78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

[zigzag]

ok, here's the facts:

bought a 1978 evinrude 9.9 hp. wasn't run at all last year. took it home used fresh no ethanol 50:1 mix. fired up after three pulls. started on one pull afterwards. took it out on the lake and seemed to run great with no issues. forgot to run the fuel out of the motor when i was done. put the motor in the back of my car where it sat for about four days. it's been hot here. took the motor out today and it fired right up and idled ok. brought it up to wot and it started to surge then stall. tried this a few time with the same results. took it home, replaced a cracked fuel line from the filter to the carb. cleaned fouled plugs and restarted. ran ok, shifted to forward, ran ok for a few minutes. started to lose power, surged a little and stalled. plugs are probably fouled again, will start but runs erratically and wants to surge and stall. if i squeeze the primer bulb while stalling the motor picks back up.

still have to check to see that both cylinders are firing. i am really dreading the thought of pulling the carb. but i have a feeling!

any help??



here's an update, went out and started the motor up. pulled each plug individually and they're ok. it seems though that the primer bulb doesn't stay firm, like it is losing pressure. could it be a fuel pump problem? diaphragm maybe?



thanks guys

don't be too harsh as i am currently traveling on the learning curve!!

 

[Rick.]

Re: 78 evinrude 9.9hp / need some help!!

Re: 78 evinrude 9.9hp / need some help!!

First thing to check is the tank venting properly. Sounds like that could be your problem. The bulb is a fuel pump of sorts. It's purpose is to pressure up the fuel system and once the motor starts the motor takes over sucking fuel from your tank. With the motor running your bulb is no more than a fat piece of fuel hose so you can expect it to be soft at that point. You mentioned that pumping it brings your motor back to life. That would indicate your fuel pump isn't doing it's job getting fuel to the motor and when you pump the bulb your re pressurizing the carb. It could be a partially plugged high speed jet in the carb. but I doubt it by what your telling us. Here is a link that has very good information about your motor. A must read in my opinion. Don't worry, have not seen any examples of harshness on this site. Only when people ask questions and then don't listen to the replies. Best of luck. Rick.

http://www.sschapterpsa.com/ramblings/Ramblings.html

 

[jimdd810]

Re: 78 evinrude 9.9hp / need some help!!

Re: 78 evinrude 9.9hp / need some help!!

I would try pumping the bulb while it is running and see if it improves if it does then replace the fuel pump. If it dosnt it is time to rebuild the carb. Not had at all. I would rebuild the carb even if it is just the fuel pump.

 

[zigzag]

Re: 78 evinrude 9.9hp / need some help!!

Re: 78 evinrude 9.9hp / need some help!!

thanks for the help guys.

here's the latest, went back out and fired her up again. pulled the fuel line off the carb and cranked it over and had some fuel come through. then checked the fuel filter on the pump, that was clean as a whistle. AND THEN, i played with the primer bulb a little more. correct me if i'm wrong but there is a check valve in there right? well when the bulb is held with the arrow pointing down i can feel is pulse lose pressure and at the same time the engine starts to sputter and wants to stall out. however when i turn it over the motor recovers and runs like a top.

could my problems really be caused by a faulty check valve? that would really be a blessing if that's all it is! i sat there for 20 minutes testing this out. hold it up so the check valve is seated and it runs great, turn it over and i can feel the fuel draining back to the tank and the engine shuts down.

are these check valves a ball and spring or flaps? i assume it's ball and spring or something similar.

thanks again rick and jim, i do want to clean the carb but it ran great the other day (i guess the bulb was just sitting the right way) and was hoping to make that a over-winter project so i can take my time and not rush it. i'm pretty mechanically inclined but for some reason i fear having a box full of carb parts and a motor that doesn't run! just kidding, i'm gonna tackle it soon enough, just want to have some fun first.

 

[jimdd810]

Re: 78 evinrude 9.9hp / need some help!!

Re: 78 evinrude 9.9hp / need some help!!

well try a new primer bulb and new fuel line (ethynol resitant) I guess it could be the primer bulb it is not unheard of.
Goodluck

 

[zigzag]

Re: 78 evinrude 9.9hp / need some help!!

Re: 78 evinrude 9.9hp / need some help!!

yeah man. first thing tomorrow if i can find one. don't know if the shop down the road is open or not. gonna have to pick up a business card, every time i stop in is the days they're closed! oh well...

 

[dvincik]

Re: 78 evinrude 9.9hp / need some help!!

Re: 78 evinrude 9.9hp / need some help!!

Hello fellow watertime lovers-

I have a 1973 9.5 twin with the exact same problem you are working on. Just logged on and registered to see if I could get some hint of where to start with this #@%^& thing. I use mine sometimes as a downrig motor and simply transfer the fuel conncect from other motor. Fuel connect works fine on other motor. Something is not flowing somewhere. I am staying tuned and am anxious to hear the next update on this 9.9. Anybody else got any advice for my vintage motor I will gladly take it. Thank you gentlemen.

David V.

 

[zigzag]

Re: 78 evinrude 9.9hp / need some help!!

Re: 78 evinrude 9.9hp / need some help!!

well david here's an update for you. hope it helps. last night when i checked to see if the fuel pump was working i pulled the line off the carb (after the pump) and cranked her over. it seemed that it was pumping fuel however, i now think it was just pressurized fuel draining from the line after priming. it was dark out and i was tired.

today i took a plastic mayo jar, drilled a small hole in the lid and pushed the fuel line through and slid a hose clamp on the inside so it did not come out of the lid. i screwed the lid onto the jar. squeezed the primer bulb and fuel flows through fine. i then let all that fuel trickle out till it stopped. then i tried cranking the motor with the pull rope. did this about twenty times and no fuel was coming through.

i also noticed the water in my barrel is pretty oily and at higher speeds the engine kicks around a little. from all the reading i've been doing it seems as though the diaphragm is punctured letting fuel/oil mix flow into the crankcase. please guys correct me if i'm wrong but this would be the cause for the excessive oil through the exhaust (oil in the barrel) and the kicking around at higher RPMs would be the motor backfiring? i'm pretty sure that i have it narrowed down to the fuel pump and next in line would be the primer bulb.

on a side note, soon after i got the motor i fired it up in the barrel and played with it for a while. afterwards i put it back on it's stand in the basement. the next day there was a nice 6 inch round puddle of oil/unburnt fuel that leaked out of the prop onto the floor. at that time i read that a small amount was normal but now i think i know the culprit.


hope this helps.....still working at it!

 

[zigzag]

Re: 78 evinrude 9.9hp / need some help!!

Re: 78 evinrude 9.9hp / need some help!!

took the fuel pump off and took it apart. everything looked ok then i realized that i was missing a gasket. it's the valve housing gasket. i guess it was running without it. i'll have to wait until tomorrow to get a rebuild kit and see if that helps.

i don't know a lot about outboards but it all seems fairly straight forward so far. at very least once i get this thing purring again i'll know my way around under the hood. my buddy has a 2003 9.9 merc and i don't think he's even ever looked under the cowl. i always hear him saying 'that's why you have to buy new so you know you wont have problems' i think that's bull. one of these days i think he'll end up wishing he knew a little more about what's going on under the hood so to speak. at least he carries a collapsible paddle with him!

 

[zigzag]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

ok, ordered a replacement fuel pump and put it on today. fired right up and sounded like it was running much smoother. throttled up and sounded good, a few little kicks here and there. thought i was home free, then at about five minutes the motor started to slowly die down and eventually stalled. it didn't run rough then stall, it was just like i throttled it down slowly and then it quit.

it pumps water great, block doesn't get hot. starts right up afterwards with one or two pulls, with maybe a little choke action. pulled the tank apart and the pickup screen was clean as a whistle. gasket came off in pieces under the fuel line fitting on the tank. seems to idle fine like it would run all day. pulled the plugs out and they look ok, but a little fouled.

my original thought was the primer bulb check valves allowing fuel back into the tank breaking the vacuum, but like i said i'm new to outboards so i'm not really sure. still might try and replace the bulb. been scouring the hoses looking for cracks and possible air leaks.

here's a question for you guys, at full throttle and assuming there is an air leak somewhere, would it be sucking air into the lines slowly until there is enough air to break vacuum or stall out the motor?

i'm confident i can fix this thing without taking her down to the shop.

coils maybe? gives a good spark off the block when i pulled the wires. still diligently trying to avoid a carb cleaning!:redface:



any more suggestions from you guys would be great, thanks in advance!

 

[bktheking]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

I had a motor that would do this, ended up being a wire going into the powerpack was shorting, would work one second then die and then start right up again.

 

[zigzag]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

do you think i should start looking at the coils, compression, carb? in what order is suggested?

i just dumped all my fuel into another container and went and got 1 gallon of gas and made up a new mix. something i don't think i've really mentioned yet but it seems like it's really running rich. the exhaust really smells like gas and there seems to be a pretty good build up of milky oil in the barrel of water. not a lot but enough that it's noticeable. i don't really know if this is normal or not. almost like the fuel isn't getting completely burnt. top cylinder seems to have the weaker spark when i pull the plug wires. each has a spark but when i pull the bottom wire it really wants to stall, however the bottom plug seems like it always has more 'fouling' to it. seems to be running a little warmer but the water in the barrel is also pretty warm from sitting in the garage for a few days, prob around 80-85 degrees.

 

[bktheking]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

You could have a coil going out, any noticeable cracks?

 

[zigzag]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

nope, nothing noticeable. the motor is in very good overall condition. nice and clean and i don't believe it has been used all that much. i did notice some fuel mix that looks like it has been leaking out of the lower spark plug hole. not much at all but enough to notice. i read that it could be a cause of low vacuum pressures. have to try and look at the carb gasket also. gonna go get some new plugs and try and borrow a compression tester just so i know.

 

[Tim Frank]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

Make sure that your gas cap is NOT tightened fully....that will cause a vacuum in the tank.
Those caps are "three position"... off/run/lock down for transport.

It could cause your fuel problem.

http://forums.iboats.com/showthread.php?t=402503

 

[zigzag]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

yep, i've tried venting the tank all sorts of ways including with the cap off.

i went to the auto parts store and picked up two new plugs. was going to try and borrow a compression tester but they don't loan them out, only sell them for 30 bucks. going to have to see if my mechanic has one i can borrow for a few minutes.

went ahead and put a piece of clear vinyl tubing from the pump to the carb to see if the motor was starving for fuel or not. it isn't. the only thing i have noticed is that after i shut it down or it stalls is that about a minute later air bubbles start working back from the carb into the fuel line, creating an air lock at the fuel pump. not sure if this is something wrong or not, just an observation. it seemed like it was pulling air from around the carb somewhere.

SO, i decided to jump in and pull the carb. i have a clymers service manual and some good online resources to help me along. i've been taking pics at every step and every angle! so far it hasn't been too difficult (fingers crossed!)

hoping to get her all cleaned up and put back together here in the next few days. we'll see what happens. any problems after this and i'll start looking at the electrical side of things.



you know, after tearing this old girl apart and fixing her up, she better give me the lovin' i deserve!

at least i'll know all her secrets so the next time she needs an attitude adjustment i'll know just what to do!

 

[zigzag]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

carb came off. was very very clean. soaked it for about four hours anyway and put her back together. with a clean carb, new fule pump and fresh plugs she's definitely running stronger. the clear vinyl tube proved to be a great diagnostics tool!

fired the motor back up and she was running strong, meanwhile air bubbles started popping out of the fuel pump. i watched them collect in the tube and bog the motor down when they hit the carb. this time however the motor did not stall so i don't think everything i've done so far has been a waste.

now i'm down to fuel lines from the pump back to the tank. should be a breeze from here on out.


i know this kinda seems like i'm posting this for myself. after all i don't have too many replies but being able to go back and read through this like a log book has been quite helpful to me and hopefully this will prove to be a help to someone else sometime. considering i've never worked on an outboard before maybe another noob can get a sense of where to start and what to look at or eliminate.

 

[dvincik]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

This is great stuff. Your helping me more than you know. When I get ready to tackle this same issue I can draw on your experierences. Thank you so much for your post.

David V.

 

[zigzag]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

glad to hear it! just a little update for you then... after basically tearing everything down and putting it back together i realized the i didn't check the fuel line that is connected to the clip where you plug the tanks fuel line to the motor. i'm almost embarrassed to admit it but i think what the problem ended up being was that the rubber fuel line at that connection was loose. i could have pulled it off with little effort. i took it apart and cut off the zip tie that was on it and put another on. NOTE: at the time i didn't have another suitable fuel line clamp so i used another zip tie, the way it goes back into the motor casing is tight and that's just what i had on hand.

since, i've had the motor out three times and seems to be working just fine. i think it might still be sucking a little air but when i swap out the zip tie my hope is that it will stop. the only thing i've noticed is that sometimes it takes an extra pull or two to get her going. all in all, i'm happy and now if something goes awry i'll know where to start looking. i look at it as a process i needed to go through so i would 'learn' the motor so all that tinkering will serve me better the next time!

 

[CarlitoIsMe]

Re: 78 evinrude 9.9hp / fuel delivery issue?, slowly dies out after 5 minutes

know this kinda seems like i'm posting this for myself. after all i don't have too many replies but being able to go back and read through this like a log book has been quite helpful to me and hopefully this will prove to be a help to someone else sometime. considering i've never worked on an outboard before maybe another noob can get a sense of where to start and what to look at or eliminate.

Nope, I?m thinking ?Thank God I Found This Thread.? Hello Zigzag. This thread has confirmed all I've read so far about, heard from others.

Same problems with my 1977 9.9. Newbie here. First boat with motor. 23-foot Sailboat. Evinrude will run just sweet for an hour or so, then dies down. Squeezing the bulb works every time to get her back up and running, then 5-10 minutes later, ?plehhhhh?, pump pump pump and she?ll run just fine. I?m running an internal tank and I also use a 3 gallon portable (only one or other hooked up at a time). I?ve been out 5-6 times since I bought the boat. Haven?t had the motor die on me with the portable. The bulb on the inboard just doesn?t feel the same as the portable.

So, with advice, and thankfully with a very thorough confirmation here, I did buy a new bulb and fuel line for the internal tank. I?ll clean the vent tube and screens when I install the line tomorrow.

Just to be safe, I bought a brand new fuel pump, and a kit. I?ll install the new pump, (looks easy enough) tomorrow. My newbie question is: what do I use to lube the gasket? Or do I at all? (ahhh, I?m ducking from the anticipated beating I?ll take for that question).

With the kit, I?ll rebuild my old pump at home, where I can take it slow and easy. I do want to learn and do as much work as I can on my ?what seems to be? a great little motor.
I need a real manual for this thing. The CDROM information I?ve purchased over the internet just doesn?t cut it. Too generalized, not a lot of specific information for the 9.9.

/semi-hijack off.

Thanks. I do believe this will solve the problem. I need the little engine to motor me at least an hour until I get to the first spot where I can actually pull up sails. Channel?s just too narrow to tack and jibe.

I?ll be reading this thread with interest. I want to see you, and I, out on the water having fun for a change.

So far, this boat has been a large pain in ?