15 Evinrude fuel issue

[goblerblaster]

​I got a 9.9 Evinrude model E10rcid 1981 model that had a 15 hp evinrude carb on it. This carb was gunked up so I took it apart, soaked it in Berrymans carb cleaner bucket, put on a carb kit , and re-installed. The motor would start but only run with the choke pulled out. I repeated the cleaning process and had the same result. I got a 9.9 carb from a guy that posts on here , cleaned it and put a new carb kit in it- I did pull the two knock in plugs in the carb to make sure no gunk was hiding behind them- and put it on.... same result. Really Hard to start and then only run with the choke out.

I went back to the 15 hp carb, cleaned it again, re-installed...same result. Then I figured it must be fuel pump or fuel line, so I took the fuel pump off a good running 15 hp Evinrude, replaced the fuel connector that the gas line from the tank connects to, replaced the 5/16 fuel line from the connector to the fuel pump, and replaced the fuel line from the fuel pump to the carb with the new yellow line that allows you to see gas is actually in the line. When I hooked everything up and pumped the fuel line primer bulb I could not see gas in the line that goes to the carb. I took off the line at the carb and pumped the bulb and gas squirted out. I reconnected the fuel line to the carb and after about 15 pulls finally got the motor to start. It would still only run with the choke about 1/3rd of the way out. I dosed the gas can with a heavy round of SeaFoam and kept it running for about 15 minutes by feathering the throttle and pushing the choke in and out. When it died, I had a lot of pulling to no avail so I took the fuel line off the carb, pumped the bulb and gas squirted out of the fuel line. I reconnected the line and the motor started on the second pull. I kept it running at fairly high rpm and started backing out the lean/rich mixture knob.

Once I got it backed off to about 2 3/4 turns from lighltey seated, it finally would run without the choke being out any at all. I let it run for 45 minutes at varying rpm and it finally seemed to be idling pretty good and reving up with minimal hesitation. I killed the motor with the kill button and immediatly tried to restart. NOTHING again.

I am getting good spark, new plugs and gap set correctly. When it is running it does not miss or sputter.

Could this be some type of vapor lock? It seems that disconnecting the fuel line at the carb has an impact on it starting. Also, It seemed weird to me that when I put the fuel pump on and pumped the fuel line bulb- no gas came through the line going to the carb until I disconnected the line at the carb and then re-installed it. I know this carb is not supposed to be vented, but could it be that the packing washer around the rich/lean needle is too tight and not allowing any air in since I had to back it off 2 3/4 turns to get it to run without the choke being out? How come it will run for 45 minutes and not restart within 20 seconds of me killing it ???

Any suggestions or ideas would be appreciated. This is not the first one of these I have worked on and I have rebuilt a bunch of carbs...this one has got my goat !!!

 

[flyingscott]

What is the compression and have you done the link and sync did you use a factory or aftermarket kit. That carb does NOT vent around the low speed idle jet, is the roller on the carb linkage. Somebody is going to say you need reed spacers and the exhaust tuner to make it a 15 hp that is wrong your motor only needs the carb.

 

[oldboat1]

Did you remove the domed plug at the top of the carb and clean the passages underneath (idle passages)?

 

[goblerblaster]

THE compression is 115 per cylinder. I don't know what "link and sync" means. I did remove the domed plugs and cleaned under them. I really do not think the carb is stopped up coz I have soaked it, cleaned it with small wires, used compressed air, etc. The reed valve question was one that I had, but why would it run good for so long if it was a reed valve issue? Doesn't look like that would be a start and stop issue............

I just can't figure out why it will run for so long and then I kill it- in other words it doesn't die from running out of gas- and it will not re=start.

 

[flyingscott]

The link and sync is when you set the carb to open at a specific point on the magneto cam. The roller on the carb linkage hits the mark on the magneto cam and that is where the carb starts to open take a look at that. I did not say anything about your reeds.

 

[w2much]

I have gone nutty on a few of these also. For me usually it is because I look at the needle valve with my "expert eye" and set the float to where it should be. I try not to replace parts and therein lies the problem. Needle valve sticks, float not quite set right, tried to get away with carb cleaner instead of a good soaking then blowing out with compressesed air..
Often you will see air in the fuel line at slow speed , it moves through as the bowl empties the fills again with fuel. At low speed this should not be an issue as you are not using more fuel than the bowl can hold.
Did you change out the fuel lines? All of them ? they may not be ethanol resistant.
You may also remove the fuel pump, plug the vacuum hole and gravity feed the carb, Bad fuel pump will eventually drown your crankcase in raw fuel.

 

[racerone]

A carburetor has to be vented !--Without a vent it simply will not work !

 

[goblerblaster]

I have replaced all the fuel lines. The fuel pump I have on now came off a 15 Evinrude that was running perfectly, so I am sure it is good.

Racerone...how is this model carb supposed to be vented??? There is no veny hole or vent line on it. Does it vent from leaking air at the needle packing?

 

[racerone]

There must be atmosheric pressure on the fuel in the bowl !----Air rushing through the venturi creates a low pressure in that area.--The atmospheric pressure then pushes fuel into the airstream from the bowl.---Carburetors 101 it is.----The vent hole should be fairly obvious on that carburetor.

 

[scout-j-m]

I think the vent hole is the hole to the left of the low speed needle in the picture below. The carb on the right is a 15hp.

 

[OptsyEagle]

Yes. That is the vent hole. If you can blow into it easily then it should be clear. If you can't get your lips on it, perhaps a small nipple on a compressor might work to confirm if it is clear. Could probably do that without even taking it off the motor.

 

[oldboat1]

I clean the air vents with the jets and all other openings during soaking and blowing with carb spray. Like OptsyEagle says, you can try cleaning the vents in place with compressed air (I would use carb spray).

If you mixed seafoam or any other decarboning solvent in the gas tank after you cleaned the carb, there is a chance that whatever stuff you loosened up in the tank and lines has settled in the carb. The only way to be sure is to pull off the carbs again, disassemble and clean them -- all passages again, including the idle passages (maybe the idle passages in particular). Also need to replace any filters you may have in place.

 

[goblerblaster]

I took the carb apart again and soaked it in Berrymans cleaner bucket for 30 minutes. This was with the welch dome plugs removed. I cleaned out all passages with a needle and small wire. I then blew compressed air through every hole I could find. I put a new float , float needle, and seat. New gasket to where the carb bolts onto the engine block.

Primed it up and after about to pulls it started/ BUT it is still not wanting to run good without the choke being 1/3 out. After I keep it running for about 5 minutes, I can then oush the choke in and it will keep running- as long as I don't give it gas. If I twist the throttle to rev it up, it will cut out unless I pull the choke.

Is there any other issue that would be causing this besides a clogged carb? I am confident that this carb is clean, and so was the other one I had on the engine- but the problem was the same no matter which carb is on it. Carb is getting gas as I can see the gas in the clear yellow gas line connecting to the carb.

 

[racerone]

What other trouble shooting steps have been done on this motor?----It is not always a carburetor problem.

 

[jakedaawg]

Did I read that you replaced the fuel lines with the yellow line?

If that is the case, you can use the yellow line on the pressure side. You can run into issues on the suction side though as it has a tendency to collapse in some cases. Just a thought.

 

[goblerblaster]

The yellow fuel line is running from the fuel pump about 10 inches to the carb and is not collapsed.

Other items have been compression check- 115 psi per cylinder-, and new spark plugs, good fuel pump, and new fuel lines and gas connector for the part that hooks to the tank, carb kit.

I just feel certain that the current carb is clean and unclogged-as I was with the other carb...but the motor runs the same with either carb installed.

 

[oldboat1]

Check the spark with an adjustable spark tester. New plugs doesn't mean good spark -- need to insure that the ignition is sending a strong jolt to the plugs. You should see about a half inch spark using a tester.

If you can only run with the mixture needle 2 3/4 turns out, something is wrong somewhere.

 

[racerone]

Somehow most folks jump all over the carburetor / s when there are motor issues.----Other trouble shooting needs to be done.----Look into reed valve issues.-----Look into crankcase compression issues.

 

[oldboat1]

Reed issues (still fuel delivery) don't show up in cylinder compression tests, but can give you a number of other issues -- maybe subtle, maybe not so subtle. Inability to tune it in is a potential symptom.

you might be using an unusually rich adjustment (choking or air/fuel mix) because of an air leak -- crankcase compression issue. Might be a crankcase seal or reeds, maybe a lower shaft seal (would look for fuel leaking out up around the driveshaft splines) -- can also spray some WD-40 around the intake manifold when running for a down and dirty test (shield the carb intake), including down around the base of the powerhead. If rpms increase, can indicate a leak.

 

[goblerblaster]

OK, i pulled the 15 hp carb and tightened the bolts that hold the manifold onto the block. I got 1/4 to 1/2 turn on each of the bolts. I put the 9.9 carb back on and cranked it up. SURPRISE !! it runs without the choke being pulled out !! I can run it for 10 minutes, kill it, and it will start back up. After several start/stop cycles in the barrel, I put the motor on the boat and make my 10 minute trip to the lake.

Launched the boat and pulled the rope about 20 times and finally get the motor to running. Motor ran out good- no missing or hesitation- for 10 minutes. Then , I killed the motor with the kill button. Upon trying to restart, it took about 10 pulls, but once started it ran fine for another 20 minutes at all rpm levels. I pulled up to the ramp and killed the motor, backed the trailer down, tried to start the motor to no avail for about 15 pulls, and loaded the boat with a paddle.

Got home, had a beer, hooked the garden hose and muffs to the motor, and it cranked on about the 10th pull and ran fine. I can kill it and sometimes it will start right back up on 1 or 2 pulls. Sometimes it takes 10 pulls. I can still see gas in the fuel line attached to the carb. It runs without the choke being pulled out at all.

Now, I don't know if swapping carbs was the better result or if it was tightening the bolts on the manifold. I think I will put the 15 hp carb back on it just to see if there is any difference. Thanks to all for suggestions. I may have this thing running good enough to sell it before too much longer !!