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1977 Johnson 15hp

Typically the idle stop unit fails because the cir-clip (inner end) of the adjusting knob breaks its shoulder off that holds the clip which no longer keeps the unit in place. For me, I know how to modify the unit to work again, actually improving on the design and operational life of it. Instead, shops throw the parts away and put in a new unit. Ridiculous. Anyway, this is what you need to properly set the idle and help yourself reference the correct starting position to adjust your throttle cable effectively.
 
timguy said:
Typically the idle stop unit fails because the cir-clip (inner end) of the adjusting knob breaks its shoulder off that holds the clip which no longer keeps the unit in place. For me, I know how to modify the unit to work again, actually improving on the design and operational life of it. Instead, shops throw the parts away and put in a new unit. Ridiculous. Anyway, this is what you need to properly set the idle and help yourself reference the correct starting position to adjust your throttle cable effectively.
Click to expand...

So looks to me like I need everything ! But what exactly do I need???? I wish you were little closer Tim !!:)

So today I was starting the motor after adjusting the cam and greasing this and that.
Still had to push down the cam follower to start the motor, but it did start. Latter on i discovered that I forgot to use a choke.....( I did get new choke grummet , so is nice and firm now). I let motor to idle to warm up.....at some point motor died. Spend quite few minutes trying to start it back up......no luck. Cleaned spark plugs. Nothing. Then I realised that I did not hook up gas line ........nice Wojo...
With gas supply, motor started and I had it running for few minutes, shifting to forward gear and back Then turned motor off and on few times, and everything was working good. I did checked spark plugs after that and seems that lower cylinder had the plug little wet in comparison with the top one......maybe I should get new plugs, just in case??
Well, I feel like I can put the boat in the water this coming weekend and should run.
If this 15 HP will be good enough for this boat I would like to go over it in the winter and make it look and run as it should.
Thank you everyone for your help!!!

Wojo

Fela 14.jpg
 
Okay, good idea. So I noticed you have no provisions for electronically stopping the motor from your control center, right? So if you implement an idle or throttle stop, you should set up a remote kill switch to be safe. You can't be running back to hit that kill button on the motor in an emergency. The way you would shut down now is to just close the throttle. The problem with that is something that alot of techs or operators don't really take note of. What is that you say? If you shut down using the throttle, what are you doing? Your mostly running it out of fuel.......cylinders nearly dry, right. (You stopped it by retarding the timing and it "slows" to a stop, loosing much of its ability to recharge the cylinders). So it takes a bit more cranking to get fuel in and fire back up, right? If you are running and shut down with a kill switch, you are stopping the SPARK which leaves a "ready charge" of fuel in the cylinders. The result is.......an immediate fire when you hit the starter........fuel charge and spark are "right there"........your motor is running at the "touch" of the starter. I have noticed this for years as a guide. When you leave your throttle set at idle....hit the kill button, net the fish, or whatever. You pull the starter cord not even 1 foot and its running again. I think that the 6 horsepowers, for instance, came out with a kill button after only a few years, because the OMC techs figured this out.
 
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well, got the boat in the water. Got the motor to start and run the boat from the boat ramp to the buey in front of my house. Motor was running great, but after I got home I shut it off for a minute or two and after that I could not start again - smelled gas - I hit the starter only few times and decided to row the boat to the buey.
Good part is that the HP is enough for my boat but lack of reliability is troubling. I think this is all due to idle situation.

Fela19.jpg
 
Did you hook up your idle stop device in the port side opening there in the lower cowling? Beautiful rig, brother. Longshaft motor too. I will build one just like that for my wife's 20" transom boat. All my 15's here at the house are shortshaft. Repairing these 9.9/15's is fun for me. Make sure that your transom measures no more than 21 inches full height where the motor is mounted. I notice a great distance there when I look at the photo.
 
thank you Tim.
Not sure what the transom height is, but the water pump is working very well, strong stream of water is coming out. I like this 15 HP so much better than 7.5 HP I had on it last year, much faster. Need to move seats little more forward to balance the boat. I did not get the boat on the plane yesterday.
I don't have the idle stop yet. Looking for used one, and will price all new components today.
I would love to get a rebuilded 15HP that runs perfectly, because I feel this is the HP for this boat........recommended by the designer too :D.
Just so you know, this boat came with plans, where 7.5 HP was recommended.....then I found out that newer the same boat plans are recommending 15 HP. Now I have 7.5 HP long shaft motor sitting in the shop :)
 
checked with them via email and they told me that if I am using remote controls I do not need it.
I am confused as far...... what do I need???
 
They are mistaken, there is way too much movement in cables to accurately control idle. Take for instance when you turn the motor all the way in one direction the cable will move slightly I have never seen that not to be the case therefore it will change your idle speed. There is no effective way to control accurate idle speed without a positive stop on the motor whether you have cables or not.
 
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