I decided to throw new spark plugs in the bike and nothing really changes except it seems like the bike wants to start for a second than nothing almost like a bike with the choke in on a cold start. You hear the rpms go up for a second then back to starter motor.

 

Just made an account to see if my solution can help you.

I bought an F3 few weeks ago and was running fine, started fine except when warm (still little odd when warm, need to add a little throttle on a warm start). It died at some lights and I thought it was fuel, I added fuel and had my brother bump start, worked fine for a week and suddenly at tesco starting from a warm start it wouldn't start. I heard it crank over a little and nothing, tried again and it sounded like it was just near death, no crank.

I had someone I trust look at it and he found out the regulating rectifier (as he called it) was over charging the battery and causing it to burn out, hence why it would be fine and then suddenly just die. Replaced both the regulator and put a new better quality battery on it and all is perfect now.

The only issue I have is on a warm start I have to use a little throttle, so for example stopping at the shop and coming back to start , it cranks over but won't start unless I use a little throttle.

 

So I'm guessing my ignition timing is off and I'm looking for help on how to set it back to stock. I can wrench but this is above my pay grade unless I get some help.

 

Ok guys ill try and give you what little advice I can as I'm not a mechanic/electrician .... iv done 3 years on HND in electronic engineering so I know my way around a screwdriver
Firstly try and read up (wikki is good ) on how CVK constant vacuum carbs work.
Now iv got a Kawasaki gpz500 parallel twin with 36mm CVK carbs which where a ****ing nightmare to get running right until I learned that there are different circuits inside the carb
pilot jet ,
main jet
,butterfly valve
, diaphragm and needle
choke circuit
only one pilot jet needs to be blocked to stop your bike working so when you say cleaned carbs ( I would recommend boiling all jets and brass fittings and carb bodies in lemon juice and water for 1 to 2 hours ) then using some guitar string or pipe cleaners make sure the jets are clear ..Next very Important get all 4 butterfly valves opening and closing at the same time (bench sync) you tube has loads of videos on this ..re install your carbs and fill the carbs with fuel before u attach the fuel pump hose that way you know the fuel is clean ....
electrical issues that will stop the bike from firing up
clutch switch
side stand switch
fob or imobilisor issues
fried battery or regulator?rectifier is intermitant
Always keep a written record of adjustments you made so if anything goes wrong u can simply go back and refer to the information .
NO1 rule AIR/FUEL/SPARK if its not running one of these is the issue

 

Even with me spraying ether in it still has nothing. I've got to be missing compression because after doing a bit of googling I found out the bike's ignition timing can't be changed but my my valves could be doing some wonky things which would explain the it not starting whether it be a stuck valve or the one of the cams jumping some teeth once upon a time. So I know how to get in to the valves and adjust them but not how to check if the have jumped a tooth, would be as easy as lining up the in and ex marks on the cams or am I messing more?

 

ill be honest I'm familiar with valves and cams BUT iv never dealt with shims like in the CBR600 . and yeah you can advance the timing but its normally done with Advancing woodruff KEY on my gpz500 +5 degrees .but the cbr advancer is at the pickup points next to the sprocket I think not sure .
Normally with valve timing the bike will backfire while trying to start if its the EX cams .cylinders 1 and 4 and .2 and 3 are the firing sequence .. have u put some oil into the cylinders before u installed the spark plugs ..prob the easiest to test would be clean the spark plugs re-install then try to run it for a few seconds then pull the spark plugs 1 by 1 the colour might indicate what is going on .MY CBR the prev owner had the coil wires backwards and the spark plugs on wrong cylinders once I sorted it and with choke on she fired up

 

The bike backfires good after 30-60 seconds of cranking, I've checked the spark plug wires again and again hoping that would be the problem but its still the same. I've even switched them up once just to be through.

 

here is my gpz500 you can hear the backfire that was due to IN cams on right cylinder too tight so maybe checking your valve clearance might shed some light

 

Alright so someone correct me if I'm wrong but it looks like I just set the motor to tdc and then I just have to align the 2 cams which have indexing marks are both. The in and ex have little marks on the gear that connects to the chain. I just have to set flat with the clyinder head. While I'm in there I will check valve's whose value i know is in the manual. Am I messing anything? Can I do this with motor in place or will I need to drop it?

 

I'll check my manual .
Tdc then the cam lobes should point upwards .cylinders 1 and 4
check the inlet cams first then exhaust cams .then rotate crankshaft so I can do 2 and 3 cylinders
.once u done that rotate the crankshaft before u tighten everything back up just to make sure nothings binding