Blitz Posted July 10, 2012 Report Share Posted July 10, 2012 Been riding my bike fine for a month or so since I replaced the fuel pump. Rode it a day or so ago in the heat and it was bogging down at about 70 miles per hour. Doesn't matter where it's at in the RPM range....it seems like once it hits 70 miles per hour it starts bogging.Starts fine, idles fine, pulls normally through 1st, 2nd and the start of 3rd gear but the it hits a wall.....almost like it's on a speed limiter.Any ideas? I know it's fuel, air or spark. Just not sure which. My guess is either carbs need cleaned or it's not getting enough fuel at faster speeds or the plugs need changed. Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 10, 2012 Report Share Posted July 10, 2012 Check your clutch and kickstand interlock connections, maybe 70 mph is just enough wind to vibrate a loose connection and cause it to kill spark? After that I would give the carbs a thorough douching. My old fzr started bogging around 50 after I got it out of winter storage this spring. Turns out it wasn't the speed so much as the throttle position. Carb clean sorted it right out. Quote Link to comment Share on other sites More sharing options...
rawlins87 Posted July 10, 2012 Report Share Posted July 10, 2012 Carbs. Fuel filter cloggedmain jet issues or air/fuel adjustment screw Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 10, 2012 Report Share Posted July 10, 2012 More likely pilot circuit and slow jet circuit are clogged, main jets are for 3/4-wot. A/f mix screw is for idle. Quote Link to comment Share on other sites More sharing options...
Blitz Posted July 10, 2012 Author Report Share Posted July 10, 2012 I took the tank off to have a look around and it appears one of the hoses may have been crimped. I'm thinking maybe it was bent somewhat when I put the tank back on and with the heat while riding the other day, maybe it became malleable or pliable enough to almost completely kink, which would allow enough fuel to run but not enough when really accelerating. It's like it hits a wall in 4th gear at 9500 rpms......also has slow throttle response when I blip to downshift. I'll blip the first time and nothing happens and the second time I'll blip (immediately after the first) and it will blip like it should.I unkinked the partially kinked hose and placed some duct tape around it heavily to keep it from kinking and rearranged the hoses. I'm hoping that's it and will check tomorrow. If not my second solution is to run some seafoam through it. Hoping one of those two things will work. Third I'll probably change the plugs before I go messing with the carbs. I have some basic mechanical knowledge (I changed the clutch plates) but when it comes to carbs, my knowledge is lacking. Need to fix that actually.Thanks for the advice guys.....I'll let you know how it goes. Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 10, 2012 Report Share Posted July 10, 2012 Doubtful plugs are the problem. If your plugs were fouled it wouldn't even start. Carb cleaning is super easy, get on a ninja forum and I'll guarantee they have a step by step tech write up on how to do it. I use a muffin pan to keep all the pieces organized. You can always do one at a time so you can look at a complete unit if you forget how it goes back together. Quote Link to comment Share on other sites More sharing options...
YSR_Racer_99 Posted July 10, 2012 Report Share Posted July 10, 2012 More likely pilot circuit and slow jet circuit are clogged, main jets are for 3/4-wot. A/f mix screw is for idle.Once you twist the throttle and come onto the main jet, these are inconsequential. At 70mph, you're far enough into the revs that you're only on the main. Quote Link to comment Share on other sites More sharing options...
Blitz Posted July 10, 2012 Author Report Share Posted July 10, 2012 Solved.Took it out this morning and she ran like a freight train. The fuel line must have been kinked for a little while, progressively getting more kinked til she would fall flat on her face at 70mph. The heat was the most likely culprit.Thanks for the quick advice guys. Much appreciated. Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 10, 2012 Report Share Posted July 10, 2012 Once you twist the throttle and come onto the main jet, these are inconsequential. At 70mph, you're far enough into the revs that you're only on the main.Maybe if you're doing 70 in 3rd gear. In top gear at 70 my old 600 was at like 6k rpm with about 1/4 throttle. At 1/4 throttle you are using the pilots and maybe a little main but at such low throttle its your needle clip setting and your needle jet more than main. Revs don't matter when trouble shooting a carb, throttle position does Quote Link to comment Share on other sites More sharing options...
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