Topic: [New To Forum] Bike Doesn't Run (surprised?)

[campbmic]

Hi All!

I've been searching around the internet trying to find a forum dedicated to the old Honda CB's and this seems like the right match. I just recently bought a 1975 Honda CB 550 for $250. The bike turns over and sounds very smooth turning over. However, it just won't fire up! I cleaned out the tank, the carbs, and the fuel lines and replaced the spark plugs. I then took one of the wires off the plug and couldn't see a spark jumping from the wire to the plug. I'm guessing thats the problem, I don't know anything about spark plugs and was wondering if anyone had some advice.

I do have the shop manual. Also, if I want to make sure that gas is flowing into the cylinder how can I do that?

Thanks for any help!

P.S. the run switch and starter button are completely destroyed on the bike so I am making it turn over by connecting two terminals on the right side under the seat

[Ogri]

If the 'run switch' is destroyed you might need to fix that. If the right hand switchgear (which also houses the throttle) is the same as my CB750, you need to connect the black wire to the black and white wire. That will allow power to reach the ignition coils (under the gas tank.) Or, you could use a jumper wire to take power directly from the battery's positive terminal to the double connector attached to the black and white wires coming out of the coils.

You might have a bad spark plug, so to be sure, unscrew the spark plug cap so you have bared the end of the thick black HT cable. Hold that close to the cylinder head and see if a spark jumps. If it does, either the plug cap or the spark plug is no good.

The easiest way of making sure fuel is getting into the cylinders is to inspect the spark plug immediately after turning the engine over 5- 10 times with the throttle 1/4 open. The electrode should be wet/damp with gasoline.

Are you using fresh gasoline or the old stuff ? Refill with fresh.

If you take the fuel hose off the petcock (with it in the 'ON' position) does fuel rush out ?

[campbmic]

Well Im definatly thinking it has something to do with the kill switch. I just tested the black wire that splits into two black and white wires that go into the coils and it doesnt have any power.

When the key is in the ignition position shouldn't they all have 12v constantly running in them? Or do they not get power until you press the start button?

Thanks for your help btw!

[campbmic]

Hey Ogri thanks for your help!

I just went outside and connected a direct wire from the positive side of the 12v battery to the black and white wires coming out of the coils and it fired right up! Thanks so much for your help!

I still have a TON of work to do but I am VERY happy about this!!! 

[Ogri]

Another satisfied customer! I'm glad it's running too - great result.

Post a pic of it if you can, it can't be any worse than my heap of sh*t.