96 vmax 600xt carb question help?

Hi guys im taking my carbs apart for a good cleaning. new needle & seat & float height check but noticed something very weird. Both carbs have a brass tube inserted into them right next two where the carb boot to the reeds goes. This tube is pointed slightly downward. & stops about the center of the carb bore. these brass tubes are connected via a t & goes directly to the oil pump.?? I have another set of carbs im told are from a 96xt they don't have the tubes. But interesting note these other carbs have small bosses on the outside as well & have a little dimple in the middle to start a drill bit? My 94 vmax 600 has the oil line going to the fuel pump. as does my v max 4. Now I would say this seems to be very well done so I don't think it was done by a backyard mechanic, so it think its factory but for this sled???? maybe something newer? good or bad. Maybe I should put the other carbs on? I would really appreciate any input. I mean any input. only other note is the machine has near 145 psi compression. maybe thinner head gasket by previous owner . other mods???
Thanks
Kevin

A direct oil injection kit.

Bender and others thought injecting oil into the fuel pump was a bad design and would create lean oil conditions when going to WOT after slower trail riding. So they came up with a direct oil injection kit for all models that injected oil into the fuel pumps. Many were sold and installed. That's what you have. The bosses they used to install the tubes are just a factory casting that could be used to install a carb sync port if required for the application.


Personally I maintain that Bender and everyone else who believes the "lean oil" myth is full of schnitt. If you understand how an oil injection system works their logic make no sense. There has also never been any proof that the design is flawed. Yamaha started this method of injection in 1983 with the Vmax 540 and used it on every liquid cooled 2 stroke they built after that with no design issues,,,, ever...


If it were my sled I'd put the oil injection back to the fuel pump and plug the ports installed into those carbs.

opsled

thanks Opsled.