XJ750 CARBS

Thanks for the help regarding my previous post ( XJ750 Carb Hoses ). But I am still having problems. I have cleaned the carbs, checked the fuel height, checked the jets, MAIN JET 106, PILOT 40, AIR JETS 70 AND 225, and even checked the valve timing. The carbs are HSC33 type with the extra air vents on the cold start. There is a picture on my previous post. The bike runs ok with the vent hoses blanked off, but it won't even start with them open. should these pipes be completely open at the ends. If the carbs have been changed, and the original ones didn't have the extra vent pipes, would they work ok, or is there something else different on the models fitted with HSC33 Carbs. Thanks.

 

If this bike is a 750 then the mains are running a bit on the lean side as the stock carbs for this bike should have had 120 mains in it. The hsc 33 carbs to my understanding came on the xj700. If these jets in the hsc 33 are stock then you should be running lean, lean is bad.
I have the same set of carbs on my xj700 and it starts fine without the extra hoses being blocked off. Sounds as iff the bike would rather suck air through the vents than fuel through the bowls. Dont know if the problem is related to the mains but it would be a good place to start. You should have 120 mains in that bike. The fuel level in the bowls may be a bit low also. The system is sucking air through the vent tubes rather the fuel from the bottom of the fuel bowl. If you can figure out why then you would have the problem solved..
When you cleaned the carbs did you take out and clean the little holes in the emusion tubes? They are known for getting cruddied up.
To take the emulsion tubes out the carbs need to be off the bike, Remove the top of the carb,spring,diaphram. Set aside. Remove fuel bowl. remove the main jet. The small tube in the center of the drop down on the carb body is the emulsion tube. This should press out. I used a small punch the size of the emusion tube to knock it out. light taps should remove it. Once removed, check out every single little hole in it. They should all be clear of obstruction. If not, take a small piece if copper wire and clean them out. Then finish up with a blast of carb cleaner. One cl3eaned it is time to reinstall. These only go in one way. There should be a small cut out in them which lines up with a guid in the carb body, This should allow the emulsion tube to set down fully. Make sure all emusion tubes are fully seated or frustration will occure when you try to fire up the bike. Hope this helps
Check out ric-o-matics cleaning the carbs the whole nine yards when you get a chance. It explains everything on the carbs.

 

The carbs aren't off a Maxim 700 since he lives in the UK. They are off a XJ750RL. But I can't find where those hoses connect to. If Samsr can answer that then we can figure out what to do with them.