1987 135hp mariner carb/oil injection

[ambrjak]

I own a 1987 Mariner 135hp outboard. I had the motor rebuilt a few years back and had the oil injection removed so now I mix the fuel 50/1. I can remember the mechanic telling me that he had the motor set up to run rich for the break in period which is well over and the motor is loading up at idle and doesn't want to accelerate. Also smokes a lot. Once I do get it going, it runs great. The mechanic that rebuilt the motor is MIA and I need to get this thing running correctly. There are no adjustments on these carbs. I have had one mech tell me that the low idle jets need to be replaced? Has anyone removed oil injection and crossed this bridge?

Thanks, Ambrjak

 

[Chris1956]

Re: 1987 135hp mariner carb/oil injection

Fuel mix should be 50::1. You do not need to replace the idle jets, as they do not wear out. A leaking fuel pump diaghram will cause the motor to load up at idle and it can clear up as speed increases. Also carbs can flood, due to wear on inlet needle and seat. Rebuild fuel pump first. If that doesn't fix it, clean and rebuild carbs, with new gaskets, inlet needles and seats. Some of those motors have carb floats that are NLA, so be careful with yours.

 

[Faztbullet]

Re: 1987 135hp mariner carb/oil injection

Check the primary and secondary timing as it maybe retarded for break-in and this can cause it to load up.....

 

[ambrjak]

Re: 1987 135hp mariner carb/oil injection

Thanks for the quick response! I do remember the mechanic that rebuilt the motor telling me that he did something to it to make it run rich and needed to readjust it once the break in was over. I'm thinking that the timing might be it but now I need to get a manual so that I can check it. I will probably rebuild the fuel pump also. Are there kits available for that?

 

[Chris1956]

Re: 1987 135hp mariner carb/oil injection

Fuel Pump kits are avail at lots of web places. Try to get a Mercury Service Manual, not a third party one. They are much better. Timing is easy to set.

 

[Dukedog]

Re: 1987 135hp mariner carb/oil injection

No wonder your Mech. is mia......I'd start like Fb says. Idle timin' and chunk tha idle stabilizer if its still on it. If that don't do it then go ta tha fuel pump and/or carbs (shoulda been done with tha rebuild anyway)............jmo

 

[ambrjak]

Re: 1987 135hp mariner carb/oil injection

I had another mech look at the boat and the timing was way off in the primary and secondary. I have not picked it up yet but he told me that it is running great and is very responsive! I think may have fixed it. Thanks again for all the help!!