Just bought this Honda for a great price. It is the 1500cc with the two speed Hondamatic and it ran great when I test drove it. Starts instantly and runs smooth....for a few minutes (Or about 30 seconds longer than my test drive was).

After a few minutes the transmission disengages (doesn't matter which "gear" it is in), engine revs but nothing to the wheels. Stop the engine, immediately restart and everything is fine...for a few minutes, then disengage, stop motor, restart and away....for a few minutes....and so on. Not bad in town but hell on the freeway .

Anybody have any theories about what is going on?

 

I'm not familiar with the older HondaMatics unfortunately, but it sounds like you might be losing pressure in one of the valve bodies once it heats up, which is why it's dropping out of gear.

That being said, there could be a MILLION reasons why it's doing this. I hate diag'ing automatic transmissions, they are incredibly complicated.

 

I assumed you've checked the simple things, like does it have enough fluid in there?