. Any carbed engine needs throttle added to start;that is normal. -----Then again it could be as simple as opening the lowspeed mixture needle 1/8 turn each. I havent been fishing much, but always top off the fuel or just run around to keep gas fresh in it also add marine stabil. 45 hp 4 cylinder 1965-1968; 50 hp 3 cylinder 1986-1989; 500/50 hp 4 cylinder 1965-1985. You need to adjust the idle stop screw. The problem is I do not know which screw of the two (one. While the adjustments seem minor, both affect the. Seems there's not enough travel in the screw adjustment. As you turn the valve in, the rpms will increase. I then covered the intake manifold port with my finger, the motor dropped down to 1000 rpm. If the engine requires more than three turns out, the pilot or pilot air jet may be too lean. It is running good upon initial startup and …. idle mixture adjustment after carb cleaning 90 …. 1996 40hp mercury outboard idle adjustment; 1998 mercury 40hp 3 cylinder driveshaft removal; 2 cycle 40hp 1993 yamaha outboard motor oil mixture chart; 2004 yamaha 40hp carburator adjustment; 2006 mercury 40hp outboard repair manual; 40hp 2000 mercury outboard oil injection sensor; adjusting carburetor on 1994 40hp …. If you are at sea level up to about 3500 feet, the factory jet will usually suffice. (14 mm) Main Jet Model 40 (WME-53, …. Joined Aug 1, 2016 (LHS in first pic, foreground in second pic) is the idle mixture adjust. Manual includes 15HP Sea Pro & Marathon motor models. dent on top of head if you disconect a oil injector from a mariner 1997 90hp outboard what would you mix oil to gas ratio at. Set idle needles open 1-1/2 turn from lightly seated. The tuneup specs say the 60 hp should have an idle speed (in gear) of 750-850 rpm, and the 70 HP 3 cylinder 1990-1997 models idle at 600-700 rpm and the 1998 to 2001 models idle at 750-850 rpm. When battery voltage is reduced, the engine will automatically increase idle rpm to boost alternator output and recharge low batteries to the proper level. then run the motor until it runs all the gas out of the carb. For a Mercury two-stroke model, 2- to 20-horsepower outboard motor manufactured before 1980, use a blend of unleaded gasoline with a posted octane minimum of 91 and Mercury or Quic. may vary some from motor to motor, according to the specs. Wait a few seconds for the engine to respond. rhode island apartments for rent craigslist the idle increased along with a shift problem It has a hot foot gas pedal installed. KEY FEATURES Go Farther: Advanced Range Optimization by Mercury Marine uses closed-loop fuel control to precisely adjust the fuel mixture and deliver the best possible. Work carefully and slowly to achieve the best results. Smokes quite a bit after idling for 10 - 15 min, like if im trolling. Rough idle is a subjective statement. Don't tuck it all of the way under. Shoot some carb cleaner down through this hole and see if that repairs the problem. Restricted low speed orifices in carbs,Link and synch out of adjustment. Use the base carb (#4) to set initial rpm around 900 and then going down from 1,2,3 you want to adjust the adjusting screw (not the mixture screw) to attain the least amount of vacuum difference in each cylinder. I understand the idling adjustment knob is a mixture control, but can see any idling speed adjustment. OEM Quicksilver/Mercury Idel Mixture Tool 91-866201 Please confirm fitment of MerCruiser parts with your serial number. A major advantage for small vessels and heavy loads. I would suggest tunring in till it stops (easily) then backing it out 1. I had a 15 horse that always had carb issues. 2007 90hp 2 stroke mercury idle issue put new spark plugs and spark plug boots on it. I was thinking that there might be a cap with an adjustment screw underneath where you couldn't mess with it, but the diameter of. Once warmed up, shift into Forward gear and adjust idle mixture to BEST idle speed while in gear. You can support the channel by using the Amazon Affiliate link when making purchases:https://amzn. Get specs on and see photos of classic convertible Mercury cars. The book says that when you put them back on to screw them in until they are snug, then back out 1 1/2 turn to set the correct adjustment. 1992 Force 120 - where is idle adjustment screw??? Thread starter rschele; Start date Jul 31, 2011; R. Make sure both carbs are fully closing at idle. Just a FYI,, and not to influence your final setting but my 95' 70 hp. Then starting from one end of head, crank the engine until each valve closes then back off the adjustment until a feeler gauge passes between the rocker and valve stem. Finally, what you want to do is set the idle mixture screw half way between the rich and the lean settings. All the idle mixture screws were replaced during rebuild. Thread starter lukepeden; Start date May 21, 2014; L. A downloadable version of the factory manual is available from this site. However, it would be best if you were sure that valves are the culprit before touching them. Jul 7, 2017 · Mercury/Johnson/Evinrude - Finding the sweet spot on Boat motor idle. Pretty sure there is only an idle screw on that carb, no idle mixture adjustment. 6 - Carburetor - Suzuki DT 115 Parts Listings - 1986 to. This is the only way I get my older triples, with two carbs, to idle correctly. Only the two primary barrels had them. Joined Jul 7, 2017 Yup I tried adjusting the idle mixture screw but it doesn't help. They can answer questions for any Yamaha …. Re: 6hp mercury wont idle help. Make sure you only adjust the "Idle Stop" screw, or the timing will be affected. Normally when you set the carbs, you start out at 1-1/2 turns out from lightly seated. Try running a very strong mixture of SeaFoam mixture with the gas or something like Techron Fuel. Routinely adjusting the idle mixture screws on a 2-cycle outboard motor will keep the engine running efficiently and provide power when you need. I found out 2+2 means the motor runs on 2 cylinders from idle to around 1600 rpm. Check the max advance at cranking speed. full counter clockwise Wide open oil pump. Idle mixture on 2-strokes have to be a bit fatter than 4-strokes to allow just enough 'richness' for acceleration. Re: 199 40HP 2 stroke Merc stalls at low idle. " I've read 5 turns on this forum before, but I've also read that there are different methods depending on model. Has anybody experienced something similar to this or have some insight on what might be the deal here? Also, as a general question, when adjusting the carbs, do you adjust one carb down to where the engine sputters …. Open the hood and make sure the engine is off before locating the air filter and removing the assembly. I think the Mercury 115-HP 2+2 has plenty of power. One of the many strange quirks about outboard motors that you will see nowhere else. Unscrew the wing-nut and any other connectors, and then remove the air filter entirely. I whipped the plugs out today and there was quite a bit of oil down in the core of the plug. When the air-fuel mixture is not properly adjusted, several issues can arise, negatively impacting the engine's. Late last season my boat developed an issue in that it would not idle and was at times hard to get started. Completely push in fast/primer knob and fully rotate it clockwise. Once the engine is warm it typically runs on the higher side of normal. Insert a screwdriver into the …. groomer jobs ----Idle mixture screw may need to be adjusted with engine in gear at the dock. Do this with the adjustment screw by turning it in 1/8 turn at a time, allow 10 seconds between adjustments. Start engine and set the rpms to where it just stays running. See if the flashes stumble up until the time the engine runs well. Carburetor fuel mixture screws caps? Thread starter Embarq82; Start date Apr 8, 2021; E. This is normally a cure for the problem of poor. until it seats lightly then, back off 1-1/2 turns. gine to idle for about one minute. Suzuki 1996 40hp idle inconsistent. I assume that your carbs are the same as mine on my 1992 40 HP 4 cylinder. The idle mixture screw is operating flawlessly and turning it in either direction has a dramatic effect on the idling so I know its. In some instances extreme changes in humidity or temperature and/or elevation can result in a rich fuel mixture at WOT. Start your Mercury 40 horsepower motor and allow it to idle. after replacing the complete manifold and elbow the boat is running great but I have a question when adjusting the idle mixture its looking like its wanting to be about 3. There is a port on the manifold where some models had a vacuum gauge attached as part of the instrument panel. The parameters for adjusting the carburetor on a Mercury outboard involve both the idle speed screw that controls the motor's speed at idle, and the mixture screw that controls ….