A merc manual should tell you how to check the oil injection system!

"Dave" wrote in message
oups.com...
I have an 18' 1989 Sea Ray with a 135hp Mariner (Merc) that has not
been putting out the horsepower that it used to. It really bogs under
load (pulling a skier), where it used to do fine. Just can't get the
RPM's up, can't quite get the old top end speed, etc. I've had the
compression checked, it's OK. Plugs have been replaced, been through
dozens of tanks of fuel, drainded the carbs, had it checked by a shop
with no problems found.

My latest thinking is that may be this all started when I had the oil
pump replaced after it stuck *open* (lucky me! - too much oil). I've
read all the stuff about the pro's and cons of this oil injection
system, and would prefer not to disable it.

I am wondering how I can tell what kind of mixture I'm getting at high
RPM's or at least how do I tell if this things adjusted correctly? It
seems that the throttle linkage increases the oil delivery as the
throttle is opened. The rotating valve(?) on the oil pump is adjusted
so it's never pinned all the way open or closed. It's partly open with
no throttle, and it's more open at full throttle, but not completely
open. Any chance I'm getting too much oil at full throttle? Any ideas
how to check the adjustement?

Thanks in advance!!

Dave - Fremont CA