2003 75hp Mercury/Tracker oil injection set-up

[Buzz_hagler]

Hello all. I am new to post to the IBoats forum, but use it frequently to help fix my problems...many thanks to all! I have not been able to find an answer to my latest issue. I bought a 2003 Tracker boat this year with a 75Hp Tracker (Mercury) 2-stroke outboard (OT771184). It had 100 hours on it. It had been run in salt water... some amount. I run it on fresh water only (MI). I have a feeling it was not maintained well by the original owner as I have found several small performance issues due to fuel and spark... nothing I couldn't fix. But here's the deal, she blows a lot of oil at low rpms, then has to burn it all out before going achieving WOT. I am sure someone has jacked with the oil injection pump link because of the damage to the ends of the link. It looks like someone put it in a vise with one end and pliers on the other....dummies. It seems they were trying to make it shorter to decrease the oil mix. They shortened as much as it will go. I can fix some of that by properly adjusting the clearance between the roller on the throttle arm and the actuation arm. Currently the gap is about 3/8".... spec is 0.005-0.020". I don't know how or why it got set so far away, but I can adjust it. This should help reduce the oil volume at idle, but now the linkage is no longer set to the proper length. So here's the problem. My oil injection pump arm does not have "tick" marks on it like many folks refer to. The arm has a notch/cut out about 1/4" wide. The pump has a post with a tick mark. What do I adjust this to? Nope, I don't have a service manual yet.... in the mail.

Your help will be appreciated.

 

[Buzz_hagler]

Re: 2003 75hp Mercury/Tracker oil injection set-up

Anyone out there with a newer model 2-stroke Merc 115, 90, 75, 50 hp with oil injection? Maybe someone could take a picture of their oil pump setting and send it to me? I would assume the tick mark on the pump housing lines up with the leading edge of the notch in the volume control arm... but I don't know for sure. Need some opinions......

 

[Buzz_hagler]

Re: 2003 75hp Mercury/Tracker oil injection set-up

Well, this is kinda crazy but I will answer my own question. I purchased a Mercury repair manual and found the proper setting for the oil injection pump arm. This has a type II oil pump (per the manual). The alignment mark on the pump lines up with the leading edge of the notch for proper oil flow at idle. It fixed my problems with burning excessive oil at idle, loading up, and fouling spark plugs. It runs like new. Hope this helps someone else out there.