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Author Topic:   Motor conking out

prxmid posted 08-06-2003 07:39 AM ET (US)
Hello again, my, new to me 1989 Evenrude 70 isn't cooperating. Just had plugs, water pump, lower unit change etc. done. It runs great on plane. When starting or idle it constantly dies. may have to restart 10 times in a half hour, Then gets flooded and wont start at all. Had to row back (fortnately only 100 yds) A friend suggested that I just turn up the idle, but before I start messing with things wanted to know what else to look for
specktrout posted 08-06-2003 08:52 AM ET (US)
I had a similar problem on my '89 90 hp. It turns out I had two leaks in the fuel line. One was a small pinhole up where the gas line went from the tank to the tunnel under the deck. I figure a hook or a fish spine got it. The other was on the casing for the starter solenoid. On my '90hp there is a on/off switch to manually control the fuel flow right on top of the starter solenoid, it is the same one that has a little valve for running through engine tuner. Anyway, the casing had a small crack in it and fuel was leaking out. As fuel delivery is caused by negative pressure generated at the engine, any leak in the fuel lines is going to cause you to lose this pressure. After I fixed these two leaks, my engine quit stalling at idle. Hope this helps-
Hank posted 08-06-2003 10:46 AM ET (US)
Sounds like ignition. On my 90 Hp Evinrude, lost spark on two cylinders, ran at high speed, but died at idle. My problem turned out be bad ground connection at two ignition coils. However, could be many other reasons. If you have timing light, check for spark at each cylinder.
Could also be intermittent fault in key switch.
Hank
Bigshot posted 08-06-2003 11:19 AM ET (US)
Could be a million things but one thing is for sure.....don't listen to your idiot friend. There is NO idle adjustment on them. Either you have a fuel/air leak or your carbs are screwed. Either way get it fixed or blow a piston.
Bigshot posted 08-06-2003 11:19 AM ET (US)
Could be just bad gas or water in it, etc.
prxmid posted 08-06-2003 03:52 PM ET (US)
I'm telling my friend that you called him an idiot :)
Steve Leone posted 08-07-2003 03:07 AM ET (US)
Big "shot" across the bow. Your friend may not be an idiot, but turning the idle up is not the cure. If you are uncertain or unfamiliar with the functions of an outboard motor then do these simple tests in this order: Compression, first and foremost. Secondly, make sure you have proper spark. Thirdly,fuel. Make sure you are getting the right amount into the cylinders. One or more of the carbs may be at fault. Fourthly., exhaust. Restricted exhaust will cause problems, allthough uncommon, not unheard of. This is the "Zen" of outboard repair......May the "Force" not be with you.
Clark Roberts posted 08-07-2003 07:55 AM ET (US)
Suggest you have someone adjust the idle/air ratio needle valves (one on each of the three carbs)... very simple and may solve problem... happy Whalin'... Clark... Spruce Creek Navy
prxmid posted 08-07-2003 07:57 AM ET (US)
Thanks guys, I can't expect anyone to diagnose the problem across the internet but rather than narrowing it down the options get wider. As I just had the engine serviced they made note to tell me the compression was excellent for a 10+ yr old engine. New plugs and runs great on plane so I 'assume' spark is OK.
I have 2 six gallon tanks that I switch between so I don't believe it's water.
I going to find that idle screw if it kills me.
Steve
prxmid posted 08-07-2003 08:00 AM ET (US)
Clark, Is this a self repair (I have the shop manual) or does it need to be professionally done?
Bigshot posted 08-07-2003 09:47 AM ET (US)
Carbs rarely just go out of adjsutment that much. But.....a needle valve may have clogged or ,maybe the air/fuel screw fell out(seen it), etc. I doubt spark if she goes on plane, something screwy......hey did you maybe knock the little red arrow out of its spot and the enrichener is stuck on? I did that once and could not figure out for the life of me why it would not idle well,etc. Under the hood and somewhere near where the fuel line connects is a red arrow that swivels. It should lock into a little detent, try that.

You know I was just busting on your friend, but there still is no idle screw.
Clark Roberts posted 08-07-2003 12:42 PM ET (US)
Self repair!
DIVE 1 posted 08-07-2003 08:27 PM ET (US)
PRXMID,
When you switch fuel tanks, do you switch fuel hoses or use the same one? We had an internal collapse of a fuel line that resulted in the same symptoms you describe.
Jim
prxmid posted 08-07-2003 08:47 PM ET (US)
I use the same hose. What constitutes an internal collapse
of a fuel line?
waltuh posted 08-07-2003 10:51 PM ET (US)
Suggest you try using a different six gal OMC fuel tank as it could have an air leak at the four screw guage or on the pick-up tube inside. Could be time to upgrade to a used Tohatsu.... for real reliability.
Bigshot posted 08-08-2003 11:29 AM ET (US)
Been thinking about this and my guess on the enrichner valve is a good one. It can't be a carb or fuel line being all 3 plugs are geting wet. being that it runs good on plane suggests the enrichner valve again. What the enrichner does is squirts gas in the cyls, it is NOT a choke that starves air. So if she is getting an overdose of fuel.....viola. This would also explain why it runs good when it is cold....for a minute.
What else would cause all 3 cyls to get drenched in fuel?
prxmid posted 08-08-2003 12:20 PM ET (US)
Bigshot, I started to check enricher valve last night and a lightning storm scared me off. I'm going to start with the enricher valve and possible hose/tank air leaks and eliminate those two first. Then work up the food chain.
Will post results
DIVE 1 posted 08-08-2003 07:48 PM ET (US)
PRXMID,
When the fuel line gets old the inner skin may seperate and collapse from the suction of the fuel pump. At the same time, the outside skin of the fuel line may look fine and NOT collapsed.
Jim
prxmid posted 08-10-2003 12:32 AM ET (US)
Bigshot.. I found the enricher valve. There is no indent. It turns in about a 270 degree arc. It was all the way right, clockwise. That's where I left it,
Checked the fuel line, bulb is firm , no apparent air leaks.
Next I'll check the carburator needle valves

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Author	Topic: Motor conking out
prxmid	posted 08-06-2003 07:39 AM ET (US) Hello again, my, new to me 1989 Evenrude 70 isn't cooperating. Just had plugs, water pump, lower unit change etc. done. It runs great on plane. When starting or idle it constantly dies. may have to restart 10 times in a half hour, Then gets flooded and wont start at all. Had to row back (fortnately only 100 yds) A friend suggested that I just turn up the idle, but before I start messing with things wanted to know what else to look for
specktrout	posted 08-06-2003 08:52 AM ET (US) I had a similar problem on my '89 90 hp. It turns out I had two leaks in the fuel line. One was a small pinhole up where the gas line went from the tank to the tunnel under the deck. I figure a hook or a fish spine got it. The other was on the casing for the starter solenoid. On my '90hp there is a on/off switch to manually control the fuel flow right on top of the starter solenoid, it is the same one that has a little valve for running through engine tuner. Anyway, the casing had a small crack in it and fuel was leaking out. As fuel delivery is caused by negative pressure generated at the engine, any leak in the fuel lines is going to cause you to lose this pressure. After I fixed these two leaks, my engine quit stalling at idle. Hope this helps-
Hank	posted 08-06-2003 10:46 AM ET (US) Sounds like ignition. On my 90 Hp Evinrude, lost spark on two cylinders, ran at high speed, but died at idle. My problem turned out be bad ground connection at two ignition coils. However, could be many other reasons. If you have timing light, check for spark at each cylinder. Could also be intermittent fault in key switch. Hank
Bigshot	posted 08-06-2003 11:19 AM ET (US) Could be a million things but one thing is for sure.....don't listen to your idiot friend. There is NO idle adjustment on them. Either you have a fuel/air leak or your carbs are screwed. Either way get it fixed or blow a piston.
Bigshot	posted 08-06-2003 11:19 AM ET (US) Could be just bad gas or water in it, etc.
prxmid	posted 08-06-2003 03:52 PM ET (US) I'm telling my friend that you called him an idiot :)
Steve Leone	posted 08-07-2003 03:07 AM ET (US) Big "shot" across the bow. Your friend may not be an idiot, but turning the idle up is not the cure. If you are uncertain or unfamiliar with the functions of an outboard motor then do these simple tests in this order: Compression, first and foremost. Secondly, make sure you have proper spark. Thirdly,fuel. Make sure you are getting the right amount into the cylinders. One or more of the carbs may be at fault. Fourthly., exhaust. Restricted exhaust will cause problems, allthough uncommon, not unheard of. This is the "Zen" of outboard repair......May the "Force" not be with you.
Clark Roberts	posted 08-07-2003 07:55 AM ET (US) Suggest you have someone adjust the idle/air ratio needle valves (one on each of the three carbs)... very simple and may solve problem... happy Whalin'... Clark... Spruce Creek Navy
prxmid	posted 08-07-2003 07:57 AM ET (US) Thanks guys, I can't expect anyone to diagnose the problem across the internet but rather than narrowing it down the options get wider. As I just had the engine serviced they made note to tell me the compression was excellent for a 10+ yr old engine. New plugs and runs great on plane so I 'assume' spark is OK. I have 2 six gallon tanks that I switch between so I don't believe it's water. I going to find that idle screw if it kills me. Steve
prxmid	posted 08-07-2003 08:00 AM ET (US) Clark, Is this a self repair (I have the shop manual) or does it need to be professionally done?
Bigshot	posted 08-07-2003 09:47 AM ET (US) Carbs rarely just go out of adjsutment that much. But.....a needle valve may have clogged or ,maybe the air/fuel screw fell out(seen it), etc. I doubt spark if she goes on plane, something screwy......hey did you maybe knock the little red arrow out of its spot and the enrichener is stuck on? I did that once and could not figure out for the life of me why it would not idle well,etc. Under the hood and somewhere near where the fuel line connects is a red arrow that swivels. It should lock into a little detent, try that. You know I was just busting on your friend, but there still is no idle screw.
Clark Roberts	posted 08-07-2003 12:42 PM ET (US) Self repair!
DIVE 1	posted 08-07-2003 08:27 PM ET (US) PRXMID, When you switch fuel tanks, do you switch fuel hoses or use the same one? We had an internal collapse of a fuel line that resulted in the same symptoms you describe. Jim
prxmid	posted 08-07-2003 08:47 PM ET (US) I use the same hose. What constitutes an internal collapse of a fuel line?
waltuh	posted 08-07-2003 10:51 PM ET (US) Suggest you try using a different six gal OMC fuel tank as it could have an air leak at the four screw guage or on the pick-up tube inside. Could be time to upgrade to a used Tohatsu.... for real reliability.
Bigshot	posted 08-08-2003 11:29 AM ET (US) Been thinking about this and my guess on the enrichner valve is a good one. It can't be a carb or fuel line being all 3 plugs are geting wet. being that it runs good on plane suggests the enrichner valve again. What the enrichner does is squirts gas in the cyls, it is NOT a choke that starves air. So if she is getting an overdose of fuel.....viola. This would also explain why it runs good when it is cold....for a minute. What else would cause all 3 cyls to get drenched in fuel?
prxmid	posted 08-08-2003 12:20 PM ET (US) Bigshot, I started to check enricher valve last night and a lightning storm scared me off. I'm going to start with the enricher valve and possible hose/tank air leaks and eliminate those two first. Then work up the food chain. Will post results
DIVE 1	posted 08-08-2003 07:48 PM ET (US) PRXMID, When the fuel line gets old the inner skin may seperate and collapse from the suction of the fuel pump. At the same time, the outside skin of the fuel line may look fine and NOT collapsed. Jim
prxmid	posted 08-10-2003 12:32 AM ET (US) Bigshot.. I found the enricher valve. There is no indent. It turns in about a 270 degree arc. It was all the way right, clockwise. That's where I left it, Checked the fuel line, bulb is firm , no apparent air leaks. Next I'll check the carburator needle valves