Honda305.com Forum

There's some very interesting info in there...... I had never heard of safety wiring the drive chain master link, thanks for posting it.

Sorry to hear about your problems, hope you feel better soon.
Your bike will be waiting for you when you're ready.

Now that you point that out Goody, I'm not sure.
An NGK spec page I found on-line lists the D range plugs as having 1.25mm thread pitch.

There are thread files available for dressing crossed threads like that.
The trick would be finding one for JIS threads.

I found a gas station with ethanol free gas here in New Orleans using http://www.pure-gas.org/index.jsp?stateprov after my fuel lines hardened and broke.
Fuel and cross over lines still flexible after about a year.

If you really want to be really shocked try listening to your engine with a stethoscope, Harbor Freight has a good cheap one with an extension probe. With a little practice it can help narrow down where the various noises are coming from but remember, most of what you hear is normal 305 engine noise...

I had a similar noise and it turned out my cam chain guide roller had come loose.
Your noise may be a loose cam chain, try adjusting it using the cam chain tensioner on the back of the cylinder under the carbs.