I recently just finished doing some work on my cbr 600f3 and made sure everything is set to its manual standards but the bike just does not want to start. below is a video of the bike trying to start. the bike has a fully charged battery and brand new spark plugs. i have cleaned the carbs and replaced the far right float bowl as the pin was stuck. i also had to take the cylinder head off to removed a broken exhaust stud but i made sure to follow the manual exactly as specified for torque and re-assembly. i did an oil and coolant change as well as also changing the chain tensioner with a brand new one.. but honestly i am not sure why the bike is just now not starting. is the chain tensioner bad? issue with the gas? engine? i am beyond clueless. it will stay idle sometimes for just a few seconds. if i hold down the ignition i can get it to rev but just dies after leaving on idle for more than a few seconds. there is also a clicking noise you can hear in the video. Any ideas would be extremely helpful.

 

Sounds to me like carburetor issues. If it starts up at all, then you have at least some fuel and spark. How did you clean the carbs? Did you do a complete soak? When reassembled, did you check the float bowl measurements? Sounds to me like it is starving for fuel.

 

Thank you for the reply. I didnt do a complete soak. when i was cleaning the carb all i did was removed the float bowls backing and than removes all the metal float bowl peices along with the plastic float and float pin and than began to spray carb cleaner all around the float bowl and also in the floats metal parts that i unscrewed and used air right after spraying with the carb cleaner. i than check all the metal peices making sure there was no clogs or gunk still inside and after i did that i screwed all the parts back in and than put back the plastic float with the float pin in all 4 float bowls and made sure they move correctly. after confirming that i screwed back on the bowls and set it up.

I should mention i did change 1 thing on the carb, the original owner before me had a air hose on the left side of the carburetor that lead straight to part #7 in the pic below. i looked at the manual of the cbr and realized thats all messed up so i put the water hoses to their correct places on the carburetor as the manual directed. (my was made after 96 so it has 3 water hoses) not sure if that change caused anything to change but it seemed pretty weird to have an air hose on that side of the carb.

 

Hi Nick.

In my experience, shooting carb cleaner and then high pressure air is often not enough for a gummed carbs. When I say soak, I mean to actually disassemble the carbs from each other, pulling all rubber/plastic parts (o-rings and everything including pulling the jets), then literally soaking in a bucket of carb cleaner (I use Berryman's Carb cleaner.. comes in a gallon can so I can soak each carburetor for 24 hours). Once a 24 hour soak is up, then I blow high pressure air through. I have worked on carbs so gummed that soaking jets overnight didn't do it and ended up replacing jets since it was just easier and less time consuming.

Just my opinion but it sounds just like bikes I have worked on with carb issues... in all those cases bikes sat for too long and old fuel gummed them to one degree or another and only a good deep soak did the trick.

I am wondering if the "air hose" is actually a vacuum line that is supposed to go to the fuel petcock that comes off the bottom of the tank? I would have to look at diagram for that but I know on the 98-99 CBR900RR's, there is no fuel pump and instead there is a vacuum line from carb to fuel petcock.... If I am not mistaken the F3's were the same way... they run fuel supply off a vacuum from the carburetors to the fuel petcock.

 

alright, i will try soaking them in carb cleaner. i know the bike ran great before i started cleaning the carbs so not sure if i just messed something up or not. and for the petcock, it just has a line that goes through a filter straight to a fuel pump assembly. i will have a picture of that below. i made sure all the gas hoses were cleaned and not clogged also as well as the fuel pump. looking at other f3's i dont see anyone having a hose hooked from that part of the air hose so i have no idea what thats all about but i will double check the fuel lines just to make sure they aren't tangled or knotted. and i will also check on the carbs and see what those look like. if i can i will take some pictures as well and keep the post updated

 

Hi Again Nick.

You say you have a fuel pump? What year is your F3? None of the years of F3 (1995 through 1998) I recall, nor have diagrams for ever showed, a fuel pump.... They were not manufactured with fuel pumps... they ran off vacuum line from carburetors to petcock. If you could post a picture of your carb assembly on the bike and the fuel pump you are referring to? That might help.

Partzilla has a ton of diagrams that might help you narrow it down as well as they have for all 4 years of the F3.

 

i was refering to part #1 in the diagram i posted in my last reply, my assembly is currently exactly as the diagram above shows. but i will post of pictures of my assembly as well later when i get the chance.

 

Hi Nick. Really weird but yes, the F3's do in fact have fuel pumps... I stand corrected and was going from memory... sorry and after I looked it up confirmed fuel pump was in that year and model.... teach me to try and go from memory (a fading memory at that LOL). Really odd too because my 900RR has no fuel pump by design in that same generation (98-99)... came from factory that way and haven't worked on an F3 in probably 10 years now, so apologize for getting off course.......but you put all the other hoses and things where they are supposed to go sounds like. The fact that it fires up initially then dies, still sounds like a fuel issue at least on the face of it..

I just watched the video you posted again (which I should have payed closer attention to).... I once had a fuel pump go bad and it clicked like that... made a racket and didn't send fuel... you could test the fuel pump with key on see if it pumps fuel into a catch bucket when it primes.... if it doesn't then you may have found your problem... if it does, then have to keep searching.

Are you absolutely certain you put the head back on with the correct alignment on the CCT? If the timing is off on those gears can cause terrible problems but without taking a look and going through and looking to see if the gears are properly aligned (pretty sure you have to make sure to align the EX on the exhaust cam with the IN mark on the Intake cam before you disassemble, this way the pistons are aligned to the cams/valvetrain when you put it all back together).

Just throwing out ideas here so feel free to eliminate them as you feel the need.

 

No worries at all it happens, and yes i was very worried and cautious when messing with the engine so i made extra certain that i followed the manual 100% when i was messing with that just to make sure i didn't mess anything up. i also made sure to use a proper torque wrench and torqued all bolts exactly to the proper torque spec as the manual stated. i aligned the T mark with the line on the cover and made sure both the in and ex lines were even with the cylinder head before tightening the bolts down for the cam shaft rods and i made sure to double check that the lines where still even before putting the head gasket back on. also applying correct torque to the head bolts as well. and i made sure to use proper grease on the valve caps before putting everything back together as well. Honestly i am no mechanic so im not quite sure if i did mess anything up, but i did spend quite a few hours just to double check my work. and i only messed with the cam shafts and the cylinder head. i didn't want to mess with the pistons or anything like that. just removed the cylinder head and cam shafts (so i could reach the cylinder head bolts) i than got the stuck bolt out, applied the moly grease stuff from the manual on the caps, applied proper torque to the cylinder head bolts (as well as dipped the bolts in oil as manual described) than re-aligned the cam shafts with the cylinder head and making sure the T mark was aligned also. than i screwed in the bolts for the cam shaft covers with proper torque following the manual ofc. and than placed the cylinder head cover back on with proper torque as well.

As for the fuel pump, i will check that as well just to make sure its pumping gas correctly.

 

Update: I just checked the fuel pump with the key turned and its not pumping gas at all. not even when hitting the ignition switch so i guess the fuel pump has broke while i was doing the repairs (my crappy luck i guess lol) but i will be ordering a new fuel pump friday and will keep the post updated just in case the fuel pump was not the main issue.