Spark Plug Diagnosis

[crazdcanuk]

I intended to go on a ride today, unfortunatly my bike decided against the idea. The bike will idle and rev, though it doesn't sound right. When I do give it gas it will hesitate before it increases rpms. Before I messed with anything it wouldn't idle well and when I gave it any gas it would cut off.

I rode it around the block and noticed there was very little power (took a long time to get to 40mph).

There is new gas in the tank. I've checked fuel flow and it seems fine. Air filter is relatively clean and not blocked. Though there was oil type liquid in the air box. Initial pilot screw setting is stock.

I have a picture of a spark plug here (http://filebox.vt.edu/users/chmurph1/ss.JPG). I don't know how to read spark plugs. If anybody could help me out it would be appreciated.

My best guess is it's running very rich. I'm not sure whether the spark plug picture supports that or not. If it is running rich I don't know how to change that. So I'm stuck. I'm thinking about getting new plugs tomorrow since these are obviously fouled and seeing what happens.

Charlie

P.S. the bike is a 1992 Yamaha Seca II

[Wahooman]

How many miles on the plugs?

[crazdcanuk]

I'm not sure, I just bought the bike.

[RAGrote]

Oh man.. Terrible picture, but.....
Looks incredibly rich. Indication of clogged air passage. Too much fuel.
Weak spark, bad plugs, bad wires, bad rectifyer.

Replace plugs FIRST. Cheapest fix.
Clean/replace air filters.
I'd probably drain and refill the fuel tank as well.... just to be sure there's no water/junk.
Then, if that doesn't help, start diagnosing the spark system.

Good luck doood....

[crazdcanuk]

Yeah, the picture does suck. It was the best I could do with the camera I have.

I guess I won't be able to do much until Tuesday as it seems every shop in the area is closed Sun and Mon. And of course none of the auto parts store carry the plug I need. So much for riding this weekend.

Thanks for the input, hopefully I'll have her running again soon.

[crazdcanuk]

Well, I got new plugs today. After installing them I gave her a crank and she was up and running... for a moment. When started she immediately went to about 4k rpm and then fell back down and die. I wasn't able to start her again because my battery died soon there after.

I'm hoping we have a charger at my work as I'd like to avoid purchasing one at the moment.