197? 4 hp Evinrude won't run :o(

[steviecops]

Hi<br />It will start up on full choke, with the throttle advanced past the start mark, after a lot of pulling, but it only runs for about 10-20 seconds before it just loses power and dies. If I try to open the choke, or move the throttle back to idle, it'll die immediately. When it runs at high revs, it surges a bit.<br /><br />I've had the carb apart and thoroughly cleaned it several times now, although I haven't installed a new carb kit. I have installed a new inlet needle and seat though. I've had the flywheel off and changed a bad coil and cleaned and re-set the points. I've now got a really hot spark on both plug leads. I've had the reed plate assembly off and cleaned everything up. The reeds are sitting nice and flat and are not sticking. Compression is just over a hundred psi in both.<br /><br />The only thing I can think of doing now is fitting a new carb kit and changing the plugs. But somehow, I don't think that it'll make much difference. Could this be a faulty upper crankshaft seal? There wasn't any sign of oil on the magneto plate when I took the flywheel off, although there was some under the plate.<br /><br />Also, could anyone tell me what year this engine is? I've checked the old OMC site, but the numbers don't add up. The numbers on the plate say 44B37R B 4562.<br /><br />Thanks<br />Steve

 

[Paul Moir]

Re: 197? 4 hp Evinrude won't run (

She's a '74:<br /> 4hp models<br /><br />Has it got a built in fuel tank or is it separate? <br />I don't think it's the top seal - you were probably just seeing leftover oil from oiling the wick. In the outboards I've seen with blown top seals, everything gets covered in a mist of fuel/oil. The points get contaminated and you loose spark quickly.<br /><br />Have you tried priming the engine with a squirt bottle filled with premix? Does it help?<br /><br />EDIT: I see that this is a gravity fed model. Have you checked to see if you get good fuel flow from the tank? Does that carb have an adjustable high speed jet?

 

[steviecops]

Re: 197? 4 hp Evinrude won't run (

Hi Paul<br />No, there wasn't much oil under the plate at all, and on top there was nothing.<br /><br />I did try squirting some premix into the carb throat, and it fired up after a couple of pulls but died very quickly, like 2 or 3 seconds.<br /><br />I've taken the fuel line off the carb and opened up the fuel tap and there is a good flow. Each time I've taken the carb off, the bowl's been full of fuel.<br /><br />The high speed jet isn't adjustable, it's fixed.<br /><br />The only thing in the carb that I think could be a bit suspect is the main nozzle gasket. Could that give this type of problem if it was leaking?<br /><br />Thanks<br />Steve

 

[OBJ]

Re: 197? 4 hp Evinrude won't run (

Steve....get a carb kit and finish the job. It has probably got the original cork float???? As Paul suggested, make sure you have good feed from the tank. Make sure the choke is closing. Turn the high speed needle in till it GENTLY seats then back out 3/4 to 1 turn. Do the same for the low speed needle. If the carb is clean and your getting good gas flow, the engine should start, IF, the ignition system is up to par.

 

[Paul Moir]

Re: 197? 4 hp Evinrude won't run (

I'll tell you, if you suspect the main nozzel gasket is leaking you should replace it. A fresh one is very thick - much thicker than you would think.<br /><br />But that doesn't jive with it running only with choke and better with the spray. If that gasket leaks the engine runs rich not lean.<br /><br />Does the idle adjustment do anything at all? Is there any difference between fully closed and say 2 or three turns open? The idle circuit on the 4hp has a marked effect on medium speeds as well as idle - it delivers a significant amount of fuel.<br /><br />EDIT: Pardon the collision, OBJ! I'm inclined to agree. I always want to know what's under the soft plug on the top of the carb (just above the idle orifaces).

 

[steviecops]

Re: 197? 4 hp Evinrude won't run (

Hi OBJ<br />Yes, I'm going to get the carb kit tomorrow. It's the only thing I can think of that's causing the problem. <br /><br />Paul.<br />The thing with the idle adjustment is puzzling me. With the needle backed out 1 turn, the motor won't start at all. If I turn it out 1 1/2 turns it'll start at high revs and run for a while. If I turn it out another 1/2 turn, things improve slightly and it'll run at high revs with the choke open. But any more than that and it just dies. I've looked at the needle and it's in good condition. I've also taken the soft plug out and looked at the three holes in the carb throat and they are spotless.<br /><br />I know it's got to be fuel, but it's got me stumped. Maybe the carb kit will do it.<br /><br />Thanks<br />Steve

 

[Paul Moir]

Re: 197? 4 hp Evinrude won't run (

Well, you've got me stumped too.<br /><br />You say it has good hot spark right? Did you happen to test it over a wider gap or just the spark plug gap? If it'll jump 1/4" or more, I think we can rule out arc-over.<br />I can certainly see why you're thinking crankcase leak... No difference in the firing end of the spark plugs is there?

 

[Solittle]

Re: 197? 4 hp Evinrude won't run (

After you soak the carb but before you put it back together hit it with high pressure compressed air to get at all those places and passages that you can't see.

 

[alcan]

Re: 197? 4 hp Evinrude won't run (

Hi stevie <br />I agree with the others, that it sounds as your motor is starving for fuel (lean). The main nozzle gasket leaking will give you fits. When this happens it usually causes an over rich condition (flooding), as previously stated. Go ahead and install a new carb kit, including a new float and main nozzle gasket. Make sure that the low speed needle is in fact bottomed out. You may need to remove the knob and loosen the packing nut to be able to turn the needle by hand. So you can feel. Do not use tools to seat the needle. Back out the needle a turn or two before thightening the packing nut, so as not to jam the need into the seat. Adjust needle to 1 1/2 turns out from seated (for starters). Make sure you set the float level correctly. Now if the ignition is correct, as you say, and the carb is correct, and fuel is getting to the carb from the tank. This leaves compression. You say compression in both holes is over 100 psi, this is good. This leaves us with the crank case compression. You say you think the top seal is good. OK, how about the bottom seal? You will need to remove the power head to check this. You may also check the carb to manifold gasket and the manifold to crank case gasket. You may also test the seam at the crank case halves. Spray suspect areas with soapy water or oil for test. Obviously oil would be a better choice for testing intake. These small twins really don't use anything for a bottom crank case seal. You might try doubling the oil in the fuel to 24:1 or higher to 16:1 and see what happens.

 

[alcan]

Re: 197? 4 hp Evinrude won't run (

Hi Paul Moir<br /> Do you have Stevie's model# listed on a Europeon list? Was this model made in Belgium? I am just curious, I don't have anything for 1974 in 4hp with the fuel tank attached. I also do not have his model # listed.

 

[OBJ]

Re: 197? 4 hp Evinrude won't run (

Dang!...we are havin' fun with this 4 horse...

 

[Paul Moir]

Re: 197? 4 hp Evinrude won't run (

Aw, we'll get it runnin' right yet... <br /><br />Alcan - I don't have anything at all on that outboard, just the archive of the old model reference from the old Evinrude website:<br /> Model year reference, click here.<br /><br />There's some oddball model numbers there that are hard to find elsewhere. <br /><br />The '70s Evinrude brochures over on the Old OMC Site are Italian. The '72 - '75 brochures picture a 4hp with a built in tank and a 'funny' lower unit that looks like the F-N one used on later 4hp models. <br /> '72, has a good picture.

 

[steviecops]

Re: 197? 4 hp Evinrude won't run (

Hi Folks<br />It's difficult keeping up with the posts with the time difference! It's now 10.26 am here.<br /><br />I tested the spark on both with an adjustable gap spark tester and it jumped the 7/16 gap easily, with a nice blue spark and a snap with nice slow, easy pulls on the starter.<br /><br />I'm off to get the carb kit now. Fingers crossed.<br /><br />Thanks<br />Steve

 

[steviecops]

Re: 197? 4 hp Evinrude won't run (

Hi all.<br />Mystery solved!<br /><br />Whilst picking up the carb kit, I bought a new powerhead gasket, as I was almost certain that the carb kit wouldn't solve the problem and I was resigned to having to split and re-seal the crankcase.<br />Anyway, I fitted the carb kit, and new plugs, but it didn't make any difference, so off came the powerhead to start stripping it down. Here's what I found.<br /><br />It seems that the lower crankcase on these engines is sealed by the powerhead gasket, and a small rubber O ring that fits under it. When I looked at what I had, someone had taken the powerhead off at some point and never used a gasket when they put it back on!! They had tried to seal it with silicon, which obviously didn't work. The whole area down there was awash with oil.<br /><br />So with the new gasket fitted and some tweaking of the carb, the engine now starts and runs fine ;o)<br /><br />Thanks for all your help.<br />Steve

 

[OBJ]

Re: 197? 4 hp Evinrude won't run (

Outstanding Steve!!!!! Glad you finally solved the problem and a BIG thanks for posting the fix!!<br /><br />EDIT: OH YEAH.....It's Budweiser Time!!

 

[steviecops]

Re: 197? 4 hp Evinrude won't run (

Yeah OBJ, a few beers were in order! Very satisfying getting to the bottom of that one ;o)<br /><br />Thanks<br />Steve

 

[alcan]

Re: 197? 4 hp Evinrude won't run (

Sorry gang<br />my puter went south on me for the last few days. Good job Stevie. Glad to here of your sucess.<br /> Paul, thank you for the pictures and info. It is amazing how often models I have never seen turn up.