Hello Atc300r
Thanks for the question unfortunately I only have a general answer. I understand from your question that you want to know when the t4 project was started not when the production model became available.
I don’t remember the exact dates but this is generally what happened. If this is more info then you were looking for then just disregard anything that isn’t pertinent to your question.
We received the original Japanese made t4 prototype at US Kawi R and D in 1986, around 6 months prior to the release of the 1987 production model. Due to the fact that the Japanese “version” and “vision” of an out of the box high performance recreational/racer quad fell far short of US Kawi’s criteria for one, the production release date was probably delayed by 30-60 days since I literally cut theirs in half with an air hack saw to modify it. The engineers from Japan were not amused however everyone in US Rand D thought it was pretty funny.
The planning and drawings for a totally new vehicle typically start approximately 1 ½-2 years in advance of a planned production release date with the exception of the Kawi Mule of which there was a working prototype around 1982 and was finally produced for 1987, lol. On the other hand the 84 t3 took around 1 year from start to prototype.
If I remember right, US Kawi was not even notified or aware that Kawi Japan was working on this particular project until around 30-60 days prior to the day we actually received it. We had discussed the idea of building one after I first saw Suzuki’s prototype or pre-production model prior to it’s original release however that’s the last time the topic came up until 86.
Hope this answers your question.