Strange Clicking

[sethward62]

Hello all, my name is Seth

Recently built my first motorized bike, a mountain bike with a 66cc engine. It has been working fine for 4 or 5 days, but just a few minutes ago it has been making a strange clicking sound whenever I start the engine/ or accelerate.
Its always rapid and methodical, and always the same length, which leads me to think it is mechanical. Any ideas?

Thanks in advance

 

[2door]

Check the fasteners at the exhaust manifold and the cylinder head bolts. Either one if loose or leaking can cause a 'clicking' noise. The torque on the exhaust nuts should be about 60 inch pounds. The cylinder head 120 to 150 inch pounds. Don't over tighten them.

By the way, welcome to the forum. We're glad you've joined us.

Let us know what you find.

Tom

 

[Patchy]

Did you do anything different before it started to make the noise? Does it make it when the bike idles?

 

[sethward62]

The only thing I did different was change the fuel mixture from 16:1(first tank ever) to 20:1.

But the problem has been solved. It was the fasteners on the exhaust. Had a problem with them the other day (rattled loose and my muffler popped off actually), and I tightened them down properly. Thanks a lot!