Evinrude smoking, losing power @ higher RPM's

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cvlngineer

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Jan 22, 2002
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I have a 1965 Evinrude Fisherman 6 hp outboard. It seems to run ok at idle, but when I give it a little throttle, it seems to lose power, miss and smoke. This happens both in gear and in neutral.<br />Could it be that the carb is out of adjustment, or does it sound more serious?<br /><br />Thanks<br />cvlngineer :confused:
 
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Riptide

Cadet
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Jan 2, 2002
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Re: Evinrude smoking, losing power @ higher RPM's

Just an idea only ok. I had the similar problem with my 1965 5hp Merc, my friend and I went in to see if we could find what was wrong. My problem was some how the gear oil/lube was gone and water was in there. Not sure if it was my water pump or what but anyway I had no gear oil/lube in the lower unit. I to lost power & had a lot of smoking in just the same way you have. This is only a suggestion but it wont hurt to check your gear box/lower unit to make sure it is full. <br /><br />Hope this helps. JG24AJ@cs.com :)
 
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DJ

Guest
Re: Evinrude smoking, losing power @ higher RPM's

CVL,<br /><br />I would be looking at the fuel pump diaphragm, if it has a seperate tank.
 
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johnkc

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Re: Evinrude smoking, losing power @ higher RPM's

cvl, your carb has a seperate adjustment for high speed , it may be open too much.
 
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cvlngineer

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Re: Evinrude smoking, losing power @ higher RPM's

Thanks, everyone. I will check each of these out tomorrow. I just bought the motor from an elderly friend of the family. It is my first outboard, so I know nothing about them. I know the man had just replaced the fuel pump, and I assume he replaced the filter, but I'm not sure. I think he also rebuilt the carb, maybe he forgot to adjust it. Do any of you know a baseline adjustment for them?<br /> I will also look at the lower unit, I was unaware that low gear oil could cause this problem. <br /><br />Thanks again,<br />cvlngineer
 
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cvlngineer

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Re: Evinrude smoking, losing power @ higher RPM's

This motor is a two cylinder, are there two separate high speed adjustments on the carb?<br /><br />Thanks,<br />cvlngineer
 
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alcan

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Re: Evinrude smoking, losing power @ higher RPM's

Hi cvlngineer<br /> If in fact you have a 1965 model (need model# to be sure)you have only one needle valve to adjust,the slow speed. It sounds like its rich on the high speed (getting too much gas).What do the spark plugs look like? Will motor loose power when you squeeze the primer ball hard? You might want to remove the carb and check for proper float hight,also float valve. There is also a little roller or rub block that rides a cam that opens the throtle. If this is missing or worn could be a problem.
 
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cvlngineer

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Re: Evinrude smoking, losing power @ higher RPM's

alcan,<br />Hello, I am sure it is a 1965. I haven't tried squeezing the primer bulb, what will this tell me? <br /><br />Could someone please post the Specs for the carb, float height, etc. I don't have the repair manual for it.<br /><br />Thanks,<br />cvlngineer
 
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wippb

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Dec 3, 2001
Messages
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Re: Evinrude smoking, losing power @ higher RPM's

Good advice from one of our seasoned members Harrison 20002<br /><br /><br />
First I'd to say that I'm not an expert like the one's here that answer all our questions. I've been boating over 30 years and I still need their help often.<br />This is ten reasons for all boaters to own a shop manual for their outboard engines.<br /><br />They have a section on your wiring diagrams.<br /><br />They give gas & oil mixtures.<br /><br />A section for tuneups, including Spark plug & ignition point gaps.<br /><br />Complete Tilt/Trim section.<br /><br />Lube, & Maintenance section.<br /><br />Complete servicing of water pumps.<br /><br />Lower end chapter.<br /><br />Very Important--- A torque setting for all bolts, including a tightening sequence for head bolts, etc.<br /><br />Section on automatic rewind starters.<br /><br />And a large troubleshooting chapter.<br /><br />The last one is worth the price of the manual[about$30 bucks]. Happy Boating. Hal.<br /><br />--------------------<br /><br />Hal H Virgo <br />
Click to expand...
 
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cvlngineer

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Jan 22, 2002
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Re: Evinrude smoking, losing power @ higher RPM's

This to answer some earlier questions.<br /><br />I checked the plugs, and they are oily. Are they supposed to have that black oily mess on them, is it from burning the oil in the fuel mixture?<br /><br />The fuel filter looks good, and the roller for the throttle looks alright.<br /><br />thanks,<br />cvlngineer
 
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sony2001

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Mar 17, 2001
Messages
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Re: Evinrude smoking, losing power @ higher RPM's

Because it faults in neutral as well I belive the carb has varnish deposits from old fuel. Especially the jet.
 
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alcan

Commander
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Re: Evinrude smoking, losing power @ higher RPM's

Hi cvlngineer<br /> Truely buying a manual is the way to go. If not you can check one out at the library. <br /> Float adjustment.<br /> Invert the carburetor body with its gasket surface horizontal, allowing the float weight to close the needle valve.<br /> If the float is not parallel with the casting face, bend the metal float arm carefully to make it even (parallel.<br /> Make sure your float floats.Clean everything,make sure little washer-like gasket on main nozzle is good. slow speed needle starts at 1 1/2 turns out from bottom.
 
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Fouled Plug

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Jun 29, 2001
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935
Re: Evinrude smoking, losing power @ higher RPM's

Just for laughs, cvlengineer, have you pulled the plug wires while running to verify it's hitting on both cylinders? My old 6 will run on 1, just not very well. Ignore me if I sound nuts! :D
 
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cvlngineer

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Re: Evinrude smoking, losing power @ higher RPM's

Bear,<br /><br />That is the very animal that I have! On the internet and everything, he he.<br /><br />I tested the compression in both cylinders. Pulling on the cord, I got 90 psi in both. I then cleaned the plugs and refilled the lower unit. I started it up and it did the same thing, however, I did discover something. When I disconnected the fuel hose to burn up the fuel before putting it away, I found that on the very last bit of fuel, right before it runs out, It runs like a striped ape. I repeated it a couple of times to make sure it wasn't just me, and it did it every time. I had it in gear with a good bit of throttle and right before it ran out, the rpm's came up and it sounded fine.<br /><br />This leads me to believe, through deductive reasoning, that it is a fuel problem, most likely in the carb. Does this sound right? Or am I way off base?<br /><br />Thanks alot folks for all of your help,<br /><br />cvlngineer
 
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DJ

Guest
Re: Evinrude smoking, losing power @ higher RPM's

When it takes it's last gasp-the fuel/air ratio is LEAN. You've got an over rich condition.<br /><br />It's time to do surgery on the carb. :)
 
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cvlngineer

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Jan 22, 2002
Messages
137
Re: Evinrude smoking, losing power @ higher RPM's

djohns19,<br /><br />Is there anything in the carb that you would suggest focusing on? What solvent would you suggest to get rid of the buildup?<br /><br />Thanks,<br />cvlngineer
 
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DJ

Guest
Re: Evinrude smoking, losing power @ higher RPM's

Needle and seat. Possibly float. These come in the carburetor rebuild kits. They're not very expensive.<br /><br />Just use the spray carb. cleaner you can get at the auto parts store. DON"T LET PARTS IN IT THOUGH.<br /><br />Remove every little plug and look for openings. Blow out with compressed air. Here's a hint, don't remove all of the plugs until you've identified a replacement in the kit.<br /><br />Same applies for jets, etc.<br /><br />You'll be surprised. You can do it in an hour.<br /><br />Last tip. Make sure you mark, make a drawing of, or take a picture of the carb. to spark advance linkage before you take it apart. You'll thank yourself later.
 
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cvlngineer

Petty Officer 2nd Class
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Jan 22, 2002
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Re: Evinrude smoking, losing power @ higher RPM's

thanks djohns...I'm off to tear something up.<br /><br />cvlngineer
 
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G DANE

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Nov 24, 2001
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2,476
Re: Evinrude smoking, losing power @ higher RPM's

cvlngineer<br /><br />Has anyone been monkying with the motor before you got it ? Has it ran ok with you at all? If is hasnt, i would check following:<br /><br />Is the main jet in the carbureator at all ? the main jet is lokated in the floater bowl, behind the drain plug. It is a brass jet whith threads.<br /><br />Is the center gasket in place ? the center gasket is circular and locaten between the floater bowl and carb body around the ventury tube from main jet - up to intake.<br /><br />Just two hints from DK, hope it is of any help.
 
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