Not starting!

[ABullock91]

I've got an '89, and this morning I went to crank her up to ride to school, and she won't take. She'll crank and crank and even put out some exhaust, but she won't stay running. The bike backfired this morning too, while still not starting.
She's got a full tank in her, and I just had the battery charged. She started fine yesterday.

Any ideas?

[catsalive]

My sister has a 91 and had a similar problem. The tap wasn't turned off last night and there was too much fuel and plenty of backfiring. She gave it more fuel by using choke and throttle which doesn't help when starting.I have some ideas, I apologise if you are familar with them/they sound patronising...

As you might know the backfiring is from too much fuel so it could be that the carbs are flooded to cause it to go that far.

Flooded carbs?
When carbs are flooding I get advised to put the fuel tap off and give it time to sort itself when there is flooding as time is the only fixer. Something else that can be done to help is to take off the spark plugs, heat the sparking point with a lighter and put them back as this helps the fuel to burn (somehow). Depends if they are all stuck behind the radiator tho. This time could simply mean 15 minutes not touching the bike with fuel tap off.

Faulty fuel tap / left on overnight?
I don't know what the fuel tap scenario is but if it is slightly faulty or left on overnight fuel could get through. This means it wouldn't all burn normally and pop! Wake everyone up at the early hour.

Worn/bent valve?
Maybe the full fuel tank is creating too much pressure on a valve putting too much fuel through which could mean a worn/bent valve somewhere letting it through as well. These older bikes have so many parts that may still be original but to be fair yours is 20 next year and they wear away.

There's my suggestions. Good on you having an 89 bike

Catsalive

[Drewski]

Is your bike locked up overnight? You sometimes get jokers swapping plug leads over and such hilarious japes

When's the last time the plugs were renewed? Might be worth taking one out after trying to start it again and seeing if fuel's getting through, check the spark while you're there too.

[Drewski]

My sister has a 91 and had a similar problem. The tap wasn't turned off last night and there was too much fuel and plenty of backfiring. She gave it more fuel by using choke and throttle which doesn't help when starting.I have some ideas, I apologise if you are familar with them/they sound patronising...

As you might know the backfiring is from too much fuel so it could be that the carbs are flooded to cause it to go that far.

Flooded carbs?
When carbs are flooding I get advised to put the fuel tap off and give it time to sort itself when there is flooding as time is the only fixer. Something else that can be done to help is to take off the spark plugs, heat the sparking point with a lighter and put them back as this helps the fuel to burn (somehow). Depends if they are all stuck behind the radiator tho. This time could simply mean 15 minutes not touching the bike with fuel tap off.

Faulty fuel tap / left on overnight?
I don't know what the fuel tap scenario is but if it is slightly faulty or left on overnight fuel could get through. This means it wouldn't all burn normally and pop! Wake everyone up at the early hour.

Worn/bent valve?
Maybe the full fuel tank is creating too much pressure on a valve putting too much fuel through which could mean a worn/bent valve somewhere letting it through as well. These older bikes have so many parts that may still be original but to be fair yours is 20 next year and they wear away.

There's my suggestions. Good on you having an 89 bike

Catsalive

Good idea heating the plugs, works well on my 2 strokes after they've been standing but you'll need more than a lighter, maybe a blowtorch or stick them on the stove for a couple of minutes.

The fuel system has a pump so it won't be the tap been left on

The part about the valve makes no sense whatsoever I'm afraid

[ABullock91]

Thanks for the input guys

She's locked up anytime I'm not riding.
I thought she might be flooded, but I didn't know about the fact that exhaust was still coming out, so I thought maybe that might mean it wasn't.

I haven't done anything to it since I've gotten it, I've been meaning to have it serviced, I just haven't had the money to do it. And I don't know anything about bikes, so I'm a bit nervous to try and service her myself.

[ABullock91]

Damn thing still won't start.

It makes me want to put a hole through every surface of the garage.

[Drewski]

Have you got the PDF version workshop manual? Theres a good troubleshooting guide at the back. We can tell you the same things, "check for spark", "check fuel is getting through", etc but it's a lot easier when it's printed off and in black and white in front of you. 9 times out of ten it's blocked carbs or worn plugs, once you know for vertain thet theres a spark and the fuel is getting through ok, you can start elsewhere.
                          I understand the frustration but sometimes you just need to step back and try a new approach.
                 let me know if you havn't got the manual and I'll mail you a copy.

[Drewski]

Oh, and get yerself a punch bag, those doors and cupboards can get expensive.

[ABullock91]

I haven't got the manual yet, I keep meaning to email that guy who posted a thread about it.

[Kai Ju]

Just a couple of suggestions. The stock CB1 comes with a fuel pump which should eliminate the flooding issue, even with the tap on.
Which brings me to my next point, have you drained any of the floatbowls yet ?
If not, do so and check how much fuel comes out. If it's hardly any you are either out of gas or your fuel pump is not working. Either way it won't start.
On mine I've eliminated the fuel pump and am running fuel straight from the tap to the carbs, have done so for the past 3000 miles with no problems.
Also after you've drained the floatbowls, turn the tap and key on and switch the engine stop switch ( kill switch ) off and on. This actuates the fuel pump and fills the float bowls with a rapid clicking sound that slows as the float bowls get full. If you don't hear that sound your pump's not working.
BTW, you did have the kill switch on while you were trying to start this bike ?

Kai Ju

[Drewski]

I haven't got the manual yet, I keep meaning to email that guy who posted a thread about it.

I've stuck a direct link for the manual on the thread

My fuel pump packed up too - if it is that, it's a fairly easy job to replace.

Kai Ju, how do you get yer bike to use the last half of the tank when gravity fed? I took my pump off to get the bike home when it went but had to have a full tank to work.

[Kai Ju]

Kai Ju, how do you get yer bike to use the last half of the tank when gravity fed? I took my pump off to get the bike home when it went but had to have a full tank to work.
[/quote]

Mind you I'm running F3 carbs on my bike but the lowest point of the fuel tank is still above the float level of the carbs, even on the stock CB-1.
I also installed an F3 fuel valve whose spigot runs straight forward towards the carbs and I wonder if that makes the difference. ( You have to flip the upper shock mount bolt around with the bolt head on the left so it clears the fuel line )
I haven't had any problems draining the tank past reserve and have filled it with as much as 2.9 gallons.

Kai Ju

[ABullock91]

How hard is it to find a fuel pump? I remember reading somewhere it was the same pump used on a few bikes.