Hi all

When I picked up my cbr about 3 weeks ago, it was very hard to start. In fact, i could only get it going by bumpstarting it down hill.

When returning home, it started no problem. I started it every 2-3 days and it started after 5-6 seconds of cranking. Not great but ok.

It was sitting whilst I was moving for about 2 weeks and now it wont start again.

I have a spark (and did the first time it wouldnt start either)

It backfired a couple of times, coughed but thats it. I can see visible black smoke from the exhaust so im thinking its too rich to start and fouling the plugs. It does this with both the choke and without the choke.

Any ideas where to start?

 

I would start and investigate the fuel delivery system, since this tends to be where rich/lean symtpons stems.

Are you aware of the service history? Have you done any service since you got it? Start with the basics. Fuel filter, then I would investigate the carbs and make sure the fuel is being deliveried properly to the motor. Did it have bad gas in it? Did it sit for a long time with bad gas in it? You could have all sorts of issues with gas getting everywhere and anywhere it can.

 

You should always start the CBR1000F on the 'choke' in the mornings (first start). It is actually an enricher.

Check the battery is fully charged as that is another thing they like.

Also perhaps consider the alternator damper. This exhibits slow starting (although the starter spins over as normal) as a symptom.

Cheers, SB

 

Hi Alexander,
I'm going to join this thread as my baby has started to exhibit poor starting symptoms recently since the weather has got cold. I had the carbs off a few weeks ago and cleaned everything out. The problem went away for a while and she'd fire straight up on the button as expected but the slow start has come back again. The engine sometimes fires first time and then dies but after another one or two spins on the starter she fires up slowly and sounds like there's only two cylinders firing for a few seconds.
I'm convinced this is a fuel delivery problem but having cleaned from tank to carbs recently I'm a bit puzzled why the symptom has returned so quickly. Once it's warmed up it will tick over evenly and run fine at any speed.
If you find anything obvious while you're trying to figure out your problem please let me know. If I find anything I will post here.

Cheers

H

 

As a matter of course I would add an in-line fuel filter when cleaning the carbs, the petcock filters are very old now and may be damaged, letting crap from the tank through to your newly cleaned carbs.

 

Good point Hawk but I have an in line filter and also cleaned the carb filters too.
The petcock filter has been cleaned out so many times I've lost count due to the fact I bought a 23 Y/O bike with sod all mileage on it. Rust remnants just keep on coming. The trouble is, you can never be completely sure that tiny particles haven't made their way into your jets.

 

I know, but I'm thinking it's flooding with the choke on, that's the main reason for mentioning it.

I will keep in mind, but the starter spins over nice and fast.

You have described my problem to a T.

Mine does exactly the same. Initially it will cough, then cough a bit more, then start running on 2 then 3 then 4 cylinders.

Once it's HOT it restarts ok. If I leave it for more than 30 minutes or so it gets harder to start again, but doesn't exhibit the same scenario, when it eventually starts it starts on all 4

Unfortunately I have no history with it.

It say for about 3 months, but it currently has a fresh tank in it.

No servicing at all, it's all going to get done next week.

I may have the same problem. This would point to rust blocking the idle jets if the problem returned shortly after cleaning the carbs.

My bike has 88 thousand miles though.

 

When the weather is very cold, this is how I have to start her up (1990 FL, 56,000 miles):

Ignition on
Open choke fully
Press starter

Keep starter pressed while doing the following:
Close the choke
Open the choke
Close the choke
Open the choke
Close the choke
Eventually there will be a hint of starting with one brief splutter

Keep starter pressed while doing the following:
Close the choke
Open the choke
Close the choke
Open the choke
Close the choke
Eventually there will be another longer splutter

Keep starter pressed while doing the following:
Close the choke
Open the choke
Close the choke
Open the choke
Close the choke
Eventually there will be another even longer splutter

May have to repeat the above once or twice more!

At the long splutter, open choke fully and she will start

It's a matter of feel and awareness of your own bike. Wish it wasn't...

However, when the weather is not so cold she'll start on choke after about a second.

 

^ Bigger jets may help. Mine will spin a few seconds and fire up with bigger jets in. No lose of fuel economy that I can tell, with them.

 

Mine basically does this all the time.