Hey everyone,

Just thought I'd update everyone here on my engine troubles.
I've been talking to guys over on Yamaha Motorcycle Forum for some tricks and trades and stuff like that.

I've just checked the timing and here are the photos with the results. Everything looks good.







Here's the youtube post of my bike on idle at full-choke.
Link: http://www.youtube.com/watch?v=m4kzcHbvWEU

The thought from others is that I have a hole in my piston or a messed up valve.
I might tackle the removing of the gas tank/ gauge cluster to get to the valve covers. I don't know about that project yet.

Does it need to be on full choke to run at all?

I am not a mechanic, but judging by the sound, I would take a look at the valves.

k_enn

No, doesn't need full choke.

I had a spark plug that was loose and I thought that might have been contributing or the cause. After tightening it I fired it back up with no choke.

Here's that video: http://www.youtube.com/watch?v=tX5iPLEiDLA

The Link to "no choke" does not work.

I know my engine sounds like crap if leave the choke on after it has started. It also sounds and runs like crap when it is running on only one cylinder. Can't tell if either could be contributing to the sound of yours, or not.

In any event, my suspicion as to why it stopped running right yesterday is a problem somewhere in either the fuel delivery to the cylinders or in the igniting of the fuel. I still tend to suspect valves due to the mechanical nature of the sound in the video when it is running on choke, but you might want to use the timing light (or a muti meter) to just check to make sure that the electricity is getting to both cylinders. Also, have you checked the gap on the plugs? That is a quick investigation.

k_enn

Last video didn't load for me, but it doesn't matter since I have no sound at work anyway. I'll check them when I get home.

The last video might still be processing. Youtube always gets slower later in the afternoon and evening.

I think I'm not doing anything else for tonight, just need to relax before a I get too ahead of myself.

It is hard to tell just from the sound. It sounds to me like you might not be getting full power from both cylinders, but it is hard to tell from the clip and it hard to tell why. I definitely hear a sharp metallic clank which varies with the engine speed. I would still focus on the valve train. I just cannot be more specific as I don't know that engine (e.g., if it had a balancer shaft, I would look at that too).

Hope you get it worked out.

k_enn

It almost sounds like one of his header pipes is loose giving no backpressure.

Well, initial diagnosis is a blown cylinder connecting rod. They have to put a litlte more time into actually seeing the problem.

If it's broken in the top part it won't be as bad, if the bottom part is busted they'll have to split the whole case and go from there.

A lots going through my head right now. I'll have a better opinion on cost on Tuesday or Wednesday when they'll give me full estimate for all parts and labor.

ugh.