Help me diagnose

1984 Evinrude 25hp manual start
Rebuilt carb compression good at 90psi both cylinders
New plugs

Very hard to start takes many pulls and backfires when trying to start goes from extremely hard to pull to alittle easier. Once it starts it runs fine but has some issue idling. Once it starts it smokes a good bit like it's flooded. I am thinking it might be a bad power pack and it's not getting good fire which is making it harder to start but once started will continue. Any thoughts?

Test the coil and points. sounds like a electrical issue to me

if it runs then the coils are just fine. check to make sure the choke plates close 100 completely againt the carburator walls, thencheck that the timing advance moves very freely under the flywheel and will move all the way to the advance stop screw, these often get gummed up and wont advance when cold and thuss hard to start. as far as the smoke gos once its started aint anything to worry about at all. every @ stroke out there does that, It is the fuel-oil mixture that is in the crankcase and cylinder that the gas has evaporated and leaves behind the oil.. nothing to worry about at all. another thing to check is the flywheel key, but you must remove the flywheel to check it, if it hasthe slighest groove in it where the flywheel meets the crank it is junk and will throw the timming off.

Here's some more info it gets harder to start after running it awhile. Yesterday at the ramp it started second or third pull and the more I ran the harder it got to start each time. Now this morning I went out and it fired up second pull...

make sure your gas tank is vented, if the vent aint open it will cause a vacume in the tank and actually try to suck fuel back from the enging after you shut it off, could be that the coils are breaking down when getting hot but I seriously doubt it. the spark MUST be able to jump a 1/2" gap when pulling the rope, dont just go by looking at the spark at the plug gap. get a real spark tester or borrow one,

I'm positive the tanks is vented well, if it wont jump a 1/2 inch gap then what?

It sounds like you cleaned your carburetor, but maybe did not put back in the proper settings..maybe. When you stated that you fired it up and it ran some it back fires. Possible fuel delivery issue, but we need to also look at your ignition as well.

***Please when your engine is running please note if water is being discharged out of the tale tail and your engine is cooling, if not shut down or you could be overheating your motor and causing it to seize up and have difficultly starting. Poor or low compression can also be the cause of difficult starting and poor running and idling.


But 1st thing's first, lets do some simple diagnostics.



I'm going to make a few comments or suggestions that make it easier for you to give important information and in turn make it easier to help you.

There are 3 basic things that a motor needs to run (these are general statements):

1.) Compression
2.) Spark
3.) Fuel

Compression: You have supplied the first bit of information. You stated that the compression on both cylinders was 90psi. At lower end of decent compression for that motor, but we can get to that later.

Spark:

The second piece bit of information is spark. Basically you need to assess the health/condition of your ignition system.

You need to check your spark and its quality. It needs to jump a gap of no less than 1/4 inch and have a good blue snap and color.

You will need a spark checker. Here is an example of a spark checker. About $6 at auto parts store.(great to have). I borrowed the picture from JbJennings



Process to check spark.

- Remove both spark plugs from motor, it makes it easier to pull the starter rope and prevent accidental starting (I know this would be great to you right now...ha ha)

- Connect the spark checker to the ignition wire boot and then ground the checker to motor with end clip. Put the spark checker where you can see it and gap the checker for a minimum of 1/4 inch.

- Pull the starter rope or turn over the engine with an electric starter and see if you get a spark and look at its quality. Repeat the process for bottom cylinder wire.

If you get no spark or a weak inconsistent spark then you will have to investigate your ignition system and pull off the flywheel.

- make sure the ignition wires are secure and have good contact with the coils. Inspect for any wire frays or potential unintended grounding.

You have power pack for your motor and it contains the equivalent components of the points and condenser. You also have two external coils.

Fuel:

- You stated that you have cleaned the carburetor, great. But it would be better to have been cleaned and have carburetor kit to complete the job....but we can get back to that.

- These are going to be the initial settings for the carburetor for starting purposes. Your will later fine tune the settings.

Facing the carburetor you will notice an adjustment needle on the top of the carburetor.

Here is a link to a diagram of your carburetor. I don't have your exact model number....so will do the best I can.


https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1984&hp=25&model=E25ECRS&manufacturer=Evinrude&section=Carburetor




- (part number 25 in the diagram) is your slow idle needle. You will gently turn in (clockwise) until the needle is gently seated..please don't force. Once seated, you will turn out (counter clockwise) the slow idle needle 1 1/2 turns. Leave it there for the time being.

- Your (part 19 in the diagram) high speed jet or orifice is fix and only needs to be cleaned and blow out with compressed air.

Once you get your motor started then you can get guidance on fine tuning the carburetor. Again make sure the motor is pumping water and cooling.


Please keep us posted!!

Checked spark and it checks good no problems jumping a 1/2 inch gap, when I cleaned the carb I had all intentions of putting a kit in it but everything looked brand new like someone had just rebuilt it. This ain't my first carb rebuild and I can pretty much tell when things need replacing. I did set the idle speed screw just as you say 1.5 turns out.

Today it is starting on the first or second pull almost religiously. Let me run this one by you and see what you think, yesterday afternoon I noticed that the fitting where the pee hole exists the power head was leaking. As it leaked it ran down the power pack and down into the lower cowl. Could this water possibly be shorting out the power pack after it runs for a while and be causing my starting issues? And now that it has dried out again it's starting like it should? Today I found a new fitting a 1/8 npt tap and fixed the leak but its rained all day and I won't get to test this out till tomorrow.

Still having issues, I am starting to think it is some sort of timing issues but ill let yall decide. I took a video of what it's doing im not sure how to explain it.




What is this adjustment for and what is the proper procedure for setting it, there are about a half dozen marks where someone has been moving it around some of them 2'' from where it is set now. I feel like this may have something to do with my issues.

Sounds like a timing issue to me. Almost like the timing is advancing too far. One thing I was noticing in the vid, I don't see any of the linkage on your carb moving. Is your carb opening up as the throttle is increased?

JMichael said:

Sounds like a timing issue to me. Almost like the timing is advancing too far. One thing I was noticing in the vid, I don't see any of the linkage on your carb moving. Is your carb opening up as the throttle is increased?

Click to expand...

I never advanced the throttle I was trying to idle it down if anything. To make it even more confusing I went out after supper and it fired up and idled fine shut it down and cranked it up multiple times revved it up idled it down no issues. :x. I am truly lost...

From your video, it sounds to me like you have a lean sneeze, slowly open up the L/S needle from the 1.5 turns out toward 2 see if the sneeze gets better (less often or goes away), 1.5 out is a general starting point where you end up doesn't matter. I have found on most of my engines if the L/S is set too lean they are hard to start especially cold. Does that engine, have a primer/enricher versus a choke? If it does and it is still hard to start, especially when cold, that may be causing some of your problems. Good luck

bbstacker1 said:

From your video, it sounds to me like you have a lean sneeze, slowly open up the L/S needle from the 1.5 turns out toward 2 see if the sneeze gets better (less often or goes away), 1.5 out is a general starting point where you end up doesn't matter. I have found on most of my engines if the L/S is set too lean they are hard to start especially cold. Does that engine, have a primer/enricher versus a choke? If it does and it is still hard to start, especially when cold, that may be causing some of your problems. Good luck

Click to expand...

Not sure what a primer enricher is so im going to say no. As far as the lean sneeze that may be the answer I did play with the low speed adjustment.

Aaron, the primer/enricher is used on some models versus a choke. A choke basically restricts how much air can enter the engine versus how much fuel is available, an enricher doesn't restrict the air it adds extra fuel instead. I have an 87 6hp Johnson it has an enricher instead of a choke. To operate the enricher on my engine, when cold starting, you pull out the enricher twice (this is giving a shot of fuel into the system) leaving it out on the second pull and then crank the engine, once it starts wait a few seconds and push it back in such as pushing in the choke. I may not be exactly right as to what is taking place inside the enricher but it is basically giving the engine extra fuel versus limiting air.

Aaron, I looked at your video again, I am about positive you have an enricher, should be the left button/knob as you are looking at the engine. Next time you go to start the engine when it is cold try what I suggested on my 6hp, when your engine is warm or has been running for a while make sure it is pushed in all the way. If you listen real close with the hood off and the engine not running you should be able to hear the enricher shooting fuel into the intake when you pull it out. Once your engine is warmed up you should not have to use it again for the day. Let us know how you make out.

No sir the left it a choke the right is a killswitch.

Aaron, you got my curiosity up so I had to look at a parts breakdown for an 84 Evinrude/Johnson. First off let me say it is your engine, you have it in front of you I don't and I am certainly not going to argue with you about it, but from what the parts breakdown shows for an 84 it doesn't have a choke it has a primer. Look at the left knob, under the cowl, does it have a cylinder with two small fuel lines on it, if it does it is a primer, if it has linkage that operates a butterfly it is a choke.

this motor plane and VERY clearly has a choke not an enricher. the choke plate is seen very clearly in the video even if you dont press play.

Aaron, out of curiosity could you tell us the exact model code from the ID plate. I went back and read everything posted so far, am I correct from what I read that you are not the original owner of the motor (you mentioned you could see where someone had tinkered with some of the linkage)? Assuming you are not the original owner, is this the first time you tried running it? If not did it run OK before and just started doing this? If it was running OK before what has been done/changed just before it started acting up? You mentioned about cleaning or going to clean the carb, my guess is that in the end this will be a fuel related issue. Also wondering if a PO may have changed some parts around (such as the carb)??

could be that it's sucking air from somewhere that it shouldn't. that screw that your pointing to with the screwdriver is most likly the timming advance stop. for setting the timming to its maxamum advance when the throtol is fully opened up