Kawasaki 750 Brute Force, Fi, when you rev the bike it runs up to 1/2 to 3/4 throttle and then falls on its face, like it is starving for fuel. is there a filter or something I can check on the fuel rail, or could it be electronic, I am a certified ATV mech. through Honda.

SOURCE: engine runs, but it will not rev up past 2000-3000 rpms,

are you turning the choke off after its warmed up? most will not run with the choke on and warmed up.

also try running it with the gas cap open to see if you have a vent issue in your tank. if air can't get in, then gas can't flow.

if not a choke or vent issue, then try this. turn the petcock off and then disconnect the fuel lines one at a time going into the carb. start with carb fuel line #1 disconnected (and the rest connected) and in a coffee can, turn petcock on and ignition too. fuel pump should come on momentarily and inject some fuel. see how the quantity looks. reconnect the line to carb #1 and repeat for carbs #2 - #4. your looking for a decrease in fuel to a couple of cylinders.

if all looks fine, i would then focus on the carb floats & jets. have the carbs been off for a good cleaning lately? modern fuel breaks down quickly and could cause a gumming condition in the carbs. spraying the sea foam or carb cleaner into the carbs is bypassing the everything in the carb bowl (but it means the spark plugs are ok) so there could be an obstruction. i would look there first.

if uncomfortable removing the bank of carbs, you can try a quick fix first. with the petcock closed, open the drain screws of each carb and let the gas drain out. go and buy some yamaha carb cleaner (liquid in a black bottle) at a yamaha motorcycle dealer. mix it in a separate container with gas as recommended. close the drain screws on each carb. pour the mixture into each fuel line feeding the carb and let it sit overnight. DO NOT POUR THIS MIXTURE INTO YOUR TANK. its not a fuel additive, but a cleaner that will not harm orings or gaskets, but it will not ignite with a spark plug. open the drain screws the next morning and let the mixture pour out. reconnect the fuel lines to the carbs and test drive it.

if that didn't work, then removing the carbs for a good cleaning is my next step. good luck.

SOURCE: bike bogs for second then revs when throttling

Pull the slide out of the carb then remove the jet needle and move the clip one notch lower on the needle.

SOURCE: I need tuning specs for my 1982 suzuki gs 750.

You need to fix the fueling first - without fuel it won't run!
Your other problem sounds like an air leak - either the manifold or the carb. Check by spraying WD-40 or CRC at the manifold and carb join while the bike is running - if the revs change (either up or down) you have a leak.

mark woodring

• 498 Answers
• Posted on Jan 05, 2010

SOURCE: 2001 Honda Shadow ACE 750 idles, but won't rev up

vac leak craked boots

SOURCE: 2002 Kawasaki ZR-7S. wont rev up.

Check you main jets ccccccthey could need a good wiring through with needle wire cleaners or try running it without any air cleaner unit .If it runs well then could be an air filter problem.