What Next? '88 Evinrude 120 VRO

[capndan]

I am 4th owner of this boat, all in the family. I didn't pay much.

First owner (my uncle) got rid of the boat because it always ran poorly, and after maintenance, would run great until "we got out of sight of the marina, then would run like crap",

he gave it to my cousin who would be constantly changing plugs,...cousin gave it to his son who never ran it, I bought it cheap. Hull is great, and trailer is awesome... here's my story...



Last season ('10) was my first year with it. Just use it for fishing.

I started by having a mechanic check it out, because it hadn't been run in 4 or 5 seasons. He checked compression, said it was Ok, checked the water pump (OK) said there was oil in the carbs, changed the plugs, put some new gas in it (didn't drain the old gas- internal 30 gallon tank), suggested I run it.

It ran OK most of the year, but not great. It ran. top speed was only 28 MPH, (120HP on a 1200 lb aluminum Crestliner-should go faster, I know), and as
the season ran down, the boat got worse and worse. Probably put 10 hours on it.

In the off season we had the compression checked again-still good- and the carbs cleaned out, new plugs, and the mechanic said he wanted to replace something called "NLA Spark Advancement Link", but was told it's "No Longer Available"...

So he did the best he could with the existing part. He said it should run ok at WOT, might be a bit rough at low RPM, in fact he test drove it and that was exactly as it was.

I got it, it ran great for one day, then crapped out.

Back to the shop, he started from scratch, checked compression again, still good, but now found a bad Power Pack, changed it out, and added a Fuel-Water separator.

Ran great for about 5 trips (maybe 2 hours total) and ran like crap again.

I checked the fuel in the separator, and looked nice. No water or crud at all.

So we disconnected the internal tank and VRO, and premixed 50:1 and used an external tank. We changed out the plugs, which were already fouled after about 3 hours of total running.

It ran great. For about 5 minutes, then choked out, sputtered, and coughed and barely made it back to the dock.

We pulled the plugs, and they were fouled, and wet. Removed the carb cover, and the carbs were oozing milky fuel mixter, as if watered.

So....what next?

thanks,

CapnDan

 

[Haffiman]

Re: What Next? '88 Evinrude 120 VRO

Get rid of the water.
Pull the carbs and clean/rebuild with new gaskets.
Your 'missing link' you should be able to get from a salvage yard.
To me it looks like most of your problems might be related to air-leaks in the fuel system, or perhaps a sticking anti siphon valve in the fixed tank.
Do a good decarb of the engine after carb clean.

 

[capndan]

Re: What Next? '88 Evinrude 120 VRO

Thanks.

I have started a thread on replacing the tank, in the "boat restoration" forum. Or I may pull the tank and rehabilitate it, if I can.

I have a lot to learn on how the tank and lines and that whole system works. It seems to me I should move next towards getting
that done before anything else. Would you agree?

CapnDan

 

[Haffiman]

Re: What Next? '88 Evinrude 120 VRO

Running a 5 gal tank om a V4 might be a little too little.
Whatever you choose, use 3/8 lines and bulbs and try to avoid the quick connectors!!

 

[capndan]

Re: What Next? '88 Evinrude 120 VRO

I'm talking about removing and replacing or rehabbing the 30 gallon internal tank, and replacing all of the lines. My thinking is the
tank is 30 gallons, the lines and parts are all "pre-ethanol", the boat hasn't ever had very many hours on it, and sat some years
un-used.

So I'm thinking that there is probably a lot of water, sludge, varnish, etc. in that tank, or the hoses themselves may be deteriorating. Or a bad siphon, as you have suggested. I have read some threads on here that suggest that stuff may even not be discernible in the fuel-water separator..

So I'm wondering if I shouldn't just make sure that I'm getting clean, good gas into the motor before re-doing all of that carb work.

Even if I wind up bagging this motor and re-powering, I want to know I'm running clean gas. Anyway, that's my thinking.

I have contacted a salvage part dealer for the "missing link",,,no response yet.

Thanks for the input,

 

[Haffiman]

Re: What Next? '88 Evinrude 120 VRO

You may try a 'quick clean'.
A srpay can with carb cleaner.
Remove the drain plugs on both sides of each carb. Put the plastic tube on the can all the way in to it bottoms in the main jet and spray.
Cleaner should gush up in the center of the carb throats.
Flush out the carbs with fresh fuel before putting the plugs back.
Careful with fuel spill, disconnect battery first!!!
If lucky it works.

 

[jrdbrn]

Re: What Next? '88 Evinrude 120 VRO

My boat did this. I changed out the fuel line under the cover and put a high quality fuel filter. Fixed all my issues.

 

[archcycle]

Re: What Next? '88 Evinrude 120 VRO

Your issue where it runs good till it doesn't is pretty characteristic of a spark issue. I didn't see anything about a spark check in that book up there. If you don't have one, go down the the auto store and pick one up and test in the driveway. You want a strong hot blue spark at 3/8 gap. Then put it in the water and run it for a while and test again when it acts up. The ignition components behave differently when they get warmed up so you could be dropping a coil or two once they heat up. You could also pull the plug wires one at a time in the driveway when it's running well looking for one that has no effect (if any) and then do the same on the water after it starts to act up.

What is your max rpm when it's running well and what it's not?

I'm skeptical on the fuel issue (which it could certainly be) because sometimes it works well. It seems to me that if you had an air leak you'd have an air leak all the time not some of the time. If you had coils that were intermittently on their way out, you could have just this set of problems.