Knocking at high RPMs

[Robertmyhtpc]

Hi all, thanks for having me!

i have my first build with an ebay 2 stroke. It is on a single speed Fixie.

I have had some issue with electrical. I lost the magnito and had to replace. My ongoing issue is though with a knocking at high rpm's. The engine always cranks right up. I have nice throttle response. What I get is a clanking and power loss at 3/4 to full throttle. It happens for 3/4 off the time. Occasionally, it will stop misbehaving and the engine is smooth and really produces power. The issue happened before the magnito change but seems to be worse now. Can it be the coil and if so, are there any suggestions on a replacement?


thanks in advance

 

[Deleted member 12676]

If it sounds better going uphill and worse going downhill then it is jetted too rich.
Put a truly adjustable carburetor on it.

 

[Fabian]

My ongoing issue is though with a knocking at high rpm's.

Maybe the issue is that you have over revved your engine and now it's become a problem that only money can fix.
These 2-stroke (66cc) motorized bicycle engines don't like to be revved over 5,000 rpm and you will extended engine life if keeping them below 4,500 rpm.

 

[Robertmyhtpc]

Suggestion for a carb

Gentlemen

can you suggest a carb for a stock engine?

Maybe the issue is that you have over revved your engine and now it's become a problem that only money can fix.
These 2-stroke (66cc) motorized bicycle engines don't like to be revved over 5,000 rpm and you will extended engine life if keeping them below 4,500 rpm.

 

[Fabian]

I'll send you a PM

Give the web pages time to load the photos.

 

[Deleted member 12676]

Mikuni VM 18mm
Dellorto PHBG 21mm
http://www.dragonfly75.com/jaguar/intakes.html