Again... its a matter of the heat present in the muffler system. a .20 engine is going to produce a dismal amount of smoke. A .61 can produce decent smoke. A .46 will be somewhere in between.

Also it hardr to find the different presure locations in the smaller engine to get proper smoke fluid flow.

The system can work... it can be either very easy to get it operating or very frustrating because you are dependant on muffler pressure to overcome muffler peressure.

the Macs mufflers that it recommends you use the smoke system with is appx $30 to $40. If you want to be able to depend on getting the correct fluid injection point... you'll get the muffler as well as the smoke plumbing kit.