Mercury XR2 150 *need help please*

[bandit66]

This motor is a mechanic's nightmare..... Well mine anyway.

Ok so long story short, I bought a used XR2. Everything is fine, except idle. It idle's too high. All carbs have been professionally "linked and synced". I know it's too lean, and it has .052 idle air jets. I have not been able to find a repair manual online to confirm factory jetting, but I have read it's .044 for the idle. I ordered a set of .050's for the idle air jets, hoping to rich it up a bit. Here's the kicker though:

*It's got the oil bypassed 50:1 premix
*It has an older intake - Does not have oil injection
*It has a marine electric fuel pump (inline)
*It runs great at WOT with .072 mains

Not an ideal scenario I know, but it's what I have to work with. Has anyone out there messed with these idle air jets? I can get it to idle down if I retard the timing, but it does not like it and eventually dies. I know by going from .052 > .050 it should in theory run richer at idle. Go the other way, and it would get more air causing it to go lean. Like I said, any feedback on this would be greatly appreciated.

Mod EDIT: Dead link removed

Part I am talking about is number 20.

 

[Chris1956]

Normally you retard the throttle cable (after backing off the idle stop screw) to lower the idle RPM. If she runs smooth, I would leave the jets alone.

 

[Chris1956]

And a mechanic would know that, I would think....

 

[bandit66]

You did not read my post. I would of thought a "Supreme Mariner" with over 20k posts would read posts...

 

[racerone]

?????---Did post # 1 make it clear ?----Is your motor a " nightmare " for your mechanic ?----Or is your motor a " nightmare " for you ?

 

[Dukedog]

don't let 'em get ya.. I understand what ya sayin'.. if ya can't get there with timin' and ya think idle jets are right then ya may have a leak some where and/or ya got a carb problem in tha idle circuit more than likely ... whats tha wh number on tha carbs? they may have been messed with already if you say its got 72's for mains.. I don't know of any 2.0 plain or xr2 with mains that big with production carbs.. it is a production xr2 and not high performance xr2 right?