Lifan 125 Semi Exhaust system Choices

[jaxpc]

I'm using a 1969 K1 frame with a semi 125 Lifan. What are my exhaust system choices with this engine/frame
combination? What companies should I look at and which of their complete exhaust parts packages will fit and work best? Thanks.

 

[dirtbkr188]

Personally, I like this one when using a bigger cc engine. It has the adjustable mounting strap for the slightly taller cylindered Chinese engines.

 

[jaxpc]

That one looks like it will work. How much bigger and where is the Lifan engine bigger than a 50cc stock engine? I don't have a
stock engine to compare with the Lifan. I assume the cylinder is longer/wider. Thanks for the recommendation.

 

[dirtbkr188]

The bigger cc Chinese engines will have either a 69mm or 78mm tall cylinder, depending on displacement and manufacturer. The stock Honda cylinder measures to be 63mm tall.

 

[jaxpc]

Is there some adjustment to the TB Performance Exhaust that you mentioned (other than the mounting strap) to fit the bigger Chinese
engines? (Like my Lifan 125cc semi auto) *Thank you for the Chinese cylinder measurements.

 

[dirtbkr188]

No other adjustments to make, just make sure you use a new exhaust gasket to get a good seal at the head.

A FWIW tip: install the muffler and strap in place (loosely) first, and then install the headpipe. Doing it that way helps hold the headpipe somewhat steady while you slide the flange into place and install the flange nuts to the head.

 

[jaxpc]

Sounds good. Thank you for the installation tips.

 

[MiniBike Mike’s Garage]

The stock Honda exhaust works well also, if you’re wanting to keep the bike stock looking.

 

[jaxpc]

Non stock is ok. I will go for a nice looking 28mm exhaust and silencer system that fits. Does the Lifan 125 semi engine take a different
size header gasket than for a stock engine?

 

[dirtbkr188]

No, the exhaust port is the same size as the stock engine.