STOP. You are going to kill the starter doing what you are doing. Take the carbs off and fix them properly. Have a fresh set of plugs ready too.
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Chudman1
CB750 Enthusiast
Copy
I’ll order the parts
Chudman1
CB750 Enthusiast
Would you recommend replacing all jets as well?
I’m getting lost with what model I actually have, given from the look of the float pins I have a 1980 cb750f
But the jets look different to what I can see online
You can find the number of the carbs on side of the flange where the float bowl attaches.
Here is a list of the carburetors by year and model.
http://www.hondachopper.com/garage/carb_specs/carb_specs.html
Here is a list of the carburetors by year and model.
http://www.hondachopper.com/garage/carb_specs/carb_specs.html
Chudman1
CB750 Enthusiast
Thank you
You don't have an air filter of any kind, I see. That means you're sucking in a ton of air and I bet the jets aren't giving you the right fuel mixture. Even after a complete carb disassembly and cleaning, you need an airbox and filter on the back of the carbs for the carbs to properly fuel the bike, or you still won't get it to fire.
Chudman1
CB750 Enthusiast
Okay, I'll put the pods back on and give it a go.
I gotta take the carbs off again to fix the choke anyway, and the 3rd carb started overflowing so that needs attention too.
I think I'll still get the rebuild kit and do a proper soak and replace all the seals.
With the pods, I haven't touched the mixture screws.
Is there a base line or a starting point?
I gotta take the carbs off again to fix the choke anyway, and the 3rd carb started overflowing so that needs attention too.
I think I'll still get the rebuild kit and do a proper soak and replace all the seals.
With the pods, I haven't touched the mixture screws.
Is there a base line or a starting point?
Hard to say. Not all pods are the same. The amount of air they let thru is the variable determining what jets to use in your carbs. I would suggest getting the bike to fire first. Then tune the jetting. Do not run the bike lean long or you'll damage valves, etc.
Chudman1
CB750 Enthusiast
I double checked the wiring diagram to see if anything was missing, I had missed the auxiliary power to the reg/rec
I put the pods on and went full choke, bike almost kicked over today. Could hear what sounded like some knocking and the starter clutch slipped again so I left it at that.
I'll send through another vid
I also took out cylinder 3 & 4 plugs, 4 was clean, does that mean no fuel was getting into the cylinder at all?
I put the pods on and went full choke, bike almost kicked over today. Could hear what sounded like some knocking and the starter clutch slipped again so I left it at that.
I'll send through another vid
I also took out cylinder 3 & 4 plugs, 4 was clean, does that mean no fuel was getting into the cylinder at all?
Chudman1
CB750 Enthusiast
Chudman1
CB750 Enthusiast
That did sound close. If you have stock jets with those pods then there probably wasn't enough gas to getting to any of the cylinders. And so it isn't likely to fire at all.
Two things: some pods cover the air circuit on the intake side of the carb, preventing them from working at all. Second, when you try to start the bike have the throttle wide open. That will engage the main jet as well as the pilot and might help get it to bark once or twice.
Two things: some pods cover the air circuit on the intake side of the carb, preventing them from working at all. Second, when you try to start the bike have the throttle wide open. That will engage the main jet as well as the pilot and might help get it to bark once or twice.
Chudman1
CB750 Enthusiast
Would you recommend going for bigger jets with the pods Brett or changing the filters completely?
kirky
CB750 Addict
Chudman 1 i had problems when i rebuilt my carbs every book and other places i looked it said main jets 102, i thought someone i messed with my carbs and took out the 75's and fitted 102's when rebuilt it was choking the engine at 5000 revs and everything pointed to electrical problems [ melted cdi's and a cracked coil ] it turned out it wasn't electrical though , mine is a 1979 also but a jap market import with the same carbs as yours. after a long effort of research the air box intake and main jets turned out to have a difference from the export bikes. many people will agree the air box correct for the bike and the correct jets is the only way you get these bikes running as they should without causing you loads of headaches. the only way i got mine to perform with the 102s was to leave the air filter cover off giving the engine more air. i have now put the 75's back in. i also set the screws under the carbs 1/2 a turn more out than the book said and it was a pig to start. ps carbs were built a great expense at a shop with all new honda bits, i told them to put the 102's in because at the time i was going by the book. apart from the screw settings
Chudman1
CB750 Enthusiast
Hey Kirky
Looks like I have the VB52A(E) with a threaded idle jet, thought my eyes were playing tricks on me but I guess that’s the joy of living in Aus
Is that the same model you had?
https://motorcycleproject.com/text/specs_revised.html
Looks like I have the VB52A(E) with a threaded idle jet, thought my eyes were playing tricks on me but I guess that’s the joy of living in Aus
Is that the same model you had?
https://motorcycleproject.com/text/specs_revised.html
kirky
CB750 Addict
mine are VB52A(D) i don't understand the E or D bit
Chudman1
CB750 Enthusiast
kirky
CB750 Addict
no mention of mine, as i say it was a jap domestic market bike imported to UK and try as i do can never find info on it except many parts on the bike are the same as the european cb900f. i have been told they based the jap market 1979 cb 750FZ which is mine on the european 900f the handle bars and sprockets and cables etc, when i was ordering cb750f parts they were wrong and i realised the parts i needed were for the 900f, my books only relate to european/ canadian and american hence my mistake with the main jets.
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If you have the airbox and filter, try to get the bike running with those. Then mess with jetting with the pods. If you don't have them, increase both jets by two numbers. That's where I would start.
Good advice from Brett. Put a stock airbox back on it. If you don't have one I'm sure someone on here can help you. Once you start using pods and different exhaust systems, carburetors become an issue. I couldn't tell on your video if you have stock exhaust or not. This will be the last time I say this, fix the carbs properly, and as Brett said, put a stock airbox back on it. Don't forget the proper clamps.
