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1994 Johnson 140 bogging down and feeling gutless

S

SaltyScot

Regular Contributor
I got this V-4 (E140TLERR) a month ago and I've been battling with it since. It bogs down like it shutting off under acceleration and sometimes while cruising. Usually above 3500rpm, but sometimes less. Even when it behaves, it just seems to be running without much power. Will only push my 17' Larson to 42(tried several props) while my 1983 115 Mariner could get it to 46. It still has the VRO system connected. Here is what I've done.

Tried portable fuel tank and line
ohmed the coils
checked spark air gap past 1/2"
indexed flywheel and put a timing light on it at 2000-2500 rpm(looks spot on)
It has a new impeller
Tested VRO alarms
I've done more, I just can't remember at the moment(will edit)

could it be shift switch, fuel pump, power pack???

I noticed a couple times it didn't want to start when hot without holding in the primer key. I believe the seller mentioned that they rebuilt the carbs. I just texted him to verify. Motor likely sat for a few years. I bought it from a guy who lived at a campground. No, he's not homeless. He bought the whole dang campground right by a creek off of the Clackamas River. It's an impressive spread. All the out-buildings were converted into garages/shops/toy storage. It's like straight out of my dreams. Only neighbor is Squatch. ;) He has his own mechanic on payroll to keep his toys running. As far as seller's go, I felt pretty good about this one. But I only got to see it run on on a stand on muffs, so you never know unless it's on a boat on the water.

The VRO system seems to be functioning, but I'm wondering about the fuel pump. Any thoughts?
 
Here's a dumb question that shows how little I know about ignition timing:

Is the timing light supposed to fire right at the TDC mark? What about the spark timing advance sticker that's on the intake that says 18 BTDC? Shouldn't it fire 18 degrees before TDC?
 
Fact-----At full throttle the ignition timing is 18 BTDC------Where the timing is at smooth idle does NOT matter.----There is a timing spec for when throttle plates start to open.
 
"indexed flywheel and put a timing light on it at 2000-2500 rpm(looks spot on)"

I think I should clarify this from my first post. At that RPM, the light and my TDC marks were exactly in sync on each cylinder. It didn't flutter at all. Very steady. I'm using an inductive timing light. I've had it in my garage in it's package for about 5 years and never used it, or any other timing light. I know I need to set it at WOT, but I'm still studying ignition timing 101 before I attempt that. I've always worked on cars that had computer controlled timing. Except for the VW Bugs back in the 80s and 90s. We did those by sound. HAHAHA

Thanks for your help Racer!
 
I would also check the flywheel key.-----If sheared it will throw off the timing.----And before you say it or ask , you can not find a sheared key with a timing light !
 
So I tested the spark advance using the Joe Reeves method, after disconnecting the quick start first. It came out to 14 degrees BTDC, which seems right on since it's 18-4 per Joe. I guess that rules out the need to pull the flywheel?

While they were out, I checked the spark plug gaps. Not so good. #4 was correct at .030, but #1 and #3 were at .035 and #2 was .025. So I straightened those out. Also, they weren't the QL77J34 that's indicated for this motor. They were QL78YC. Not sure how much of a difference that makes.

I pulled the VRO pump apart and looked at its guts. I didn't really notice anything amiss, but I don't really know what I'm looking for either. I had just ordered and fuel pump for a 135hp Rude on a stand in my garage. So I slapped that in place of my VRO. I happened to find a bracket in my garage that worked without having to drill any holes in it or having to cut the fuel or pulse lines. So that was a pretty easy and easily undoable conversion. I disconnected the oil warning wiring plug. I still need to do the one from the tank.

So tomorrow morning I'll take it out and see what happens. I hope to report good news!
 
Well, I think had mixed results. It seems the bucking/bogging/miss is gone. But now I have a fuel starvation problem. I'll have to check my pump install. It may be a leak on the inlet. It started up and ran fine up to about 5000 rpm. And then it started to bog down and slowly run out of fuel. Pumped it back up and started it up again and same thing. I'll have to readdress my pump install. It seemed to run smoother at all rpms while it ran. It has the 438559 pump with the fitting for the pulse hose. I got an amazon one with good reviews for $20. Maybe I'll have to up for the Sierra or OMC one. Now I'm going camping and taking a break from this headache.
 
So I'm sitting at my campfire looking at the stock pics of my fuel pump on Amazon. (I'm not obsessed or anything.) And I think I may see the problem. My pump has the brass fitting for a pulse hose to connect as well as the hole in the back of the pump to pickup the pulse directly from the block. Well I didn't notice that and didn't block it off. So might be causing my fuel starvation. No?
 
If the hole is in fact open to the diaphragm it would be your issue.------Just can't trus these online places to get you the correct item.----Or send it back to them.
 
Much better now, but not quite perfect. I properly installed the fuel pump and put the proper plugs in there with the correct gap and that made a world of difference. It did buck a couple times in a half hour of testing. But it seemed to get better and faster as the time passed. Maybe just a good carb cleaning or rebuild should make it just right. But man, she is thirsty compared with my old 115 Mariner!:oops:

Thanks again Racer!
 
I did a SeaFoam treatment through it this weekend. When I pulled the bucket away, it look like someone had painted the leg black. EWW! Then I ran it this morning. It ran super smooth up to about 4000rpm and then gave me the usual issue. I'm assuming the high speed jets are clogged. Or maybe the new pump isn't up to snuff. But then again it had the same issues with the VRO pump before. Is it possible to clean out the high speed jets without removing the carbs? Looks like it's right behind the plug screw on the bowl in the schematic. Or is a full disassembly called for?
 
So I pulled the bowl plugs and cleaned the jets out. One seemed kind of dirty. However all of them were loosened up about 3-4 full turns. How big of a deal is that?
 
I went back and cleaned out the jets again and pulled a piece of caulking out of one. Like I can't even believe how it fit in there to begin with. I run a spin-on filter with an inline as well. So it must have been there for awhile. Otherwise, the carbs were super clean. I also put an OEM fuel pump on it and took it out on the river and same old bogging. It must be a coil or power pack only above about 4200 rpm. So I guess I will have to put the timing light on and run it up at that speed to see who's misbehaving.
 
Finally got it out on the water with the timing gun. Before that, I cleaned up all the grounds and replaced one coil because it had insulation and ground strap damage. Of course the water was too rough to put the light on it while running. I had to do it tied to the dock. Couldn't really tell much from that. The light didn't bounce at all up to around 4000. I didn't go beyond that. The boat actually ran ok up to 5500 for a minute before goofing off. Then it would bog down almost dying out before coming back to life. I am going to take apart the carbs and make sure there's nothing inside them before continuing. Can't afford fuel starvation. Then I'll probably just replace the other 3 coils and hope that does it. If not, then the power pack. Is there anything else I'm missing?
 
faztbullet said:
That single pump will not supply sufficient fuel to carbs..that the reason the VRO replacement is dual pumps
Click to expand...
If I wanted to add a second pump inline like the dual pumps, would I just tee the pulse hose to each pump? Since I just bought a new OEM pump, I'd like to use it of just getting the double pump.

I redid the fuel lines between the pump and tee, and the tee and fuel rail from 5/16" to 3/8". The tee to rail was an 'S' bend and I believe it was partially kinked. It's running a little better after doing this. In fact, every time I mess with it, it runs a little better. As in, less bogging and bucking. It only 'coughed' once in 20 minutes the last two times out. But I'm only achieving 4800-5000rpms with 21-19 pitch props. It's gotta do better than that. So just to be sure, I'm going to tear apart the carbs to make there's nothing in there. And I have a power pack on order as well. But I'm definitely curious about this double pump.
 
I think you nailed it Fazt! After rebuilding the carbs(they were spotless), I added another bracket and pump and plumbed it all together and it's running good now. No hiccups so far. I guess the original VRO was bad. Many thanks to you and Racer!
 

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Well I thought this was solved, but apparently not. Still having fuel issues above 4000 rpm. I'm finding that I can't even get the bulb to firm up completely. I've tried several bulbs and tanks. The in-floor tank and my 9 gallon will not prime up at all with any motor. I started out troubleshooting this problem with those two until I realized the problem. My 6 gal tanks will prime up fine with the 115 on my Tahiti, and give me no issues. But on my Larson with the 140 in question, won't firm up completely, and produce the above problem. I don't see a VS tank on this motor. What else can give me this kind of problem? I'm using 3/8" line from tank to the fuel rail. I believe my little tiny o-ring in the primer solenoid is leaking slightly when I pump the key. That shouldn't give me these problems should it? Am I putting too much stress on the fuel supply by running two pumps inline? Or does the demand from a large outboard expose unforeseen problems in the fuel system?
 
When I had an isse with the priming it turned out I put a tiny dint in the carb needle when I adjusted the float valve. The slightest indent or imperfection in the needle and seat will stop the valve from closing properly. Make sure there in 0 pressure on the needle and seat at all times. My needles had a rubber type coating which dinted easily and the new needles were metal.
 
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