I have a 93 cb750 that has been running pretty good for the 5 years that I've had it. There is one issue that has been getting progressively worse since I have had it. it takes a while to warm up. I start it up with the choke and let then leave it on until it runs easily with out it. But then when i ride off it runs like it is choking for fuel or air until I can throttle through 2 gears or so. The carbs were cleaned and adjusted last summer and it ran great for a week but then slowly went back to this routine. I can't find the fuel filter on the bike or in my repair manual. I found a filter cup that fits in under the tank. Is this what I should be replacing? Will this smooth out the rough take offs? It is getting bad and a bit dangerous when I don't have a long stretch to throttle through it.
Cant say I have seen the 93 but a couple things you can try are to just remove the filter if you can. See what happens when you ride. If the problem goes away, well then you got your answer.
If it still happens, then obviously it is something else.
Couple things it may be:
the fuel cap may have a breather to allow air in so the tank does not become a vacuum. If this is dirty, air will not come in fast enough to allow fuel to fill the bowls. DOes not sound like the issue.
What this sounds like to me is that the bowl level may not be correct.
I do not have the manual for a 93 but maybe someone here does or maybe you might want to pick up one.
Find out what the float height should be and make sure the level is adjusted accordingly.
Also, all the bowls should be at the same height. To check this, you should have overflow drain tubes, hook up clear tubing in place of these tubes and curve them upwards, then open the drain screws. The fuel will fill the tubes to the same height as the bowls. They should all be close to even.
See what might be happening is with the choke on, there is enough of a vacuum to draw the fuel in but once you take the choke off, there is not enough vacuum in the idle circuit till you have throttled up.
This all assumes your bike has carbs.
The ride IS the adventure. The destination is just to get gas!
I would try anything Re-Run recommends. However I had the same issue when my petcock was turned to main. This was an issue since the first day I purchased my bike. I had to run it on reserve all the time. This winter I had my tank powder coated and when removing the petcock discovered the o-ring was junk. Well you can't buy the o-ring itself. The entire filter assembly is sold together. So I coughed up the $33 and was happy to find that the bike now runs on main with no issues whatsoever. I guess the main feed line maybe had some kuggha (very technical term, kuggha) in it. Granted, my bike is a 76.
Well I took the main line off the petcock, attached a long piece of fuel hose to it and ran it right to a gas can, then opened the petcock and went in the house. It isn't a bad job. One thing I should tell you, according to the Honda dealer once you take the nut off the petcock the o-ring needs replaced. That only comes with the strainer assembly and will run you over $30. So if you are just going to inspect the strainer, remove the whole assembly (petcock and strainer) from the tank and leave the big nut on.