1975 Evinrude 85 hp Need Professional Help!!!!

[jbwathen23]

Hoping someone could help me cause im about to loose my mind!! im pretty mechanically inclined and i thought i could fix anything until this problem... its a 1975 evinrude 85 hp.. it idles like complete crap.. sneezes idles up and down half the time cuts off after it sneezes... sounds like the bottom carb is where the sneeze is coming from.. ive replaced fuel pump new plugs rebuilt the carbs ( about ten times ) using carb cleaner and air.. i have my timer base air gapped at .005 ( i played around with that moving in .001 increments it runs better at .005) ive changed flywheels thinking i could of been a loose magnet.. replaced all the fuel lines and also by passed the tank and line going to the tank buy hooking it directly into the pump.. any ideas would be much appreciated.. i dont have a dva so i havent checks the power from the stator or coils.. boat ran fine last year sat maybe 3 months... starting to think it could be something with the reeds maybe???

 

[Bosunsmate]

check its sucking as much aas the other carbs, might be a worn lower seal

 

[racerone]

?????----------Why all this work without asking questions.------Report the results of a compression test today , not last year's values.-----Does spark jump a gap of 7/16" with a real snap ?-----Report those values and then we go from there.-----Testing and trouble shooting works.---Guessing does not work.

 

[jbwathen23]

forgot to add that i did a compression check too haha cant remember what they were but i know there were all in the 120s also forgot to mention that i had a buddy do a leak down test on it and he said it came out perfect... how would i check to see if the spark jumps a 7/16 gap? is there a tool for that?

 

[jbwathen23]

also the plugs are wet! almost like its flooding really bad.. the floats are level with the carbs turned upside down and the jets and floats valves are fixed to theres really no adjusting the carbs

 

[boobie]

You can buy an open air gap spark tester at most parts houses for around 8 $$$$.

 

[jbwathen23]

Ok I knew there had to be a tool for it.. I will pick it up tomorrow and take a video of it so you guys can hear what's going on.. I'm new to this forums thing so it might take a little bit to upload it

 

[Bosunsmate]

also the plugs are wet! almost like its flooding really bad.. the floats are level with the carbs turned upside down and the jets and floats valves are fixed to theres really no adjusting the carbs

Check that the primer bulb holds firm with the engine off, a badly set float or bad valve will cause wet plugs

 

[jbwathen23]

The ball stays hard... I've racked my brain trying to figure out what this thing can be.. I've spent a lot of money and alottttt of time on this ol gal these last couple months..

 

[Bosunsmate]

Need to check spark with sparkplug tester then timing

 

[emdsapmgr]

The only time the primer bulb should be hard is when you first pump it up when you try to cold start the engine. Once the engine starts and begins to draw fuel through the hose, the bulb will soften. But it should not collapse when running. That's normal. If it stays hard while running, you may have a fuel restriction which could include a bad ball valve in the primer bulb itself. Is the hose oriented in the right direction? You can also do another simple test for spark when cranking the engine. Put a timing light on one plugwire and crank the engine. The flashes from the gun will show the quality of spark: misfires, weak firing, no fires and intermittents. Check all 4 plugwires.

 

[F_R]

Sneezing at idle is a sure sign of running too lean. If it isn't caused by fouled carburetors, then it is something else causing it to be too lean. Let's assume (?) it is receiving enough fuel from the tank. Other things that can cause a lean condition at idle are an air leak into the crankcase, or throttle butterfly plates not closing completely, or not properly synchronized with the spark advance (opening too soon). I'm betting on one of the latter two.

BTW, wet plugs don't mean squat.

EDIT: Has somebody changed the idle jet orifice plugs? That certainly would make it idle too lean (or too rich). Should be part number 317474, stamped 27 (.027" orifice)

 

[jbwathen23]

how would you change the orfice plugs? If there the aluminum looking plugs just under where the high speed jet screws in or should I say behind the high speed jet then they haven't been changed.... I have the carb plates closed all the way at idle would like to know a little more about the sync with the spark advance

 

[jbwathen23]

Correction the carbs are not closed during idle I made sure they were synced with the cam roller diconnected.. then I set the cam roller to be set at start for the carbs

 

[jbwathen23]

Just did the spark air gap test it's Definatly firing at 7/16 gap with plenty of snap

 

[emdsapmgr]

The carbs need to be completely closed at idle. They breathe thu the holes in the main butterflys at idle. That's enough to keep them at even idle. So, if they are ajar (slightly open) that can cause uneven idling based on the timing advance. The cam roller needs to not quite touch the cam at idle. You should be able to slip a pc of paper between the two at dead idle. That way you know there is no pressure on the roller. You may need to pull the airbox cover off when setting this.

 

[Silvertip]

You said the plugs look wet. You have your answer -- it's getting too much fuel. Your carb work is either incorrect or there is ruptured fuel pump diaphragm allowing excess fuel to be drawn in through the pulse line. There is great value in having an engine specific "manufacturers" service manual for your engine if you intend to work on them yourself. It saves you time, money, frustration and can help prevent costly mistakes.

 

[jbwathen23]

Here's the video of it running Watch "1975 evinrude running like crap" on YouTube
1975 evinrude running like crap: http://youtu.be/lIScXrp7iVo

 

[F_R]

No Title

Idle orifice plugs circled. One on each side of both carburetors. ALSO, the two screws in front are not adjustments. They are to be screwed all the way in, with gaskets.

I don't think I have the manual for Link & Sync, will have to check. But those plates need to be closed at idle. If they open before the spark is advanced far enough it will sneeze and fart and probably stall.

 

[F_R]

Nope, closest manual I have is 1972, and I don't want to lead you astray with incorrect information on the Link & Sync. Suffice to stress the importance of a correct service manual when setting these things up. If it ain't right, it won't run right.