1964 Evinrude 9.5 hard starting

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Rodnocker

Member
Joined
Dec 2, 2009
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Location
Clayton, NC
First... the history...
I bought this from my boss, who had bought it from someone on CL about a year prior but had never used it. I have it on a 14' semi-v aluminum boat that is 48" across at the transom. My first trip out two weeks ago resulted in the following. Very hard to start. Turns over ok, just did not want to fire. Priming bulb primed and tight, fuel tank valve open so it doesn't form a vacuum, and it took about 10-15 minutes before I could finally get it to start. to the point that I had blisters on my hand and had frayed the pull start rope. Once I got it started the first time though... I could cut if off and crank it with one pull. I head down the lake and can only get about 4.5mph and the boat will not plane out. I realize that all my weight is in the back of the boat (245lbs of me, 6 gallons of gas, motor, trolling motor and battery). I moved the battery to the front of the boat and it seemed to help a little. I was able to get up to about 6.5mph but still far from plane.

What I did...
I replaced the starter rope and found a hardened fuel line so I replaced that also. I found out that my motor should use champion j4j spark plugs but they don't make those anymore. They were replaced by j4c but I could not find those local. I found where someone is using j6c on the same motor I have but I could only find 1 local and I wanted to replace both (two cylinder). I finally found online where j8c's would work and I got those, gapped them at .030 per manual and put those in. I am running new fuel mixed 24:1 and 8oz of seafoam to 6 gallons of gas.

Next run...
I took the boat out this past Sunday. Still... very hard to crank. I primed the bulb until it was tight. I spent the next 50-75 pulls trying to crank it and it finally caught about 10 minutes later. For the rest of the day, it would only take one easy pull and it would fire right up. I even anchored to fish in one spot for about an hour, and it just took one easy pull and fired right up with no problem. Once I got it fired up... I was able to get up to 15.5mph and planed out nicely so I think the sparkplugs helped there.

My two issues are these.
1. Why is it so hard to start the first time? Could I be flooding it out by priming it to much?

2. When I go from idle to WOT (either slow or fast), it sounds like it has a hesitation, almost like it is missing a random spark, then it will finally clear (about 10-20 seconds) and smooth out and run fine.

Any help with these two issues would be greatly appreciated.
 
Rodnocker said:
First... the history...
I bought this from my boss, who had bought it from someone on CL about a year prior but had never used it. I have it on a 14' semi-v aluminum boat that is 48" across at the transom. My first trip out two weeks ago resulted in the following. Very hard to start. Turns over ok, just did not want to fire. Priming bulb primed and tight, fuel tank valve open so it doesn't form a vacuum, and it took about 10-15 minutes before I could finally get it to start. to the point that I had blisters on my hand and had frayed the pull start rope. Once I got it started the first time though... I could cut if off and crank it with one pull. I head down the lake and can only get about 4.5mph and the boat will not plane out. I realize that all my weight is in the back of the boat (245lbs of me, 6 gallons of gas, motor, trolling motor and battery). I moved the battery to the front of the boat and it seemed to help a little. I was able to get up to about 6.5mph but still far from plane.

What I did...
I replaced the starter rope and found a hardened fuel line so I replaced that also. I found out that my motor should use champion j4j spark plugs but they don't make those anymore. They were replaced by j4c but I could not find those local. I found where someone is using j6c on the same motor I have but I could only find 1 local and I wanted to replace both (two cylinder). I finally found online where j8c's would work and I got those, gapped them at .030 per manual and put those in. I am running new fuel mixed 24:1 and 8oz of seafoam to 6 gallons of gas.

Next run...
I took the boat out this past Sunday. Still... very hard to crank. I primed the bulb until it was tight. I spent the next 50-75 pulls trying to crank it and it finally caught about 10 minutes later. For the rest of the day, it would only take one easy pull and it would fire right up. I even anchored to fish in one spot for about an hour, and it just took one easy pull and fired right up with no problem. Once I got it fired up... I was able to get up to 15.5mph and planed out nicely so I think the sparkplugs helped there.

My two issues are these.
1. Why is it so hard to start the first time? Could I be flooding it out by priming it to much?

2. When I go from idle to WOT (either slow or fast), it sounds like it has a hesitation, almost like it is missing a random spark, then it will finally clear (about 10-20 seconds) and smooth out and run fine.

Any help with these two issues would be greatly appreciated.

- It could be that it is hard to start, because you may have low compression. But low compression motors sometimes perform well at higher speeds. (Because of the way the starter is position and the low profile of the motor, makes the pulling the starter low impact.....so it not uncommon to have low normal compression in the 60 and 70psi with this specific motor.

- I see that you changed your plugs and you added seafoam to the tank of gas. As you run the seafoam it will help loosen and dissolve the coking and carbon build on the piston and ring and may improve your compression. Your WOT(wide open throttle) improves significantly from about 4.5 to 6mph to 15mph. (15mph is about the max you will get with this motor...which is good).

- Carb cleaning and kit couldn't hurt and may help. High speed jet may have some junk in there.
The 9.5hp motor can be a little difficult to work on but dependable when service appropriately.

I am going to make a suggestion.......and this is no disrespect to this very good site, but you might need more guidance from specific 9.5hp experts. Iboats.com has few very good experts (retired and still active mechanics) that have really worked on these motors and know them very well. They help me rebuild one of my 9.5hp motors.

Here is a link directly to there Johnson/Evinrude posting section.

https://forums.iboats.com/forumdisplay.php?f=24

You would register just as you would for this site and it is free to join just like this site. When you post the above information supply the model number, year of motor and its 9.5hp. Just copy and paste the above information you supplied on this site instead of retyping everything...plus (model number, year of motor and its 9.5hp at the top). If a day goes by and you get no nibble (alot of traffic on that forum)....post a reply and put bump it will place the post back at the top of list, so someone can see it.

Couple of experts are Ezeke, FR, Rick, BetheKing, and couple of more I can't remember. Oh, if you plan on keeping this motor and working on it, I would suggest getting a specific service manual for this motor...ebay is good place. This motor is compact and it is different from most of the carb makes of the Evinrude and Johnson of that era.

https://cgi.ebay.com/ebaymotors/EVINRUDE-1964-64-9-5-HP-SERVICE-MANUAL-CD-_W0QQcmdZViewItemQQhashZitem3ef25ff402QQitemZ270354347010QQptZMotorsQ5fManualsQ5fLiterature

Here a link to a parts breakdown of your motor.

https://www.marineengine.com/parts/vintage-evinrude-johnson/278540/catalog.html?https://www.marineengine.com/parts/vintage-evinrude-johnson/278540/27854000001.htm

Good luck
 
Thank you cajuncook1, already getting some good responses there. I have already found the carb kit locally and will pick it up tomorrow. Was also advised to use either j4c or j6c plugs instead of the j8c that I was told would work (to hot for my motor) and will be changing my mix to 50:1.

Thanks to this site... I have the manual for the motor (the second sticky that shows the public link to manuals).

I hope to be starting a thread this winter for the changes I make to the boat. Not going to interrupt my fishing with putting in floors yet though.
 
And the results are in...

I cleaned the carb by soaking it overnight in Goop carb cleaner and then rebuilt it the next day. I changed the champion j8c plugs to j6c. I took the boat back out and it ran great. Started on second pull (instead of 60th) and ran out great. I did loose about about 2mph (15.5mph to 13.3mph)... I'm guessing that is from the spark plug change. If it will make the motor last longer though, I have no problem with that.
 
Cool, glad to hear you got the motor running better. Like I stated, your size boat and equipment, 15mph will be about the best it will deliver. 13mph could be going against current, wind or extra equipment. You could try adjusting your motor tilt (example going from the second to 3rd hole away from the transom) to see if you get better planing and speed. When it is just me in the boat with my fishing stuff then I have the tilt of the motor in the second pin hole from the transom. When my brother is with me, I find I get better planing and speed if I move it back to 3 hole from the transom on the motor tilt bracket. When my brother is with me the speed is also reduced to about 11mph. Just play with the setting and see what is to your liking.

I have a 1965 (was parts motor, but I decided to rebuild it) and 1971 Evinrude 9.5hp motors

Some of my other motors are:

1984 15hp Evinrude
1970 18hp Evinrude
1968 6hp Evinrude
1967 6hp Evinrude
1972 2hp Johnson
1957 3hp Evinrude

Most recently purchased for rebuild is 1955 7.5hp Evinrude

Good luck buddy and happy fishing
 

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