'70s 9.9 Johnson - Fuel Intake & Gear Slippage

[PutPut1]

Hello,

I've got a 9.9hp Johnson, either a '74 or '76 I can't remember and have two problems with it.

First problem. When I go to start it I have to remove a plug and put some fuel in a cylinder otherwise it will not start. Carb is clean, bulb is pumped until firm. As long as I leave the fuel hooked up it will re-start all day long. If I let it sit for a day or two or disconnect the fuel line I have to repeat the manual priming. How can I fix this?

Second problem. When in gear, usually the faster I go the more it happens, it will pop out of gear (but shifter stays in gear) and the motor will rev up. I idle the throttle back, shift into neutral then back into gear and carry on. What's the problem here? Also, I'm not sure if this relates but the throttle twist grip is way off. First 1/4 to 1/2 of the turn is nearly useless, I can't seem to adjust it properly.

Any and all help is appreciated so thank you in advance.

 

[racerone]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

A number of thing to check.------Does the choke flapper close fully when you pull the knob out ?----Does spark jump a gap of 5/16" or more ?-----Jumping out of gear could be as simple as the hub in the prop slipping.----Try another prop.

 

[boobie]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

Or the clutch dog and forward gear.

 

[PutPut1]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

I'll go back and look but as far as I know the flap closes fully. I'm not sure about the spark. What is the best way to check that?

I could look into getting another prop. If that's not it, how difficult is replacing the clutch dog and forward gear? I'm decently mechanically inclined but if it means a complete tear down I'd have to take it in.

Thanks

 

[kbait]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

Search 'spun prop' in this forum.. you can test your current prop before dishing out cash on another one..

Good luck!

 

[steelespike]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

popping out of gear doesn't sound like a classic bad clutch dog seems more like the detent balls and spring in the gearcase maybe bad or missing. These are sometimes lost when it is taken apart for repair.
As far as the throttle is concerned put it in gear with the motor off and operate the throttle while observing the components.
Probably worn components in there somewhere.

 

[racerone]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

Do the spring and balls hold the clutch dog in gear or are they there for a " positive " nuetral ?

 

[boobie]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

If I remember right they helped hold the dog in gear, but I may be wrong.

 

[racerone]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

Well, I think the grooves in the clutch dog are only in the middle so that would help hold it in nuetral.-----They do help in making sure that the shifting is done in a " quick manner " from nuetral to forward and from nuetral to reverse.

 

[PutPut1]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

Alright I took the prop off. The grooves on it and the shaft look really good so I don't think that would be slipping.

If I want to get at the clutch dog, detent balls, etc, do I have to remove the lower unit? Or will it slide out when I remove the two bolts behind the prop?

 

[racerone]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

There is a rubber drive hub inside the prop.----You likely can not see it.---I used to have a prop cut apart just to show bewildered owners this very fact.

 

[PutPut1]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

Interesting. So this is what can slip then, not the grooves?

Going back to the throttle, something I notice is that first bit of turn I mentioned in my first post does nothing, just because of worn parts I think. But when the plate under the flywheel actually starts to turn it turns quite a ways before it even hits the throttle lever on the carb. The arrow on the plate is not lined up with the lever but I can't figure out how to adjust it. I know there's those couple bolts on the top of the plate and under the flywheel but they're hard to get at and it doesn't look like they'd provide enough adjustment.

 

[PutPut1]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

After looking at a few other threads and some Google recon, I'm wondering if I found something. When I remove my prop, I take the pin out, take the nut and washer out then slide the prop off. On the other side of the prop there is what I thought was another washer, but I'm wondering if it's actually the spun piece. Or is there supposed to be a washer there?

 

[racerone]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

That would be a thrust washer and it is a seperate piece that needs to be there.----------Please note he rubber drive hub it is inside the prop.

 

[Putzaroni1]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

PutPut1,
That totally sounds like a spun prop and like racerone says, it can't be seen. I was downstream on the Fraser River when I first dealt with this with my entire family. Thankfully someone pulled us back to the launch. I could go just a little faster than idle and it worked fine. Every time I tried to put a little more throttle to it, it sounded like a car clutch sounds when it's slipping. I replaced the prop and the problem was solved.

 

[PutPut1]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

If you guys are right that sounds awesome because getting into the gears doesn't sound like something I want to do. I drive by the Johnson/Evinrude shop around here quite a bit so maybe I'll just take the prop in. Although we've got a few feet of ice on the water so I won't be needing it for a while. Thanks for the help.

For my fuel delivery problem I'll go through the carb again. If fuel is getting to the carb I don't see why it wouldn't go to the cylinders unless there was a blockage.

racerone, you mentioned checking spark for a 5/16" jump. Is the easiest way to test this simply to pull the plugs then pull the cord and watch for spark?

 

[racerone]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

NO---Laying the plugs on the block is not a reliable spark intensity test.------You need to get or make a proper spark tester.------Piece of plywood / some wire /clip / staples etc..Once you see it at your friendly dealer you might say " I can make that "

 

[Putzaroni1]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

PutPut1,
I bought one of these and it works pretty good but you could build one if you wanted to.
Lisle 50850 Ignition Spark Tester : Amazon.com : Automotive

 

[PutPut1]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

That looks pretty simple. I could likely make one but of they're that cheap I could just buy. Thanks a lot for all your help guys.

Regarding my throttle settings, is there any insight? Perhaps I should post this in its own thread with some pictures.

 

[dazk14]

Re: '70s 9.9 Johnson - Fuel Intake & Gear Slippage

You have a neutral throttle limit. This can be adjusted by the shift lock on the stbd side of motor. There are 2 screws that can be loosened, then move the lock to allow more movement, then re-tighten. The concern is it may over-rev in neutral if not paying attention, but on older motors, the extra neutral throttle can help dramatically to get 'em started.

You are likely not actually opening the throttle, or very little. That will cause hard starting, especially when cold.

You need to do a link and sync.. With normal wear, The twist grip throttle will rotate, but further down the line, the wear and slop will not move adequately for starting. I am giving you a work-around for normal wear that is generally too pricey and not necessary for a serviceable rig.

That is done via the cam you mentioned and you need a thin wrench to loosen the 2 small bolts. The throttle should just begin to open when the mark lines up with the center of throttle cam...AND

the other end of the cam (high side) should force the carb throttle open fully when twist grip is rotated to max.

Note, the throttle plate is fully open when the small spring pin on the exterior of the throttle shaft is Vertical to the motor. It can be rotated past vertical, but you begin to close the opening, lowering power!

This usually requires a few attempts, and sometimes slightly less than perfectly vertical is all you'll get and have negligible affect on power. You can dremel, the cam slots slightly, if it bugs you enough...or just post a pic and I will tell u if you are close enough to not effect max power.

That ought to confuse you enough for now. Post the model # and we'll tell you the year.