1987 Mercruiser 3.0L

[labguy]

Hey guys,

A friend of mine has a 1987 Dynasty with a 3.0l Mercruiser. We took it out this past weekend and after doing a tune up and working out all the firing issues (new points, plugs, wires, etc..), it would run great at times and then bog down. We removed the carb fuel filter and it was full of trash. Ran great after that for a good while, then started acting up again. Sounds like the carb needs a good cleaning? What do you think? Also, it wants to run hot at idle. When you open it up, it cools down, but when you stop and idle, the temp runs up to almost 240. What are yalls thoughts?

 

[Bondo]

Re: 1987 Mercruiser 3.0L

We removed the carb fuel filter and it was full of trash. Ran great after that for a good while, then started acting up again.
Also, it wants to run hot at idle. When you open it up, it cools down, but when you stop and idle, the temp runs up to almost 240. What are yalls thoughts?

Ayuh,.... After running it with No fuel filter,... The Whole fuel system is now Suspect....

Also,.... Change the Impeller,.. It's Shot...

 

[labguy]

Re: 1987 Mercruiser 3.0L

Thanks for the info. Where is the impeller located? Is it a fairly easy fix? Im fairly mechanically inclined and would like to give it a shot myself.

 

[twostroke87]

Re: 1987 Mercruiser 3.0L

you have to split the drive apart to get to your impellor, there is a sticky posted that should give you a good idea of what to do.

Also, if the inline filter was full of garbage, take a fuel sample from the tank and see what it looks like, if its full of crap coming from the tank you will keep getting problems and will most likely have to drain your tank.

Also check to see if you have STEEL fuel lines or STAINLESS STEEL fuel lines, your problem could be old rusy steel lines and the inside of the line is rusting because you might have at some point had water in your fuel, or you have water in it now. Which is likely.