55 johnson: questions and observations

breeze

Cadet
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Jun 9, 2007
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Ok, this is how today went: I removed the prop so I could run more WOT in my trash bucket. Bought 3 gallons of fresh gas and mixed 24:1, poured in with the old stuff and mixed well. Pulled the fuel filter and cleaned in fresh gas (didn't look bad to begin with. no sludge on it at all). Motor is an RDE17.

1) Starting. What is the best way to start this motor? I was really only able to get it to fire the first time by priming the cylinders with a little gas directly. Should I put the throttle up as far as it will go in neutral and choke till it starts? It seemed to crank and crank before I primed directly with no results. However, once I get it to start the first time, It will start everytime with the throttle up as far as it will go in neutral with no choke. then I just back it down.

2) Mixture screws. I have the low end adjusted so it will idle nice and smooth with very little smoke, if any at all. The high end screw kept moving richer with the motor vibrations the more i revved it (maybe it's trying to tell me something :D) I think i may have this temporarily fixed with a rubber washer I found in my shed to put a little friction between the knob and the face plate. I did this because I saw some rubber on the back of the adjusting knob that seems to set inside the back of the knob and it was worn away. I tried to lean this one out until there was almost no smoke, but then it would start knocking a bit. So I richened it back up. But then there was quite a bit of blue smoke from the oil, allthough it ran real strong. Questions are: how much should these motors smoke? and will the carb kit keep the high end knob from adjusting itself? Is it possible to run these motors at a lower oil ratio to alleviate some of the smoke and the slick they put out?

At the end of all this, I think I burned up several gallons of gas, the water in my barrel was a milky white color. Is this right? Sorry for the long post and all the questions, I'm just tryn' to cover all my bases before I get it out on the water.:cool:
 

tmcalavy

Rear Admiral
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Aug 29, 2001
Messages
4,005
Re: 55 johnson: questions and observations

Oil+Water+Prop in confined space = milky water, completely normal. Sounds like you found the sweet spot for each of the two needles. You're close but will have to adjust a little once out on the boat. The nuts around the high and low speed needles should be tight, with some kind of packing behind them...sounds like you improvised well. My FD-11 Johnson sea horse 18 starts best with throttle on Fast and choke closed, when cold, in neutral of course...after that I can start it with one pull without choke unless it sits a couple of hours. Yours will probably be similar after you get it adjusted.
 

wbeaton

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Jul 30, 2006
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2,332
Re: 55 johnson: questions and observations

"Should I put the throttle up as far as it will go in neutral and choke till it starts?"

That is normally how its done. Are you using the manual or electric choke? If the high speed needle is vibrating out then you should add a little more packing to the needle and retighten.

24:1 is the ratio. They do run smokey and leave a mess. I've recently switched to Amsoil at 24:1 and am having good results. No smoke or oily film left on the lake. I found I had to start with a fresh mix of Amsoil and gas. When I first mixed it there was a small amount of old pre-mix (conventional oil and gas) in tank and I found it still ran smokey because of it. Once I mixed a new tank with only Amsoil and gas it smokeless. However, I've only run about 2 gallons through two different motors so I'm not making any guarantees just yet.
 

steelespike

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Apr 26, 2002
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19,069
Re: 55 johnson: questions and observations

Don't get crazy trying to lean the mixture screws.Too lean on the idle screws and it will stumble when you hit the throttle.Too lean on the high speed can burn a piston.Pretty much impossible to adjust the high speed in a bucket.
And you risk a runaway when reving in a bucket.
These allways appear really smokey in a bucket.
 

JB

Honorary Moderator Emeritus
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Mar 25, 2001
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45,907
Re: 55 johnson: questions and observations

I don't bleeping believe what I think I just read!! :eek:

Someone correct me if I am wrong here.

Breeze just explained that he removed the prop so he could run his engine WOT with no load on it.

Then he explained how he set up the mixture to run fine with no load on it.

Is there any chance that the mixture set up that way will be correct when running with a load!!??

How lucky did he get in not going into runaway and blowing his engine to bits!?

Thank goodness Steelspike finally cautioned him about runnning WOT with no load, but it looks almost like an afterthought.

What have I been missing for 60 years here?:confused:
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 55 johnson: questions and observations

I read that comment about removing the prop too, and thought that either he didn't say what he meant to say, OR such ignorance didn't even deserve an answer.
 

BoatBuoy

Rear Admiral
Joined
May 29, 2004
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4,856
Re: 55 johnson: questions and observations

You mean he should have left the prop on when running wide open in a bucket?:D
 

wbeaton

Commander
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Jul 30, 2006
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2,332
Re: 55 johnson: questions and observations

"Thank goodness Steelspike finally cautioned him about runnning WOT with no load..."

Funny you should say that...Last time I mentioned that on a fishing board I got lambasted for it. Apparently, some "marine techs" recommend it.
 

breeze

Cadet
Joined
Jun 9, 2007
Messages
20
Re: 55 johnson: questions and observations

Wbeaton, it's a manual choke. What kind of packing do you mean to add? Can I remove those brass sleeves around the mixture screws without something falling apart? AS far as my mix goes, I'm mixing penzoil tcw3 with the gas. However I can't say what kind of oil was left in the tank when I started. It was about 1/2 full, so i'm still burning that out.

AS for the running WOT with no load, this was NOT done for any extended period of time. maybe 10 to 30 seconds max, if that. Actually, come to think of it, when I hit full WOT the rpm's sounded a little scary so i backed it right down. Thanks for cautioning me about doing this, I didn't know. Which is why I tried to be very specific about what I did so there is no misconception.
 

wbeaton

Commander
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Jul 30, 2006
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2,332
Re: 55 johnson: questions and observations

You can back out the packing nut and add packing without any problems. Packing comes as filbre washers in the carb rebuild kit. If you didn't buy a rebuild kit you could just use an o-ring. Slip it over the needle and screw the packing nut in.

Double check that your choke is working properly. I just fixed a 3 hp yesterday that had a broken choke so it does happen.
 

breeze

Cadet
Joined
Jun 9, 2007
Messages
20
Re: 55 johnson: questions and observations

Thanks for the info. I do have a carb kit ordered already. should be in sometime in the coming week.
 
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