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1969 Evinrude 9.5hp

B

BRUPP79

Regular Contributor
Well took out the auction 9.5 Evinrude tonight. Runs great at above idle. It has a sneeze or cough if you turn it down low to troll slow. Low speed idle is super touchy. It will adjust, but when you turn idle down low (guessing below 1000 rpm) it will sneeze or cough kinda hard, sometimes die. Pump looks to have been rebuilt/changed as there is a rubber not cork fuel filter gasket. But I ordered a pump kit anyways. Carb kit is on it's way as well. Had, I am guessing by the lack of blue over spray paint, the second set of old Champ J4J plugs in it. Ran a hair better with Champ J4C's in it. Might try J6C's tomarrow to see if that helps more. Any you guys experience these symptoms? My guess is 1969 parts are time for a change.
 
A sneeze usually indicates that it is running too lean

Hopefully a through clean and new parts from the kit will sort it.

The currently recommended plugs are J4C gapped at 0.030"

J6C are hotter and might help if there is any tendency for the plugs to foul during prolonged low speed operation
 
My 68 sneezes / coughs whenever in a barrel.

Warmed up, after WOT on the water, it happens much less, if at all.

The low idle adjustment : 1.5 turns from seated is too rich for mine. I set it below 1 turn,... it's enough.

The assumption is that the low idle needle and seat is worn, allowing more fuel through, creating a richer mix.

If the cowl is off , and the symptoms disappear , with better performance, the exhaust seals are possibly bad and she's inhaling her own exhaust.

Good luck man.
 
Brian, this is often a crankshaft seal....hopefully the upper cylinder, as it's much easier to change. They take the same seal top and bottom and are often destroyed by ethanol because they are mostly pure latex rubber. I have changed dozens of them. It seems that usually it's the upper crank seal, however, so it's not too bad of a job to remove the seal with a small self-tapping screw. I have an extra long bit with a heavier shank which I drill a small hole in the seal after providing a protective wrap on the crankshaft with a piece of aluminum or thin tin. There are tools available to remove the seal but I have gotten by without one all these years.
 
timguy said:
Brian, this is often a crankshaft seal....hopefully the upper cylinder, as it's much easier to change. They take the same seal top and bottom and are often destroyed by ethanol because they are mostly pure latex rubber. I have changed dozens of them. It seems that usually it's the upper crank seal, however, so it's not too bad of a job to remove the seal with a small self-tapping screw. I have an extra long bit with a heavier shank which I drill a small hole in the seal after providing a protective wrap on the crankshaft with a piece of aluminum or thin tin. There are tools available to remove the seal but I have gotten by without one all these years.
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Yea, my mind was drifting that way, BO seals. I hope not. But if it is easy peasy change. The sneeze seems to stay even after changing the low speed mix rich or lean. 1/8 turn too lean and dies with no warning. Where as usually i get the "lean stumble rough" then dies. I adjust mix then adjust idle speed down, will run nice then start to sneeze/cough and die, lean or rich.... No mellow spot unless i run 1000 rpm or higher.. Would like to get it to crawl along, maybe asking too much... Rubber exhaust seal at mid point appears fine, but have not dug that deep yet. Runs the same with cover on or off, in or out of a barrel is the same. Runs great just above idle, mid range and top end. Tops at 11 mph. I will keep digging. Hope to post pictures soon too.
 
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well----11 mph on 40' yacht would be good.-----How big is this boat?----Are you sure it is running on 2 cylinders?
 
Took it out tonight again. Is currently on my 1970's 12ft Lund Car topper. It is light, but goes through the water like a snow plow, but will plane out. Not to concerned with top speed, but needs to troll low, slow and smooth for my dad. His boat is the crestliner version of mine. Had a backup 9.9 in boat, plus wife, myself and two chihouhouas. I will double check each cylinder by pulling a wire off at all rpm ranges. It has i'm guessing original points, condensers and coils. All look in great shape. Looked for cracks in all the wires but none seen. Will mist with water like we used to with cars and see if it trips up. Has purple coils if that matters. Spark jumps 3/8", nice crisp blue snap. Plugs on white side of tan, lean?
I have a inline fuel filter on it, but it seems dry at idle. Full at higher rpms. Looking like that maybe culprit. Will tilt filter when running and look for bubbles. Fuel hose has Evinrude connectors at the motor, aftermarket at tank. Causes no issues on my other 9.9 or with adaptors the junkyard Mercury 20hp. So kinda ruling that out for now. Pulled the hood off and rpm's went a bit up, but still faltered. I do have a failed front rubber motor mount that I will have to fix. Took a short video of the hood off.
 
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The crank seals are my guess. Got a box of em here. If you can get it to run on one cylinder, you might isolate whether or not it's the upper seal, or lower seal. I have a 9.5 here that I changed the upper only. Sold it to a guy in WI. Then he brought it back after about 2 trips out. I found out the lower seal failed too. It's still here 3 years later, he never picked it up. He watches auctions and Craig's List. He LOVES outboards. His last name is Rude.....named one of his son's "Evin".
 
Dug in a bit tonight, ran in deep tub in driveway. Made progress. Checked each cyl by pulling wire off. Checked out good. Compression is abouts 55-60 with my old tester. Need to get a new one. Went through fuel pump, rebuilt it. Checked hose connections, all were good and not leaking. Except the main one inside the plastic tank. Fixed that one. No more dry fuel line. 99% of the sneeze went away. Carb kit arrives tomarrow, will rebuild as the idle does wander a bit. I do have to tackle the upper front motor mount repair, will be following Tim's advice and change the 52 year old main crank seals. Never would have thought to check the tank pickup line for leaks. Learned something new.
 
How is your float? Not sure if they are available anymore. Still need that shifter handle and low speed mixture cable? Are you talking about that rubber mount under the turn tensioner?
 
Well, took a bit longer than expected, but got the 9.5 back together. Ended up buying a NOS upper mount. Shift boot in lower end was all but gone. Bought one for a Merc and cut it down to fit. Works great! Placed it in where the old boot was and used the original plate to clamp it down tight.
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Installed new main seals and that cured the low idle sneeze. New Solas prop and will be good to go for my dad. Nice quite low purr now!
 
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