Bike running like crap? Check the spark plugs first!

I recently purchased a 1986 Yamaha FZ600. Brought it home, put a new battery in, did an oil change, and fired her up...started right up (with the choke on). Now, since I'm a complete newbie to bikes... I had no idea how a 600 was supposed to behave. It was quick...but, not that quick. From what I've seen in videos... the throttle should have been much more responsive. I took the fairings off, and started poking around...

First thing I noticed, one spark plug wire was loose on the spark plug. Second thing, one of the plugs was only in hand tight and was not making a good ground because of this....so I was running on 2 frickin cylinders! Maybe 3 if the ground connected occasionally..... and finally, the park plug wires were in the wrong order!! I fixed that up and all I can say is WOW. The beast has been unleashed.

All the reading I did online said "clean your carbs", or "check for vacuum leaks", not one person mentioned "check your spark plugs". Maybe because it's so obvious....but, it was easy to overlook I guess since I did it! You live you learn, hopefully someone can learn from my experience!

Boy I think you would've noticed your bike running like crap on only two cylinders, especially when even the 80 year old grandma with the blue bouffant hair that can barley see over the steering wheel and driving her mint 1998 Buick Regal took you off the line:BLAA:! But seriously, glad to see you got it running good. Engine not running quite right, check fuel, spark, and air, probably in that order. Will fix it nine times out of ten.

I'm new. lol

Put some Seafoam and / or Chevron Tectron in the fuel tank.

It'll help clean out the fuel system and the top end of the engine too! Use it for a couple of tanks.

If you have access to a sync tool, I'll put money with all the mechanical issues you've had, the sync is off. On the carbed bike, simply adjusting (with a sync tool) the springs between each carb takes care of it...:thumbup:

Glad you got it fixed up so easily!

Just FYI, the FZ600 and 2004-2009 FZ6 are two completely different bikes. :thumbup:

This same thing happened to me with my Ninja 250r. Everyone told me to check my carbs but I decided to check the plugs first. Sure enough it was the plugs. Only 1 cylinder left, I would stall out if I tried to go above 12 MPH.