Yes it is.


I wouldn't worry about the cost of the Merc HP gear lube. The front and back of the 177 hold about 8 ozs total. Using the Merc HP gear lube made it simple as I always had quart on hand anyway.

I've used Amsoil marine gear lube in
my 256's the last 5 years.

Synthetics have nothing to do with being too thin.

If the oil is too thin when it is new, you have chosen the wrong viscosity.

If the oil is too thin when used, it has sheared from too long of use, or perhaps fuel dilution, etc.

It is not too thin because it is a synthetic.

Ken

I agree, I don't know who there dreamed that up..weiand recomends synthetic 90w

I use dthe Merc lube out of convenience. I'm sure any of the lubes mentioned would work fine. Changing it often on the small 177 blower is what will keep it alive.

Royal Purple gear oil.