Peter Chinn of Model Aircraft was unusually quick off the starting blocks. His report on the FROG 149 appeared in the same issue of the magazine in which the initial advertisement for the engine appeared namely April 1956. This makes it appear almost certain that the manufacturers had provided Chinn with his test example during the pre-release inventory build-up phase.

After describing the innovative and hence unfamiliar Vibramatic induction system in some detail Chinn proceeded to comment upon the engines performance. He found that the 149 started readily enough but seemed to like a generous prime. Running characteristics were similar to those of the 150 model. We would expect this given the underlying similarities of the two models apart from the induction system.

However Chinn commented upon an anomaly with respect to the engines response to the needle. He found that there was an appreciable time-lag between the making of a mixture adjustment and the manifestation of its effect on running. This was doubtless due in part to the unusually large volume of the inlet tract upon which comment was made earlier in this article. However other reed valve engines have shown similar tendencies so this characteristic almost certainly has something to do with the change in induction timing which will inevitably result from any change in engine speed - lacking any form of direct mechanical synchronization the system will require some time to re-stabilize. Regardless of the cause Chinn found it necessary to make adjustments in small increments and then to wait a few second to observe the effects.