Fuel pump for 48 SPL Evinrude?

[papakevin]

Ok, I'm back and more confused than ever.<br /><br />Quick summary - Boat had idle problems, would stall when I put it into gear, but once going, it would run great over 1/2 throttle. Took it to a shop where they removed and cleaned both carbs, and drained tank claiming water was in it. Got the boat back, it still idles rough but doesn't stall when it goes into gear. Pulled both plug wires to verify both cylinders are running, and they are. Compression checked good - 125 each.<br /><br />Installed two new plugs, still idles rough. I've also notice a small amount of fuel in the lower engine housing, which I didn't understand because I couldn't find a leak anywhere in the hoses. <br /><br />I think the fuel may be coming from between my carb and my aircleaner... does this make any sense? I've been reading up on the fuel delivery system (thanks JD) and I'm wondering if the fuel pump may be adding too much fuel pressure at idle, causing it to run very rich and poorly. Has anyone heard of this before?<br /><br />Any Thoughts? Any easy tests I can do? J-D has been a great help thus far, but I'm always looking for more answers. <br /><br />All help is greatly appreciated.

 

[Loomis462]

Re: Fuel pump for 48 SPL Evinrude?

Dont mean to Hi-Jack this thread but I thought it was pretty weird that I just registered to post on these forums and saw someone had posted about an Evinrude 48 spl. Mine is a 1995 model hooked to a 1995 17ft Skiff. I took it out a couple days ago after moving my fuel tank from my center console, to the back of the boat. When I moved the tank, I bought a new fuel line and primer bulb hose to test the new location before I made it permanent. Here is my scenario. 1) got the the ramp, put the boat in and it took forever to get it cranked up. It usually cranks very easily, but this time it took a while, I figured from dry fuel line. 2) Once cranked i idled out of the no wake zone to the inlet and headed down the beach a few miles, ran like it always had, great. I stopped, made a turn satisfied with the new tank location and started to head back, got about halfway back and the motor started missing. It never totally lost power but kind of surged in and out and only ran a little over half of the usual WOT rpms (guess, no tach). Thinking maybe a defective fuel line, I moved the tank back to the old line and fired it back up, same thing surges in power. Ran back through the inlet to the waterway and played around with it and found out that if I choked the motor it would pick up and go for a few seconds, then die back down to lower rpms. If anyone could shed some light on what my problem might be I would be greatly appreciative.<br /><br />Dan

 

[Stumpknocker]

Re: Fuel pump for 48 SPL Evinrude?

Kevin, I own a 1995 48 SPL mounted on a 16 foot skiff. It isn't the greatest idler on the market, no two cylinder is really. But if you had the carbs redone properly as you suggest maybe the beast is just normal compared to say a 4 cylinder or some other engine you may be comparing it too. Is it stalling?<br /><br />I do know that the carbs do a bit of spitting (fuel) and may cause the fuel you detected in the engine cowling. When I cleaned my recently I too found some fuel/oil down there. Mostly residue, but fuel none the less. I don't think the fuel pump is your problem. I understand from Bombadier or however you spell it that when the carbs are rebuilt that the engine must be adjusted in the water and at a certain idle rpm. If this isn't done and say they do it on a hose instead the idle will never be as smooth as it can be. Mine was rebuilt that way and is somewhat rough on the low speed jets because of it. Still runs good, just not at idle speeds. It doesn't shut off however. Hope this helps.<br /><br />Loomis462, I would check your fuel pump. Maybe its just a coincidence that the problem started when you were changing your tank around. Also make sure that you have no air leaks since you have been removing fuel lines that were tight before. Actually I prefer to check those before bothering the fuel pump. That seems to be where you were altering things when it started.

 

[Loomis462]

Re: Fuel pump for 48 SPL Evinrude?

Thanks Gil009, I forgot to add in my initial post that my fuel pump only has about 15 total hours on it, 14.5 of those problem free. I doubt the fuel pump is the culprit. My thinking is now is that somehow some air is getting into the system. Thanks again and happy boating.

 

[papakevin]

Re: Fuel pump for 48 SPL Evinrude?

Thanks Gil for the info. I've heard various stories about how my 48 SPL should run. Some tell me smooth, other have said it's OK if it idles rough.<br /><br />Before it went into the shop, the motor did stall, but now it idles without quitting. At idle, it does "shake" a bit on the back of the boat (side-to-side), and it sounds like hell, but as I said, when you get it above 1/2 throttle, it runs good. <br /><br />I just ordered a factory manual specific to the year for my engine, so I may do an idle adjust in the water as you suggested and see if that helps.<br /><br />By the way, do you have a tach for your motor? Mine doesn't have one, and I need one BAD. My OMC controller has a plug connection, which I believe is for a tach, but I'm not 100% sure. <br /><br />If you or anyone has any recommendations on a tach, please let me know. Thanks.

 

[Stumpknocker]

Re: Fuel pump for 48 SPL Evinrude?

Kevin, your description of how your 48 runs is really a pretty fair description of mine too now that I think on it. At about 1/2 throttle planing out it gets much smoother. My engine runs great and it kicks a little side to side when at idle as well. This is probably a normal situation especially for a two cylinder model. <br /><br />As for a tach, the 48 didn't come with one or power trim. I ordered a digital tach from Tiny Tachs and hooked it up a year or so ago. It also has an hour meter built in. I can send you a digital photo of it mounted on the back of the plexiglass sheeting around the center console if you like. I spent around $40-50 bucks for it I think and the battery in it lasts about 5 years. Throw away after that. I really use it alot especially establishing WOT for props.

 

[seahorse5]

Re: Fuel pump for 48 SPL Evinrude?

The 48 and 50 hp motors are very critical on idle and linkage adjustments. Make sure the thermosstat warms up to about 140 degrees.<br /><br />If it has been run with a stuck open or missing thermostat, then the #2 piston may be scuffed on the bottom side, even though compression reads OK.

 

[papakevin]

Re: Fuel pump for 48 SPL Evinrude?

Thanks everyone.<br /><br />Gil, please email me the photos of the tiny tach and how you have it hooked up. My email is papakevin@gmail.com.<br /><br />Seahorse, I don't have any gauges with my boat (the SPL after the 48 SPL means it is a plain-jane engine). I'll check for a missing thermostat...<br /><br />Thanks.