Mikuni carb wont start. the only other non-stock item it has is an exhaust. Pull the starter and see if it shows any signs of life. You can search YouTube for Mikuni videos and see how to do this if you aren't familiar with it Jan 20, 2010 · Ok so I put the cyl at ATDC and took the covers off and was able to "roll" the pushrod with no problems. Dec 12, 2023 · I've always had very good results with use of the vm22 on all the bikes I've used them on and have actually yet to run into a bad one myself. i can hear the starter whirl and try to start the bike up but it just won’t turn over. Jun 16, 2016 · Parts: gx390 carburetor and 35lph mikuni fuel pump. I realized that after I spray carb cleaner in the carb is when it will give me the kick back. Sep 3, 2016 · The carb is a BS34 Mikuni and I have no clue if the main jets have been enlarged. Jan 23, 2018 · Perhaps the most prolific dirt bike carburetor of all time, the Mikuni round slide is a simple, dependable high-performance fuel mixer that is easy to tune. If it doesn't start I hold the decompression lever open and throttle wide open and pump the motor to clear the cylinder, then kick again with wide open throttle. Checked that fuel goes through the lines from the fuel tank 4. Jan 15, 2021 · What’s up THROD SQUAD you have asked and I’m here to deliver on how to adjust your amazon mikuni carburetor to get it to run correctly. We use 25P jet sea level (we have rode up to 10,000ft) Also open up airbox,pro vents,Uni xr500 filter. You have restrictive airbox/filter,header,muffler. I do not have an inline filter, and I did not check to see if there was gas going to carb. The Mikuni American Corporation is originally a Japanese company that was founded in 1919 by Mikuni Soichiro. Niche jets their carbs fairly well, but fine tuning can be done after you getr running. This applies to other small engines. How to clean out a Mikuni carburetor on a Subaru / Robin engine that won't start or is surging. Checked the fuel pump 3. One major difference between the stock Carb and Mikuni is the throttle valve, the stock carbs comes with a butterfly type of throttle valve, whereas the Mikuni has a cylindrical throttle valve and goes up and down as you open or close the throttle. When this condition occurs there will be no spark. I can't find anything wrong with the carb. Big tube header,Hi flow muffler. Thanks for the help. I’m here to help you Nov 6, 2014 · The old carb was cleaned three times and it still ran rough. mikuni carb rebuilt but wont start. May 3, 2020 · Got a hand-me-down trail boss from my dad. Jun 22, 2020 · The choke system is like a mini carb inside the mikuni pumpers, and should allow it to start. Checked spark on both sparkplugs 5 Looked for leaks on the vaccumhose Dec 22, 2012 · I ohm-tested the Stop-Run-Start (SRS) switch tests fine per wiring diagram. Proper enrichener setting as you've outlined certainly plays a big part, but having the right throttle valve cut away, and correct type of fuel for the engine's compression ratio can also make a big difference. I covered the install in the other thread but basically if you have a 2000 or older TW you need to swap out the airbox to carb boot to the 2001 or newer because it is 1/2 long Oct 31, 2009 · Mikuni 26mm carb problems. i'm going to clean the mikuniu carb up and see if it will run. Note how the throttle cable was on carb,if you put it back 180 degrees from where it came off, the slack is gone. Just got my '98 XR4 back together with the new 1 over Wiseco. Apr 28, 2009 · i'm going to say that the pilot is so small that it can't get enough fuel to start it, BUT here's the usual rundown. The OEM Mikuni carb was so old and clogged up that no gas was getting to the engine so I decided to replace. I installed them and tried to kick it a couple of times and it wouldn't start. I have messed with the air/fuel mixture and idle screw but to no avail( no thorough testing done). Except for the initial start up on the coldest days, a Mikuni equipped stock class racer should start well without any external aid. The Problem When I first start up the bike I have to run it on choke for awhile before it is able to run on its own, and there is no throttle response until it is warmed up. Still wouldn't start. If you're up Feb 10, 2011 · If it is set up correctly at the dealer upon purchase. the best way is to assemble Aug 22, 2010 · Hi all. 1/4"inch "T" fitting and line. I made sure that gas is getting down into the carb. Repaired Feb 22, 2010 · The Mikunis choke is an actual start enrichment circuit. The idle jet could be plugged too causing a lean stumble off idle. The bike won't start unless I take off the choke. JPG. You can also find jets and parts easily. Also it dies when I close the throttle. Mar 6, 2012 · My 1974 Norton with a single Mikuni will start and run with the choke on. 5 turns out. they do it in less than a minute. I'm at least back where I started : Thanks for asking. Answered in 9 minutes by: 4/10/2015. lets start with what you have checked. THEY ARE READILY AVAILABLE ON EBAY AND AMAZON FOR AROUND 40 DOL Jul 27, 2022 · VM22 carburetor won't idle on a Predator 212 FIXFound out the reason why the VM22 Mikuni-equipped Azusa minibike with a Predator 212 wouldn't idle. the first day the bike ran super smooth but at the end of the day on day 2 the bike will no longer turn on. After replacing, it still only idles when choked. It was running on this XR's only Mikuni this Dec when I bought the bike. I decided to buy the new carb vs rebuilding the old one. i kinda cleaned the carb with carb spray and checked for I tried cleaning the carb, changing spark plug, adding fresh gas, etc. I still have the XR's Mikuni Flatslide Carb that came with the bike and was the last carb that did run. Maybe once a year- kind of subjective opinion on my part for reference. I can see the slide/needle in the carb (airbox off) lifting up but engine won't rev. I've discovered a few different routines that work well with the Mikuni. Then release both, bring engine to TDC and kick. My dad pulled the carb out and cleaned it up. I live at 5000 elevation. I also made sure the floats were at 24mm from the gasket seat. One is to start kicking with the choke on. I opened up the bowl and it was empty, once I opened it up it started to fill. You can drain float bowl on mikuni with the screw on the bottom of the float bowl. Well i've figured out after all these months it is a fuel problem. but this keeps happening. Stock motor,or 440. I had read on this forum that most installed the new carb and their machine ran perfectly. 5 pilot jet, and extended fuel mixture screw at 2. Kill switch, spark, are you getting fuel to the carb, is your fuel valve closed. QUIT banging your head into a wall. If I spray carb cleaner in the air way it starts strong then dies SO! I know that the problem is that its not getting fuel. Nov 4, 2014 · A bike will only start with a dead battery if it has a separate winding on the stator for the ignition. It usually starts for a couple seconds and dies. It will chug occasionally but die within a second. Once warmed up, no throttle at all and starts 1st kick. Will it start with starting fluid? Start over and check all of the small things first. Jump to Latest If that doesnt work, Guess I wont worry about it and just let it be. Runs fine for a month, puts on a Mikuni, won't run, so puts on a 2nd Mikuni, still won't run. i was riding the bike earlier (day 2) and when i went to shift into 3rd gear Front and Side view for the Mikuni VM Source: MikuniVM User Manual Throttle Valve and Needle jet. Jul 3, 2022 · Try to purchase Mikuni OEM parts for this carb. Usually only takes 3-4 kicks. Still, many Mikuni-equipped dirt bikes are May 16, 2011 · I have Mikuni bs34 carbs on my kz750. Things i have done so far is 1. So i've been working on my engine for many months trying to pinpoint why the engine either wont start ,wont stay started, would only idle if choke is off but only runs with choke open. . It can cause pressure to force gas past your pop off. The difference with the Mikuni over the stock carb being, the engine responds well to slightly wicking the throttle open at the very bottom of your kick. Once running it seems ok. Sometimes there was smoke coming out of the air filter. You do not want fuel dribbling from the carb bowl onto the HOT exhaust pipes ! Aug 5, 2016 · ORIGINAL CARB WAS HAVING IDLE AND COLD START ISSUES SO I SWAPPED IT FOR NEW 26MM MIKUNI CARB. Jun 24, 2018 · The carb will come off today, strip it again and check for any blockage or other anomalies lurking about. Is this data for their kit or the way Mikuni commonly sells this carb? MAIN JET 4/042-Size 310 PILOT JET VM22/210-Size 35 NEEDLE JET Jan 9, 2007 · The choke in a typical Mikuni carb is similar in that it has a long tube that reaches almost to the bottom of the float bowl. I’ve made sure there are no vacuum leaks and I’ve thoroughly cleaned the carb. Li May 2, 2013 · Carb Cleaning 102 Written by MShively Most carburetor problems seem to come after the motorcycle was stored or not started for a while. Make sure your gas tank vent valve works. Feb 12, 2019 · The electric start doesn't suck fuel from the carb. As long as the carb specification is correct, and the timing ok, tickle the float chambers but do not flood, with the clutch pulled in, prime approx 10 times with the throttle a third open, then release the the clutch , prime slowly normally two or three times, then with the throttle closed give it a good kick, if it doesn't start, prime slowly again with the throttle just off the stop Feb 28, 2023 · Sounds like he doesn't want to listen. In fact I took the Mikuni carb from my Combat and I get the same results. Jan 21, 2023 · Hello, i have tried to get my old Winha 80 with a Mikuni carb running for the last 2 days but now i'm out of ideas. When I try to feed it fuel, fuel doesn't even go down the line into the carb. 2 MB Views: 2,080. Me like a number of VM Mikuni owners added an Amal spring inside of the Mikuni spring to prevent throttle sticking at upper revs. Not really sure what to do from here. Take the carb all apart and spray carb cleaner through every hole and clean every part thoroughly. After a long night, no smoking gun and no start. May 15, 2016 · Guys, all I know is the carb shop uses a screwdriver and they twist the screw to a certain way to adjust the carb right. It's a 2003 S, stock exhaust, stock fuel petcock, stock mikuni BSR36 carb, JD jet kit with the blue needle on the 3rd clip, 155 main jet, 22. I will do Yes that creates a high vacuum which forces fuel to get sucked out of the carb, check to make sure your air screw is adjusted, and all the jet passages are cleared, even the air jet, best to just basically go right through it, the other thing is make sure you didn’t accidentally put the carb slide in 180deg off, that’ll prevent the slide from dropping all the way down, definitely make sure Aug 1, 2024 · Just bought a brand new carb for my ‘01 Grizzly 600. It will go into the ultrasonic tank as well. I tried cleaning it twice If it won't start it's not your main jet but could be your idle/pilot jet Make sure you don't have a vacuum leak. Sep 28, 2023 · Their not mikuni OEM jets but they are clones and equivelants like most others Ive always started w/125 main because the stock jets that comes w VM22 carb's are usaully too smallHad it running just fine on the test stand breaking it in. I just don't know the secret, they also won't let me see how they do it because obviously I'd figure out how they do it. Also, with the stock carb you want to keep the throttle closed. May 16, 2023 · A few weeks later I get to the launch and it won’t start. I have tried eveything I can possibly think of including different needle tapers. This one is on an Ariens snowblower with a model SX17 6HP en Nov 5, 2006 · The starter circuit onthe Mikuni is like a little mini-carburetor circuit--if the engine suddenly won't run except on the starter circuit, then something is clogged and not passing gas. The 36 pumper is great choice. Thus, my reason for the new carb. The pilot screw runs best at 1 to 1. I sprayed carb cleaner Apr 4, 2023 · History of Mikuni. Initially, the company focused on producing small machinery and later expanded into the production of carburetors for motorcycles and other small internal combustion engine applications. Assumed that this had something to do with the float filling the fuel bowl. Jul 30, 2020 · Some carb settings were suggested and I tried them and it wouldnt start for me going any leaner than it was. But the weird thing is, that when the carb is attached to the manifold it does this, but when it's off, it flows perfectly fine. When it stops popping/trying to start, turn the choke off. You can't grind, deburr or drill out carb parts period ! Unless you get lucky !!! IMO; shit can the stuff you've already done with this Mikuni and start from scratch with OEM Mikuni replacement parts. So it won't idle. Mine had stuck at a dangerous moment. Ask Your Own Small Engine Question. When it's open, the carb could completely bypass the idle circuit and run solely on the EC. Attachments. Oct 3, 2015 · Hello everyone, i recently purchased some brand new mikuni vm34 carbs from TC Bros for my 78' XS650. Since your bike is E-start, the stator most likely charges the battery and everything runs off the battery with 12VDC like most street bikes. Black smoke still coming from the pipes and reeks of gasoline. Mar 26, 2014 · hey! i have a 1992 kawasaki EX500 and i just got it about 2 days ago. Jun 23, 2018 · hey i have a brand new 22mm mikuni carb and the carb wont start unless i put starter fluid in it then runs, any ideas what the problem may be and if anyone could give me a guide on what screws do what and how to adjust idle and air ratios would be much helpful. Apr 28, 2011 · The unit has a Suzuki engine (VMFS-326763) with Mikuni Carb. If fuel is not being pulled into the engine, it means that air is not being pulled into the engine or there is a blockage between the carb venturi and the float bowl. Share this conversation. It sounds like the pilot jet is clogged, since this occurs only upon low engine rpm with the throttle closed. I’ve even tried sticking a washer under the needle clip to raise it even more. Also threw in a new spark plug and I confirmed it's gap. But, bike wont start. the tricky part is how to configure the carb to the manifold since there's so much adjustability on it. Here are the basics for installation and tuning of the Mikuni (Chikuni) carbs for Predator 212cc engines. Once shut off it immediately will be very difficult to start again. If you're looking to replace your OEM carb with a genuine Mikuni carb, you'll find Niche Cycle Supply and MAP Cycle will have what you need. MAP Cycle has been providing vintage, British bike enthusiasts with parts (including Mikuni carb kits) for over 45 years, while Niche Cycle provides parts for Japanese, German, Italian, Spanish as well as Aug 5, 2015 · When it won't start when hot, hold the manual decomp lever and kick the engine over several times with throttle open. what causes this? Jan 3, 2021 · My XT500 motor with a Mikuni carb won't start when cold unless I hold the throttle wide open. Discovered that if I tilted the unit to the left and then the right it would start. It will fire a couple of times (but only the rear pipe is warm) Here's what I did so far: - checked pushrod clearances numerous times - re-set the points (did not replace points or condenser) - pulled the cam cover and checked cam alignment Dec 28, 2016 · Hey guys, I'm having trouble getting my bike started and was hoping you could help. Max rpm is about 6600. Jun 17, 2015 · All things considered, the round-slide Mikuni is an excellent carb, with a wide range of tuning capabilities. The flow of air through the carb results in low pressure, which sucks air from the float bowl into the air stream. Aug 25, 2021 · My carburetor is in fact the real VM22-133 Japanese Mikuni, not some Amazon knockoff. I put the carb all together but still wont start. DSC00913. I saw lots of threads on here similar to this one, but none that said its hard to start hot. OBVIOUSLY it's not the carburetor. Gas fumes in bilge is not good on start up! 1. from my experience whenever there was a bogging problem it usually traced back to a air leak or generally lean condition. Now to get the new Mikuni adjusted right. A properly jetted carburetor will leave a nice grey scale color in the end of the exhaust pipe. If your at sea level,running small 15p jet. But, it is activated by opening the choke plunger and subjecting the choke tube to a very strong pressure differential (partial vacuum) from the downstream side of the closed throttle. we have Aug 23, 2010 · It does sound like slide sticking. That seems to be the logical step to take with what I have. After that I tried cleaning the chinese mikuni carb I had on the engine as well as checking jet sizes so i could order a bigger size but when I put it all back together the engine would no longer start at all for me even on my old Nov 4, 2021 · Turn off gas so carb does not get fuel. Before the Mikuni gave out on me it only idled with the choke on for several years. On these, that "choke" isn't a choke. Sounds like it's being held back like a rev-limiter. But small changes in the right direction won't show any negative symptoms-{ basically its reading a voltage like a potentiometer and X voltage= closed to the ECU so if the voltage is less than X it still = closed to the ECU. It's an enrichment circuit. Took the carbs off and gave them a clean and now it is extremely hard to start and will only start with fuel off and once the fuel is turned back on it idles at 2500 rpm in the water. Apr 23, 2009 · My '74 XLH refuses to start: It spits raw fuel and sometimes flames out the carb. I put new plugs in and still no start Battery is telling me 12. Use 100% stainless clamps. Alternate on and off til it starts. You may want to hold throttle open a slight bit Sep 14, 2013 · I got four bikes out this week, three of which were kick-start. Also it will start dumping gas out the carb overflow tubes. do you have spark? are the reeds ok? check the compression, have you removed the TORS? Feb 2, 2023 · i just installed a new mikuni clone vm22 carb, and it won’t start? it’s getting gas into the bowl. Apr 7, 2011 · now first everything is set dead nuts on,,, any other carb this is a 3 kick ironhead, Trying a VM38 round slide carb an for the life of me it wont start cold????? my SU starts better then this carb cold, an SUs are hard to start cold (remember kick only here!) any thoughts?? It will try to start an turn over an couple of revs Jan 11, 2023 · I swapped the TK / Mikuni TW carb for a Nibbi a while back as I noted in my 'picture' thread here 1999 TW - Upgrades Now with Pictures! I want to bring y'all up to date. If it won’t idle after warm up with choke off, then gradually increase idle screw/slide height. Oct 6, 2021 · Hi, I have a mikuni 22 that I'm having some problems with. Apr 1, 2018 · If it is a brand new carb is could and probably does have some crap in the carb. You can clean the sparkplug with carburetor cleaner and re-use. PUT the stock one on, drive your kart or bike and have some fun. The bike won't start unless I open the throttle while cranking. Sep 27, 2013 · It will start in 2 to 4 kicks with the choke/start circuit on, but takes probably 10 or more kicks to start when its hot. Sep 19, 2014 · On bigger pilot jets pumper 36. I sure do feel like a damn I recently put a new 24mm flat slide Mikuni carb on my predator 224 and it will not start. Jun 23, 2024 · So I switched back to an old CV carb instead of the mikuni. Cleaned the carb 2. I took the carbs apart, cleaned all the jets and passage ways with some carb cleaner spray. I guess in the fall, it wouldn't start any longer. It started once when i adjusted fuel levels very high, but it run rich. It is harder to jet,when bike is restrictive,but necessary using quite muffler. It started right up and ran great in the summer of 2019. However since this is a problem that showed up after a rebuild and it worked OK before maybe rerouting cable to minimize drag all that is needed. Jul 29, 2014 · My carb the top line is return, the bottom is the in line. This is the data posted on Allensperformance website for the VM36. Bike starts and idles in both Run and Start position but won't rev any higher. 2. Have had trouble starting the unit for the past few years. If it won't start or only runs with the choke lever pulled out, you have one or more jets obstructed by gummed or varnished fuel. So I'm guessing the issue with too much fuel coming in isn't a carb problem? I don't know what else May 29, 2014 · (Mikuni Vm20) I cleaned out the carb due to stuff in the tank. Here are some simple tips on how to dial-in your round slide. Carbs are very well cleaned, pod filters, 140 mainjet and 40 pilot jet, pilot screw 2 1/2 turns out, fuel level is adjusted 3mm from carb body. 23 volts, plenty of gas, I see the jet spraying fuel. Exhaust Exit is Black and Sooty - Excessive carbon buildup in the exhaust is thick and overly grimy. ( I know it's not really a choke) When I turn the choke off engine will die. Open throttle and give a two second spray of starter fuel into carb. kcwtqu lffxm zthkm ioga kermot pjps occwcw lome sco bgot