Topic: Cb550 cylinder not working HELP

[Emina1]

Hey guys Iam building a cafe racer and almost done. I started the engine for the first time today and noticed one of the pipes on the new exhaust hadn't turned brown with heat. I've checked the spark plug and it's working fine. Any suggestions?? Please note Iam very new to this so please be patient with me. Thanks in advance.

[strynboen]

thek fuel level in kaburettor...often the flots is stock..and you are running dry on that cylender

[teotdk]

All New sparks? Sparks can Fire outside the cylinder but mit inside when old..

[CB650CPastor]

If you have verified that you have spark, that leaves compression and fuel.

If your valve clearances are set, the most likely thing you're missing is fuel. You can verify this by checking the plug. If it's dry, you're not getting fuel to that cylinder. Check float height and float valve operation and make sure the jets are clear for the carburetor that feeds that cylinder. If the plug is wet, then you're getting fuel.

If you're sure you're getting a strong, properly-timed spark, and fuel, I would check the valves again and verify by checking compression in that cylinder. Just eliminate things one at a time and you'll get it.

[Vinhead1957]

It is either fuel spark or compression.  Fuel is next! Look at the plug for fuel and while it is out check compression

[calj737]

Fuel. On the bottom of the carb (you're #4 cylinder according to the picture) you need to open the screw and determine that fuel is present in that carb (have a drip can ready). If fuel is present, then likely the fuel height may be the problem. The easiest way to determine proper fuel height is with the "Clear Tube" method (see picture below).