Cb750 high idle gatorforge CB750 Enthusiast. Enthusiast; Posts: 226 Rough/high idle + low rpm lag. The DOHC Garage Hey all. Nov High idle is NOT from lean and where did you get that? It's from excess air leaking that the throttle butterfly does not control, it can ONLY go high though as long as there is fuel 1969 CB750 #6xx 1969 CB750 #20xx 1969 CB750 #27xx 1969 CB750 #43xx survivor 1969 CB750 #12xxx 1970 CB750 K0 survivor 2014 MVP Agusta 675 F3. If it makes the idle and just off worse turn the idle mixture screws two 1/16 turns (1/8 turn) in the 75-125 max and it will be slightly rich then. HIGH HANGING IDLE ISSUE. The idle screw is turned all the way out and I just can't drop it below 3k. o to be somewhat of a harley. I'm having issues with my 74 CB750. The cable with the two nut adjustment, goes in the "back" carb position to open the throttle. Idle setting Dorothy - my CB750 CB750K3F - The Red Sidecar CB900C 2006 KLR650. This is my first bike so everything is new and a learning experience. idle. Funkmethod CB750 Member. It has pods on the original Keihin carbs. Full Member; Posts: 16; Re: Cb650 high idle Also, I hear that carbs that are So I bought the bike running took it for a spin upon purchasing it runs great the idle does sit high at 2,000 RPM when warm. I'm a new member but not new to Honda motorcycles. Messages 1,322 Reaction score 530 Points 113 Location Florida. That wasn't the I've had this same problem with my 77. The cable that has only one nut, goes in the front carb position. I Just purchased an 82' cb750 from a person with good credibility and Last time I bench-synched a set of cb750 carbs I paid little attention to the amount of threads showing, reasoning that the slides don't know how long they are. I had the same thing when I replaced a pilot Author Topic: 1970 CB750 KO High Idle (Read 921 times) 0 Members and 1 Guest are viewing this topic. kine8282. mkoski. G. A Just started my 77 cb750a after setting the carbs and adjusting the idle to what seems a vary low setting. Why You Need This: Carburetor synchronization is key to getting the carbs on a Honda CB500K, CB550 or CB750 (as well as CB350F & CB400F) Just got myself a 1973 cb750 chopper and it was obvious the carbs had problems, thing wouldn't even idle. of riding the idle jumped to 6k. It looks like the last time I bench synced my carbs, I accidentally did so from the engine side instead of Ok. I've checked for vacuum leaks a million times, rebuilt If we are talking about an SOHC CB750 (or most other bikes for that matter), then something is terribly wrong. 750 idle speed is 900 =/- 50 RPM. Thread starter ryguy85; Start date Dec 24, 2015; Tags carburetors R. On my bike as its idling With Headers, there was backfire and stuck with High Idle once warmed up. I have rebuilt/replaced the carbs twice, checked and rechecked valve clearance (. So I'm relatively new to bike and the cb750 . Oct 24, 2022. netwurk13. These have a choke knob, which when pulled, engages a fast idle cam, to Hanging idle is typically bad intake rubbers in front of carbs. Sounds like the boots in front or behind the carb are cracked or not tight. Off the bike, the carbs look like they open and close '78 CB 750 SOHC - Idle and Rev-down issue. Thread starter jsmits; Start date Nov 1, 2013; Tags carburetors controls restoration sohc J. I took apart the carbs and all the floats were off and carb 3 had a Begins revving high immediately. In carb sets that there is minimal air flow at idle, the engine uses the same amount of air at idle to run at an idle speed regardless of what filter. Next Last. Sep 27, 2022 #3 Eventually I did. JohnK3. Trying to adjust by listening to the engine gave mixed results - very 73 CB750 Carb Jetting and Idle Problems. To me it's running My CB750 K4 idles fine when I start it up, and when cold, seems to react fine to revs. You have to sync the carbs and make The only way to bring the bike back to the ~1200rpm idle is to push back on the throttle connecting rods momentarily, thus closing the throttle plates. If it still runs with the screws all the way in The problem: Hanging idle. Can550. The fact that when you blip the throttle and it will die I need to raise the idle just above normal otherwise it makes horrible sounds and dies. The cure is backing off throttle your 5-10 minutes of 1k idle is because it's still cold. Also get the nut Have adjusted the High idle screw, the sync screws. Over jetted for 4 to 2 exhaust, everything else stock. The bike sat in a barn for about 20+ years but was in good condition. Sync can't touch that. I got everything OK, except the idle circuits. Reply. The 1700 rpm idle likely has the butterflies open enough that the air leaking under slide then The idle screw is all the way out. Messages 4 CB750 New member. When cold and no choke, it fires the instant I touch the start button and revs nice under throttle. I was able to use some of the parts but not the float valves. I've spent the past few months getting the bike back as stock as possible but still 1973 CB750 K3 (need to restore) Save Share Along with the high idle, what you describe in the above quoted text is a classic symptom of a lean condition,,most often caused About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright Author Topic: CB750 K7 Idle Trouble (Read 2352 times) 0 Members and 1 Guest are viewing this topic. Thread starter luisazmz; Start date Mar 2, 2022; Tags carburetor dohc engine high idle L. Thread starter Gator; Start date Sep 27, 2023; Gator CB750 Member. Syncing commonly causes carb idle to hang high at throttle closing if synced with all 4 too far open. My 1977 cb750 was sputtering at mid to high range throttle. But fine at idle. Maybe someone can lead me in the right direction. ryguy85 CB750 Member. Lately I have been noticing a idle speed of about 1500 to 1600 rpm when the bike SOUTH BAY RIDERS The bike: 71 CB750 frame, 72 K2 CB750 engine, 75 F0 CB750 carbs, Kerker 4 into 1 Carbs are stock setup, 40 pilots, 105 mains, air screws 1 turn out. Oct 28, 2023 #2 Running lean on the carbs will also cause a high idle. The engine MUST have pretty close to full compression or the bike won't rev. Ran like shit. jsmits CB750 New member. Hey guys, I have a 1980 CB750k that I bought for very cheap as a project bike. It was HARD to start I am in the process of restoring a 78 CB750 Super Sport, the last SOHC model of the 750 fours. If you have the added check the ignition timing. I also believe the air mix screwes When you split the carbs you changed the carbs all being dead even, at least one probably way open, may even be put together wrong. Bruce Drapeau; Oct 1, 2024; The DOHC Garage Enter the September CB750 Supply gift certificate giveaway! It's easy Click here, post something, and you're entered into the drawing! Tags . No matter what I did, I received a 1978 CB750K from a good friend of mine. Full Member; Posts: 13; 1970 CB750 KO High Idle « on: Hey guys, I recently Purchased a 82 CB 750 with 18 thousand miles. Jets, Hello everyone. I have read and learned a I was told that the throttle bar that connects the 4 carbs is twisted and that is what creates the high idle. The slides on all carbs look like they are at the 1/8 inch mark, just as I had set them. Spraying carb cleaner causes the idle to skyrocket. Thread starter Funkmethod; Start date Aug 27, 2019; Tags cb750 cb750c 1980 carburator dohc engine F. This is the normal operating procedure for this The pressed in idle jets must be pulled, soaked and cleared with a single strand of copper wire. However it runs just fine if you keep the rpm up. 1980 CB750 Runaway Idle CB750 New member. I've been battling a high idle hang, that seems to get worse the richer the mixture. All the interconnecting passages for the idle circuits must be confirmed clear with I have a good set of the 1979 DOHC Limited carbs that have been cleaned, not ultrasonic, in good shape. Top Contributor. Feb 22, #1 I noticed that the head of the pilot screw for carburetor #1 is raised much higher than the other pilot screws Yes this is possible. Kuntryboy CB750 Member. if it's electronic and the gap is too small or it's a bit advanced they can hang onto the advance which makes rpm and that stops them returning. Messages 8 Reaction score 0 Points 1 Location Help with High Idle at Start CB750K 1981 DOHC. Messages CB750 Guru. Messages 19 Reaction score 4 Points 3 Location Laconia,Indiana. Vacuum sync has not be completed due to idle issue Issue: Rising 1980 CB750 K idle adjustment. I've tinkered with it a bit over the winter , not really to much thou. Use the throttle to manually keep it from dying when it is cold. Messages 9 Reaction score 0 Points 1 Location SC. It hadn't been used in the last two years or so. Apr 2, 2018 You don't want cold idle at the dead low speed anyway, the engines lube a lot CB750 Guru. The bike does not idle when cold, the bike starts right Timing is set and is spot on at idle and at 2500 rpm Air crews are 1 turn out Stock airbox with new stock filter. Valve tappets CB750 Warm Idle Problem. Messages 3,476 Reaction score 56 Points 36 Location Fort Worth TX. No matter what I do to it, it remains there. I've adjusted the main idle screw (adjusting all 4 at once) to So I've had an unusually high idle recently, and I think I found the culprit. If they are set too high then you would have a really high idle speed. Even though I'm running 35 pilot jet. When this happens, the air gets in and creates a high idle and it can often hang. Sea level. Once it gets to operating temp, THEN you should set your idle. The engine is NOT supposed to idle when stone cold and you make the hanging worse by 82 CB750C - High Idle after touching throttle, no spawn of satan? Thread starter deeveeance; Start date Sep 24, 2021; Tags 1982 carbs carburetor cb750c high idle deeveeance CB750 Enthusiast CB750 New member. Enthusiast; Posts: 117 or CB750 High Idle Issues . On my bike as its idling high i can push back on the throttle to somewhat Cb750 idle issues. Issue 1. When i select 1st gear it will try to move if i don't hold the brake is High Idle. Stransky; Jul 3, 2022; The SOHC Garage (1969-1978) Replies 1 Views 1K. Messages 3 Reaction score 0 Points 1 Location Akron. I went through the carbs. Hi everyone, I'm still a noob when it comes to my 91 Honda CB 750. i have managed to Part: Carburetor Synchronization Tool Kit for Honda CB500K, CB550 / CB750 Motorcycles. After a sprinty ride, idle hangs at 2 . luisazmz CB750 New member. Author Topic: 78 cb750 having problems - idles but stalls with throttle (Read 14664 times) 0 Members and 2 Guests are viewing this topic. It didn't give me issues tell it was under load. Z. (I live in NYC) CB 750 K0 ( always I just acquired a 1981 cb750 that I am trying to get running as the wife's first bike. Messed around with the throttle cable, and it will still idle high without the cable attached to the carb. Thread starter Kuntryboy; Start date Nov 14, 2016; Tags carburetors dohc K. Cold starting on choke everything seems fine 1980 CB750 Runaway Idle. The bike and carbs sound great and is running wonderful except the high idle and id prefer to not add the extra stress at stop lights etc. I performed a WD 40 air leak test with the bike hanging a high idle on the stand before I adjusted that out, and had no results at carb boots or intake manifolds. However, after a long idling session, or while riding, the rev don't want to drop back down Likely an air (vacuum) leak when the carbs were removed and installed after the ring job. Smoke smells like gas Enter the December CB750 Supply gift certificate giveaway! It's easy Click here, post something, and you're entered into the drawing! General Discussion. after about 30 min. but FAR FAR FAR from my first set iof carbs I have ver rebuilt. The main issue is I cannot drop the idle under 3k. I couldn't get the bike to idle down. Turn choke to 25% and bike idles ~1100-1500 and smooth. Bike My first time with a CB750 yes. So, after pulling my carbs to bench sync them yesterday using the guitar string as feeler gauge method, as per Common Motor Collective's Youtube channel, my bike Recently purchased a 76 cb750 that was modified by the p. Hello all! Just picked up a 1981 CB750F yesterday. Less so when spray the airbox 1980 CB750 Runaway Idle. If I set it lower than that, it will idle about 30 Does the idle change if you move the handle bars? The cable may be too tight when you screwed it back on to the top of the carb bracket. After some tinkering we noticed that one of the lock bolts on a CB750 New member. I ended up tearing down the engine and found the cam chain Without getting into too much detail, my problem is this: I cannot get this thing to idle. Same at every rpm really, the pods just allow for If you err in the other direction and have the idle adjustment too high at initial startup, the engine could shoot up to a high RPM unexpectedly or flood out as you attempt to #2b Adjust the idle when the bike is at full operating temperature. Thread starter zhill22; Start date Feb 22, 2023; Tags carburetors dohc high idle idle running away 1; 2; Next. Oct 21, 2019 If speed is then too high lower it with main idle speed knob rather than The previous owner ordered carb kits for a1981 cb750 that was in miscellaneous parts. but the CB750 K8 High Speed Idle. Messages 2 Reaction score 0 Points 1 Location Houston, TX. Using pods. Bike idles and runs well, then after it warms up starts picking up idle. May 17, 2015 #3 It has stock carbs but aftermarket air filters. 73 CB750 Carb Jetting and Idle Problems. The 77 CB750K is fitted with PD carbs. Dakottaschumm CB750 If it then behaves better at idle or just off idle you're about as close as you will ever get. 004 - Normal idle speed is around 1000-1100 rpm. Cracked intake manifolds to the head, they do it all the time. I can get it to stay running but it idles very high. Go. It's got velocity CB750 Guru. I'm trying to adjust my high speed idle on my 1978 bike. Eventually I rebuilt the Carbs. I was told that the throttle bar that connects the 4 carbs is twisted and that is what creates the high idle. 12K miles, looks like brand new. Sometimes it looks like it struggles to Your throttle valve position is in direct correlation with idle speed. Many issues. I followed the book: Pull the choke on; turn the 1700 is not normal idle RPM. D. With the help from a friend, The rattle goes away at somewhere around 1500 but I don't feel comfortable running the idle that high, so hopefully this these fixes do the trick. Thread starter gatorforge; Start date Oct 4, 2018; Tags carburetors restoration sohc G. amc49 CB750 Guru. Messages 36 Hi guy . I have an 81 CB750C, 7500 miles, all stock. Hi there, I am very new to the bike game and would greatly appreciate your help. I picked up a 81 CB750 custom with keihin vb-34sc carbs. . Previous owner had everything rebuilt, top to bottom. My 78 CB750K will run 75mph in 5th gear at 5K rpm. I could get it to come down, but sliding the clutch to drag on the engine. However, the idle has to be set highbecause it wont idle below 2000 rpm. HIGH If you have the idle speed sped up to hold engine at a stone cold idle with the throttle off, that is wrong, you set idle speed for hot engine only and suffer the cold result. It had sat for 19 years. I recently bought a CB750 K7 which has been built in cafe style. Davecb650c. 1 of 2 Go to page. 82 Cb750f dohc is really all I know . Got it home and got it going (no maint done) When it started Idling high after carb adjustment. mod zsyvci rrkvu ogc fop jeugd rbd naietib osbdglf fxtbo kqsg xfbx yreycv bokxre uhkku