# 1981 Evinrude 9.9hp 2str starts but won't run



## CarbonSink62 (Sep 29, 2011)

Disclaimer: This engine came with Zen Again and I already wish I'd just left it there instead of 'investing' time and money in it, but here we are.

I rebuilt the carb (Yay, me!) and it starts on full choke, but dies before I can pat myself on the back (Boo, reality!). The only way I've found to get to run again is to wait about 2 hours and then I get another 8-10 seconds of operation.

Once it starts, if I get onto the choke right away, I can go to half choke and prolong the run to maybe 20-30 seconds. Then it dies.

I have replaced the water pump, plugs and wires.
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I have 2 thoughts:

1. Fuel pump - I'm guessing that the pressure I put with the bulb sees the engine through start up, but the run can't continue without more fuel and the pump isn't working. I've tried to keep pumping the bulb while runs, but it did not help.

2. Rich/lean mix - This engine has a needle valve that is labelled rich/lean; the rebuild instructions said to seat it gently and then back it out one full turn. The starting instructions say to set the dial to the middle. The dial is on the knob; the knob is not keyed to the shaft of the needle valve. So the valve is still one turn back from seated.
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Other observations:

The START position on the throttle is one step below FAST, but initial operation is very quiet. It purrs, it doesn't roar. In my experience with other engines starting on full choke, the engine screams until you get to half choke and drop the throttle a little. That leads me to suspect the rich/lean setting.

The throttle itself is very puzzling, the twist grip moves a couple of linkages one of which eventually pushes a cam follower on the carb and opens the butterfly valve to allow more fuel/air mixture into the intake manifold. This follower is only activated when the throttle is all the way to FAST; on START and below (SHIFT and SLOW are the other labels) the cam follower is untouched. So some other mechanism must be controlling engine speed below FAST, but I can't see what it is. I haven't ruled out the possibility that I reassembled the cam follower linkage wrong, but I can't see how.


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## dabnis (Jul 29, 2007)

When rebuilding the carb you may have missed some very small debris in the air/fuel passages. On the many outboards and motorcycles, both 2 & 4 stroke that I have had, about the leanest low speed needle adjustment was 1-1/2 turns out. Suggest you try it there for starters, maybe going richer until it starts to stumble a little then back in just until it smooths out a little. If it is not a mixture problem there is likely an obstruction from the tank forward. I had the same motor but can't remember the linkage set up. A good shop manual should show the proper set up. Maybe the float is stuck shut or not adjusted properly? I had a carb on a Honda 2HP that got plugged up. I cleaned out but it never ran perfectly until I gave up and put a new carb on it. Let us know what you find.

All of this assumes you are getting a nice fat bright blue or white spark when grounding the plug out of the motor?and pulling it over.

Paul T


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## Sea Dawg (Jun 26, 2012)

The fuel pump fills the carb bowl, but vacuum thru piston operation draws it into the reeds. Thus I'm thinking if it's the fuel pump would take more than a few seconds to empty the carb bowl . It should continue running if you pump the hose bulb even if fuel pump is bad. Since it's running initially continue to focus on the fuel system. The hose is often suspect as there are orings that leak, check valves that stick, or crack in the hose or bulb. The fuel delivery to the carb is suspect, if when the engine falters a quick shot of starting fluid will carry it a few more seconds.

Take the spark plug out right after it shuts down and see is it dry? On mine, that revealed tiny water drops on the piston which were from leaking by the head gasket. No other symptom other than I could start it but wouldn't keep it running. It also occurred right after replacing water pump so maybe the higher pressure brought on the water leak. This isn't perfect troubleshooting but maybe will keep you going today.

The engine speed below the point of cam roller moving the butterfly is controlled by rotation of the magneto plate which advances the spark timing.


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## dabnis (Jul 29, 2007)

Zen,

Forgot to ask, did the motor ever run properly? If so,was there any work done on it afterwards? Assuming you have good spark and it is timed properly you might try another tank, and fuel line from tank to motor. You could also try gravity feed directly to the carb through a separate line. If none of that works it may very well be the carb which could be re-cleaned and blown out with compressed air. Or you could just gamble on a new one? As mentioned above if the plug is dry after the initially firing it is likely starving for fuel. My guess is that if the motor sat for a long time without having the carb drained the carb was/is pluggrd up?

Pasul T


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## bubb2 (Nov 9, 2002)

fuel filter; it's a screen type filter lower than the carb on the right front of the engine. black box with a screw in the middle. Clean it.


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## CarbonSink62 (Sep 29, 2011)

Thanks, guys.

I've been jumping around (doing things out of order) and did not clear out the fuel line before installing the rebuilt carb, so I might have sent crap into the newly cleaned carb. I'll be tearing it apart again to check if I can't get it running soon.

I replaced the wires and plugs 'just because'; the next time I start it, I'll pull the plugs and look at them immediately post mortem. I'll check for spark then, too. I've read that it should jump a 3/8" gap. I gapped the plugs when I installed them.

A shot of ether after it dies does not bring it back, only time will fix it. That says 'flooded engine' to me, but I write software and have very delicate hands. 

I bought a new tank and fuel line so all that should be 'ok'.

BTW - I have never seen this engine run, the dealer said it was 'tank tested' by them; I'm ready to call BS on that.


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## CarbonSink62 (Sep 29, 2011)

bubb2 said:


> fuel filter; it's a screen type filter lower than the carb on the right front of the engine. black box with a screw in the middle. Clean it.


Did that, thanks. There was some crap in one corner, but it was clean enough (not fouled) to supply fuel.

Ken


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## tommays (Sep 9, 2008)

1981 is OLD for a fuel pump and all the dirt in the fuel has to pass through the TINY check valves in the fuel pump 

The KIT does not cost much BUT is a bit of a PITA compared to droping in a new ORGINAL fuel pump as you have to beware of knockoff spare parts


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## travlin-easy (Dec 24, 2010)

I'm guessing with this one, but almost positive that you failed to set the carburetor float properly. The setting is critical, and in some of the old rebuild kits they supplied a float gauge. You only have to off a fraction of an inch and the engine will either flood, or starve for fuel.

Good Luck,

Gary


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## CarbonSink62 (Sep 29, 2011)

The kit didn't have a gauge, but the procedure did show one.

I 'eyeballed it' for side-to-side and measured the drop with a ruler. I could have screwed it up.

If I order a new fuel pump, I'll put a gauge in the cart as well.

I'm buying a new 4 stroke before the end of the season, I need to get this one running so I can sell it; it would be nice if I could use it to cruise the river. I don't think I'll ever trust it enough to go play down by the the drawbridge.


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## CarbonSink62 (Sep 29, 2011)

tommays said:


> 1981 is OLD for a fuel pump and all the dirt in the fuel has to pass through the TINY check valves in the fuel pump
> 
> The KIT does not cost much BUT is a bit of a PITA compared to droping in a new ORGINAL fuel pump as you have to beware of knockoff spare parts


New (OEM) pump is only $47.

If I disconnect the line going into the carb and turn the engine over, fuel should come out of the line. That would prove the pump works, correct?

As long as I have a lit cigarette carelessly dangling from the corner of my mouth, it should be perfectly safe. 

Now that we're on page 2 and all the girls have stopped following the thread, does anyone know any good porn sites? :laugher


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## dabnis (Jul 29, 2007)

"A shot of ether after it dies does not bring it back, only time will fix it. That says 'flooded engine' to me, but I write software and have very delicate hands."

A plug reading should tell the story. If it is black and wet it is likely flooding and fouling the plug. Does a new plug help at all? If it is dry it is likely not enough fuel is being delivered. If it runs at all the spark is probably OK. I think solid state ignitions either work or not, not much in between?

I had the same motor, 15HP, bigger carb, I think, for 10 years. Many, many hours of hard running for hours on end. Treated it to new plugs once a year, changed the gear oil once in a while and that was it. It was still running perfectly when I sold the boat. Assumming the compression and seals are OK your motor should be OK, once you get the bugs out.

Paul T


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## CarbonSink62 (Sep 29, 2011)

Thanks, Paul.

I was ready to use it as an anchor when I first bought the boat; then I read about how dependable these motors are and decided to fix it up; now I'm ready to deep six it again;

I have a few more things to try thanks to this thread; I'll keep everyone posted.

Ken


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## tommays (Sep 9, 2008)

Best smoothest motor ever made so UNLESS its really screwed there is now place to go BUT downhill in quality


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## CarbonSink62 (Sep 29, 2011)

I agree it runs very smoothly, but only for 10-15 seconds at a time! :laugher


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## jassprag (Nov 6, 2010)

replace the coil or coils.


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## Jetexas (Apr 3, 2012)

My first guess is the vent on the fuel tank isn't open.

However, if it's flooding, not starving, I would second the float level diagnosis.


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## CarbonSink62 (Sep 29, 2011)

*Now it starts and runs but won't idle*

Huge progress today:

I advanced the rich/lean valve 1/4 turn toward RICH;

I finally understand the throttle linkage and it wasn't engaging the cam on the carb throttle at all; I turned the set screw all the way in and now the linkage just hits it when the throttle is at SLOW. When at START, the throttle is open about 1/4 turn.

At FULL choke it took off like a rocket and I was immediately decreasing the choke and throttle, more like I expected.

The water pump pees nicely and it ran at half throttle for over 10 minutes, so an awful lot of stuff has been qualified.

It won't idle, however. As I walk the throttle down, the engine eventually stalls before the linkage disengages the cam. I'm not sure what idle RPM is and have no way to measure it. It 'seems' like at idle the throttle linkage fully disengages the cam and the carb should maintain the idle on its own.

On a lot of carbs I've seen, there is a set screw the stops the throttle arm just before it hits bottom. There is no such arrangement here.

So, I'm looking at 2 options:

1. Tweak lean/rich (and troubleshoot) to get it to idle with the cam follower completely disengaged.

2. Find out why the throttle linkage disengages the cam so early.


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## dabnis (Jul 29, 2007)

I can't quite remember the cam follower arrangement but I think there was a mark that was supposed to lign up with the cam at idle speed? A good shop manual should show it. Suggest you get it running again and richen it up (counter clockwise) until it stumbles then lean it just enough to smooth it out, no more. Generally there is also an idle speed screw which is seperate from the mixture screw. On that motor it may be part of the cam linkage setup? Properly set up it should idle down fairly slow. Again, a good shop manual should help. Keep us posted

Paul T


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## CarbonSink62 (Sep 29, 2011)

Thank you, Paul.

There is a mark on the cam follower, I wondered what it was.

I'll set the throttle there and see how well it runs.

Ken


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## dabnis (Jul 29, 2007)

Curiosity got the best of me. From a Google search:

"Timing : The throttle cam plate that rotates under the flywheel when you twist the twist grip & the plate has an raised line type mark on the front of it. This mark needs to be timed so that when you advance the throttle twist grip, that the carburetor roller is at this mark when the carburetor throttle shaft just STARTS to turn open . To adjust this on the older motors, you loosen the 2 bolts on the RH side of the plate & adjust the cam plate to where it just aligns with the roller at the same exact time that the throttle plate begins to rotate. CLICK HERE for a link to the carburetor/fuel pump section for more detailed information."

Here is the link: Maintaining Johnson/Evinrude 9.9 part 1

Scroll down about 1/4 of the way, "Timing"

Paul T


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## CarbonSink62 (Sep 29, 2011)

Thanks for that link. I had found 'Leeroys Ramblings' months ago, but when I tried to go back the link was dead. Tons of good stuff there.

The motor has now started 3 out of 3 tries and it will be put on the boat this weekend. I can wring out these last few problems there. My boat might even leave the mooring and putt-putt up the river; I'm pretty excited. I wouldn't trust this motor to go down river where the drawbridge is waiting... hungrily. By the end of September, I should have a new 4 stroke motor and I can sell this Evinrude.

So, I will look into the alignment of the follower plate vs. throttle position. As it is I have to be very careful to only reduce the throttle so much and no more or the motor will stall. I need to be able to slam it to SLOW and not worry; I can't have it die in the middle of docking.

Ken


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## dabnis (Jul 29, 2007)

CarbonSink62 said:


> Thanks for that link. I had found 'Leeroys Ramblings' months ago, but when I tried to go back the link was dead. Tons of good stuff there.
> 
> The motor has now started 3 out of 3 tries and it will be put on the boat this weekend. I can wring out these last few problems there. My boat might even leave the mooring and putt-putt up the river; I'm pretty excited. I wouldn't trust this motor to go down river where the drawbridge is waiting... hungrily. By the end of September, I should have a new 4 stroke motor and I can sell this Evinrude.
> 
> ...


Thanks for the feedback. Sounds like you have a little fine tuning to do. Maybe give it a good run while still tied to the dock so the bridge doesn't get you. Assuming the ignition timing is OK, (there may be marks that a timing light will show), and there are no air leaks, and the idle mixture is as rich as you can get it without stumbling, it should idle down from 500 to 750 RPM (I think) If you need more than 2 turns out or it idles unevenly you may have an air leak somewhere. Anyway, I hope it goes well. Once you get it running properly it should last a long time. Mine ran perfectly for 10 years and was still going strong when I sold the boat. You might not need a big fat heavy 4 stroke after all.

Paul T


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## CarbonSink62 (Sep 29, 2011)

I adjusted the lean/rich setting a little richer and it now runs much smoother and restarts easily. I still can't slam the throttle to minimum, the motor dies at idle.

If the mark on the cam follower is idle, then it runs great at idle. It seems a little fast for idle, but what do I know? Also, if that mark is idle, why is the throttle allowed to go further down?
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I got the motor on the back of the boat, but it wouldn't start. Have I mentioned that it doesn't charge the battery? The elect. start was an upgrade and it never got the 12VDC output kit. I depleted the battery severely during the test and tune phase and I only have a little trickle charger (my good one is up at camp).

So, once it was on the boat, I got one crank from the battery and no more.

I had to be towed back to my mooring (in shame!).

I hooked up the solar charger and left it for 2 days.
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I went back out yesterday and it started right up, first crank. I ran it for 5 minutes and shut it down; it started right back up.

So except for the idle issue, I'm good to go. I might let the next owner worry about that. Looking at the water I dumped out of my test stand bucket convinced me that four stroke engines are the way to go. Yuck!


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## dabnis (Jul 29, 2007)

Somewhere in the linkage mechanism from the twist throttle handle to the carb butteryfly there must be an adjustment screw or stop. I can't remember what it was on our motor. Nor can I remember exactely what the cam and marker settings were. Unless somebody changed them and it runs all right that would be the last thing I would tinker with. Suggest you richen up the idle mixture until it roughens up then lean it back just enough to smooth it up, run the mixture as rich as you can. Sounds like a good motor if you can find the idle speed adjustment. A good detailed shop manual should show all the proper settings.

Paul T


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## CarbonSink62 (Sep 29, 2011)

I tried to richen up the mixture but I got 4-5 turns out and it still ran well. I put it back in all the way and then out 2 turns, that seems to work.

I'll re-read the shop manual (I have Clymer's, I think) and see what it says about the rich/lean setting and idle issues..

Thanks a lot for your help, Paul.

BTW - I worked on it in my back yard; as I pulled each tool out of my shop toolbox, I made sure that I had a tool to do that job onboard the boat.


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## dabnis (Jul 29, 2007)

4 or 5 turns out and still running smoothly may indicate an air leak somewhere? Maybe the reason it won't idle slowly? Suggest you check the manifold bolts torque. If snug maybe the gasket is leaking? Perhaps a very thin coat of silicone gasket sealer around the far outer edges. Be careful not to get any around the small passages.

Paul T


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