Did you ever solve this? Mines doing the same, it sat around awhile so I rebuilt the carbs (btw I rebuild carbs and work on vintage bikes for a living). I even completely separated mine, ran them through the sonic cleaner, etc. And it ran fine before so idk what’s up. I’ve pulled them off probably 20 times now and cannot find anything wrong. Jets and needles and all are original. Tried bandaid fixing it by up jetting and shimming needles, nothings working and we’re at a complete loss as to why. No vac leaks, new plugs, etc etc. pump seems to flow fine and petcock too. But it acts like a fueling issue, just no power under throttle and will even die out, but bowls are full of fuel and it’s not flooding neither. Like it’s ridable, just feels like half the power it should, bogging, and at 5k rpms will literally just slowly stall out like it’s ran out of fuel. Yet bowls are full. Tanks venting fine too, we’ve been round and round with this thing for months. I’ve rebuilt and tuned hundreds of carbs, but got no idea on this one. Starting to suspect spark advance or something of that nature
I never heard that before. I went back and listened to the video and I do here it clicking. Not sure why. Weird. Maybe i needed to switch the petcock to reserve. I only put a gallon of gas in it..
@@dannyhaigh472 no worries brother it was a good catch.. I am running into another issue. The bike starts and revs fine. But under load and WOT around 4-5K it bogs down. In thinking it's the air valve solenoid. The bike is 25 years old. I believe it has failed. I'm going to try and remove it and bypass it. And see if it cures my issue. Also ordered another new fuel filter. There was so much garbage in the tank when I got it running. Might be a little clogged..
@@munnday86 oh dude.. had exactly the same issue with my 1996.. these f3 always did have a bit of fluff in that Rev range but the 97 & 98 had ironed it out a bit, it's a pain in the arse. Do you know what throttle position it's worse in? Try a bypass and if that doesn't work take it to a dyno and they can diagnose if it's rich or lean then go from there! Mine was super rich from a massive main jet so rebuilt the carbs and put some smaller mains in. These aftermarket exhaust headers can cause havoc too..
@@dannyhaigh472 did you ever delete the air valve? I used what was in the all balls rebuild kit for the main jets. I believe the are .40 for the main jets. Has a k & N air filter and yoshimarua exhaust on it. Would I need bigger main jets. Mixture screws turned out 2.5 turns also.
Hey brother, good video, thanks for that. Quick question, what’s that third brass piece next to the two jets? Is there supposed to be a hole that goes through it?
I literally have the same year bike that i bought off a guy a year ago that im slowly rebuilding. That idle screw is supposed to have a spring that goes over the top of it that helps keep it from unscrewing itself.
Nice video… I’m restoring a 1997 CBR900 and your videos are really useful 😊
Can you send me the link to where you bought the carburetor repairs, please?
Did you ever solve this? Mines doing the same, it sat around awhile so I rebuilt the carbs (btw I rebuild carbs and work on vintage bikes for a living). I even completely separated mine, ran them through the sonic cleaner, etc. And it ran fine before so idk what’s up. I’ve pulled them off probably 20 times now and cannot find anything wrong. Jets and needles and all are original. Tried bandaid fixing it by up jetting and shimming needles, nothings working and we’re at a complete loss as to why. No vac leaks, new plugs, etc etc. pump seems to flow fine and petcock too. But it acts like a fueling issue, just no power under throttle and will even die out, but bowls are full of fuel and it’s not flooding neither. Like it’s ridable, just feels like half the power it should, bogging, and at 5k rpms will literally just slowly stall out like it’s ran out of fuel. Yet bowls are full. Tanks venting fine too, we’ve been round and round with this thing for months. I’ve rebuilt and tuned hundreds of carbs, but got no idea on this one. Starting to suspect spark advance or something of that nature
Yes I fixed 95% of the issue. I think the jets just have to be super clean. Any small amount of debris will make the bike run really bad.
I cant seem to get the needle out of the diaphragm assembly, i am afraid to put too much force into removing the back retainer thing.
Hey dude, I'm sure I can hear your fuel pump clicking fast like there's no fuel going to it.. is it hooked up to the tank in this video?
I never heard that before. I went back and listened to the video and I do here it clicking. Not sure why. Weird. Maybe i needed to switch the petcock to reserve. I only put a gallon of gas in it..
@@munnday86 Mate I do apologise, just seen the video you brought out after the diagnosis 😖.
@@dannyhaigh472 no worries brother it was a good catch.. I am running into another issue. The bike starts and revs fine. But under load and WOT around 4-5K it bogs down. In thinking it's the air valve solenoid. The bike is 25 years old. I believe it has failed. I'm going to try and remove it and bypass it. And see if it cures my issue. Also ordered another new fuel filter. There was so much garbage in the tank when I got it running. Might be a little clogged..
@@munnday86 oh dude.. had exactly the same issue with my 1996.. these f3 always did have a bit of fluff in that Rev range but the 97 & 98 had ironed it out a bit, it's a pain in the arse. Do you know what throttle position it's worse in? Try a bypass and if that doesn't work take it to a dyno and they can diagnose if it's rich or lean then go from there! Mine was super rich from a massive main jet so rebuilt the carbs and put some smaller mains in. These aftermarket exhaust headers can cause havoc too..
@@dannyhaigh472 did you ever delete the air valve? I used what was in the all balls rebuild kit for the main jets. I believe the are .40 for the main jets. Has a k & N air filter and yoshimarua exhaust on it. Would I need bigger main jets. Mixture screws turned out 2.5 turns also.
Hey brother, good video, thanks for that. Quick question, what’s that third brass piece next to the two jets? Is there supposed to be a hole that goes through it?
the bit i think your talking about is the choke circuit
Are you spraying the carbs with brake cleaner, or carb cleaner?
@@stefan-stocksmadesimple5241 carb cleaner.
I literally have the same year bike that i bought off a guy a year ago that im slowly rebuilding. That idle screw is supposed to have a spring that goes over the top of it that helps keep it from unscrewing itself.
Awesome. Yeah I dont know where the spring went. It must have came off when driving. Kinda vibrated off I think?
Nice work making progress! Ride safe!
Seems like your carburetor diaphragm return springs are too long