carburetors

Anyone know if it's possible to use the shorter rubber carb intake boots over the slightly longer ones? Will the boots still align with the head flanges? Thanks..

Hello I bought a 1978 cb750k four. I had to take the carbs apart and rebuild them. Now I have a little spring that I can't figure out were it goes. It's just like the one on the accelerator pump but smaller. Does it just go inside the bigger spring? I read in a discussion in regards to another...

Hey all, at this point I'm a regular on this site and am learning as I go. Right now, I'm experiencing an issue with my 78 model that so many have had and will have. A rough idle. Only difference is mine doesn't die on me! She sounds more like a harley than any of these bikes should while...

Previous owner had them and the harness ran in a way that interfered with the fuel tank so I was looking around on the bike and the internet and started wondering how others had these ran? I attached pictures of what I think looks best but not 100% sure.

Hi, 1971 CB 750, runs well, carbs synced. With gas off, slowing down I get allot of sputtering as I down shift. I have check plugs and moved needle to lean out mixture with no improvement. I am guessing it is running rich. All jets are stock and I have stock pipes & stock air cleaner. Top end...

I understand that every bike has different requirements for carb jetting, but I feel this is super weird. Let me know your thoughts. I just finished a build and now I'm trying to get the carbs in line. I changed to UNI air filters and a 4 into 1 exhaust. I expected a significant increase in...

Hello everyone, I just wanted to share a design I made. I have a 78 CB750 with the Keihin carbs. I changed out the throttle shaft felt seals and accidentaly knocked out one of the throttle shaft plugs on the number 1 carb. I guess while riding it came loose and got lost. I looked everywhere...

Hello I have a 1980 cb750 that sat for a year. it was leaking gas so i took to a local mc shop. they rebuilt carburetor, charged me $800 and now say that there is a brass rod that they cannot find. (or dont wsnt to be bothered) i know there were carburetor gurus on this site before. any...

Hi ya I remember a mod done to the carb slides machine .008 off the lower back side to help the transition from violet jets to main jets. I have done this on my 71 and when riding it is a bit smoother but when shifting the rooms do not drop far enough to make a nice smooth shift.I have gone...

This post is really asking two questions. Is there a way/What’s the best way to tune the carbs without those pressure gauge setups that I see on youtube? Also, my bike used to run fine-ish, but lately it had been choking itself out. It would run fine for a spell, then stop revving past 3/4k and...

Just wanna know what you guys would do......I just cleaned, derusted and seal coated a gas tank. Im putting the bike away for the winter and have not put any fuel in the tank yet. Would you fill the tank with gas for the winter or leave it dry untill I take it out of the shed in the spring...

Hi folks. I'm rescuing a 1977 CB750F from many years of disuse and neglect. The brackets that hold the air box to the frame are rusted up pretty badly. When I tried to disassemble the box to remove them, I've encountered the spacer that goes on the long screw that clamps the two halves...

Hi Everybody, I am trying to figure out want exact size of fuel line I need for my 73 CB 750. Suppliers seem to have 2 or 3 I.D. sizes and I am not sure which one to purchase. Thanks

Greetings. First post new member. I was gifted a 79 750K with around 35k km's on it. Its in factory configuration aside from a 4 into 2 exhaust system that is ok at best. The exhaust has no bypass. The bike starts perfectly warm or cold and after a decent warm-up period, runs and drives nicely...

I'm a new CB750K owner with a bunch of questions. In addition to the OEM 1981 CB750K gas tank, are there other model and year gas tanks are compatible without any modification to frame or tank? Will any CB750K tank from 1979 - 1982 work? What about previous years? What about CB750C and CB750F...

Bike runs, idles steady. Carbs have been pulled and gone through twice. Manifolds on both sides replaced. No indication that the bike is running on only two cylinders and it actually sounds nice at idle. Figured since I got it running fairly well id do a carb sync. Cyl 1&2 look good - both...

I have been working recently on a 71 cb 750 that I purchased,I could not get #2 to fire ,I checked compression,spark they both seemed ok ,I could not get #2 bowl to fill with fuel,I also checked the bowl vents on advice from the forum,finally I pulled the carbs and found that #2 slow jet was...

Hello, I recently bought a 1977 cb750 k7, however, the fuel lines weren't connected. It looks like the carburetors have two inlets on top, but I can't find which one connects to the fuel tank or if both have to be connected. Could anyone point out what each inlet is used for?

Hello, can some friendly soul put up a video on how to put the airbox back on? Its seems impossible. I have them almost back on but there is a hose under the airbox making the hole thing to high. I just cant get it back on properly.

My uncle has a few cb750 cafe racers and we have been working on getting her at a steady idle and to rev appropriately it's running on choke and only for a limited time he has changed multiple carbs have tried different afr have good spark going to the plugs changed the cdis multiple times and...

1980 dohc came to me as non runner carbs in pieces got them all cleaned up and together. Bike starts but sync gauges are all 4 rapidly bouncing in wide arc. Make me think timing or valve adjustment. But I'm a harley guy haven't worked on a cb in more yrs than I care to remember. Any pointers in...

When disassembling the automatic fuel valve (16970-461-771) I found that the gaskets were weathered and broken. I've been scouring all the parts suppliers and had no luck on finding the gaskets only does anyone know where I can find just the gaskets?

I have a 1982 cb750k2 engine with Keihin VB52A inline carburettors. The standard size main jet is 102, mine has 98's installed. The previous owner has four DNA airpods fitted. Above 3500 rpm, when the main jet cuts in, the bike pops and bangs and stutters. I think the jetting is too lean...

What is the difference between the vb42a and the vb42d carburetor?

'79 CB750K. Idles rough at cold start. Previously I had to hold the throttle open for about 1 minute or it will die. Once it warms up a bit I can release the throttle and adjust the choke. The other day it cut out after about 1/2 a mile. I thought it might be flooded, so I waited a couple of...

'79 CB750K. Engine turns over, but I have to hold the throttle open to keep it from dying. I warm it up like this for a minute or so, but as soon as I release the throttle it dies. This started the other day when I was riding and all of sudden it cut out after about 1/2 mile. I thought maybe it...

Any suggestions on how to evacuate all fluids from the gas tank? I have a 750L and I need to treat it for some rust in the tank and I can’t seem to get all the gas out of the tank to treat it. I was considering compressed air to try and force it out where the shutoff mounts???

:confused: Jamsr CB750 New member Messages1Reaction score0Points1LocationMaryland 2 minutes ago 1979 750L I scoped the gas tank yesterday and there is a rust build up on the bottom corners where the metal is pinched together. Looks like it maybe could flake. Any ideas on what to do? I was...

PLEASE Help, I have a 91 cb750 nighthawk not getting any fuel, I replaced the petcock to find out that that is not my issue. It’s the smaller vacuum line that look like goes into the engine. I am not getting any suction to the Petcock is not pushing fuel thru to the carb. Please if anyone can...