I cleaned and re-assembled the carburetor meticulously and tried to start it up again but there's no ignition.

It has plenty of power on it (new battery) and i can hear the starter engine turning away but it doesn't "fire".

Here is a video of the sound:
What are my options? I know that it can be a lot of different things, but then again, all i need is fuel, spark and some power.

The bike is registered in 1992 but has been rebuilt so the engine serial number is from 1999 (and all other parts I am told). Fairings are 1999 as well. It has been standing for 3 months before i bought it from a guy whom I trust.

I have been driving it for a month without trouble at all speeds and durations. When it died on me the last time I fired it sucessfully and had it running in idle for a minute or two upon which the RPM slowly declined until it died out (without me touching anything. Choke engaged). From this point on, I haven't been able to start it.

- I installed new spark plugs.
- I bought a new battery.
- I cleaned the carburetor.
- There's plenty of fuel. I start her with the petcock on reserve.
- The choke cable does engage fully on the carb.
- There's no leaks.

Thank you all for taking me this far. Coming from a person who didn't know what a carburetor was or looked like I've learned a lot about my bike and I find that's really something.

Quick Update:
I have been a bit perplexed concerning the Idle Jet (I am talking about the one that cannot be removed). See this thread: https://cbrforum.com/forum/cbr-600f3...vanced-104852/ and https://cbrforum.com/forum/cbr-1000f...ll-gas-104180/

I am almost certain that the guy who pokes the idle jet with the pin-needle is doing something wrong. As another guy in the thread says (and as were my experiences), it's impossible to poke a hole through the idle jet as shown, the hole is simply too small. I tried with the smallest of nylon guitar strings and i wasn't able to poke through it. It didn't look clogged since upon inspection the brass opening was simply too narrow. Of course I didn't test if it was clogged by blowing through it.

I really don't want to pull the carbs again to check whether it is clogged as I am almost certain that it is not clogged and that you're not supposed to be able to fit a pin needle (as shown) through that hole.

However, a clogged idle jet would perfectly explain my symptoms. What are your takes on this?

"RPM slowly declined until it died" That does sound like a carb (fuel feed) problem. Have you tried getting it to fire up with 'easy start' or something similar? If that doesn't get it running you will have to get the carbs off and check them again (check diaphragm's). You reconnected the vacuum line?

Hello again.

So it seems I've fixed the problem by cleaning the carburetors - however, if I in any way fiddle with the choke (turn it down halfway) or give it any throttle after starting it, it'll slowly decline in RPM and die out. And then it won't start again without a lot of battery power (i.e. I need a mechanic to assist me). I've bought a trickle charger, and will try if it works later tonight.

But for a week or so I've been starting it, on the choke without any troubles!

Could synchronizing the carburetors fix this problem? I need a special screwdriver to get to the mixture screws right? Or is there any shortcut?

For anyone looking at this thread who might have the same problem I can only support the advice given to me in this thread. Carefully clean and adjust the carburetor, it was the main culprit here. The battery needs to be fully charged and you need to be patient with the ignition as it might not fire up right away.

For the complete uninitiated such as myself, DO remember the idle speed knob on the left side of the motorcycle, freely accesbile through two plastic cover slits. This needs to be adjusted correctly. You want an idle speed of around 1050RPM's. Mine is at 1100-1200 currently but I haven't synchronized my carburetors yet. Many people, I am told, adjust the idle speed knob when the carburetor get's a bit dirty and so it can be difficult to start once you have it cleaned.

Thanks!

Did you follow the factory manuals procedure for bench setting the butterflies so that they open and close as closely as possible in relation to each other? That is important as well. Synchronizing the carbs will go a long way to ensuring smooth operation. when they are out of sync the cylinders will be fighting eachother. Another note is that when these bikes are cold, they don't like any throttle. so having it die out they way you describe makes sense. have you tried firing it on the chokes and letting it warm up before giving it gas? still seems like a fuel thing. When I did mine I noticed one of my plug boots would not stay clipped on the plug, you can check and verify your plug wires and boots are firmly in place

I re-read your post and had a couple more questions for you. Did you mess with the air/fuel screws? These control idle circuit fuel metering. if you removed them and then tightened them until they seated, that would be incorrect and would cause the bike not to idle at all. The correct procedure would be to lightly seat them then back them out 1.5 turns as a base, then tune according to the manual. For the inboard carbs I bought a really long flathead and can reach the fuel ratio screws just fine. When I rebuilt mine they still had the limiter caps on them. I had to remove them before being able to remove the air/fuel screws inorder to spray carb clean through those circuits. If yours had the limiter caps and you DID NOT remove the caps, meaning you did not remove the air/fuel screws, you might want to unfortunately consider pulling the carbs back out and doing that. They are a KEY component in the idle circuit and if not cleaned well and adjusted, will make the bike not want to idle at all, nor run with choke off, nor be very easy to start

I have been reading this thread and I give a huge round of applause to Apollon especially as he is on the street doing all this, it must be a bit of a nightmare.
Where are you fella ?

Hello again, sorry for my hiatus. Thank you for your responses and words of comfort.

My bike has been running.... just fine! No problems at all.

Man have I been happy about this bike riding around my little island (Zealand)! I'm learning something new every day - it really has a distinct character (like any bike I assume).

There's been no problem starting it since I pulled the carburetors and cleaned them. When its cold, it only starts on the choke - but that seems normal. I set the mixture screws in the same position as I found them and I haven't synchronized the carburetors yet but it runs just fine.

SM8898 - I don't think they had the limiter caps on. I need a long flathead.

I'll soon journey around Germany and Italy for a few weeks but I'm not worried about my bike as of now. It seems very reliable as is and I learned a lot so if things go wrong I'll probably be able to look into it myself.

Vroooom vrooom!

Attachment 88501