4.5 johnson not opening up in water

vipper1413

Cadet
Joined
Aug 28, 2004
Messages
10
Hello i have a 1980 johnson 4.5 hp that runs in nutral good but when i put it in gear and put full throttle it dosent seem likes it's trying hard to go fast it just like stays at a low slow speed. just to mention the engine i just got going yesterday after about 15 years of not starting so if u can tell me anything to help thanks
 

Droll

Chief Petty Officer
Joined
Jul 30, 2003
Messages
514
Re: 4.5 johnson not opening up in water

What have you done to make it start ??<br />
after about 15 years of not starting
Before using this engine I would change impaller ,rubber will becomme harder and develupe cracks , better safe than sorry :) <br /><br />First thing to do , clean the carburator ,get a gasket kit .<br />Then use fresh gass ( premix 50:1 TCW-3 oil ).<br /><br />Adjust the carbs low speed jet ( 1.5 ?? turn out , check this one ,not shure )<br /><br />Does all the linkage ( carb/ignition ) move as it shuld ??<br />First 2/3 of engines rpm are controled by the ignition only , the carb will open at the last 1/3 .
 

vipper1413

Cadet
Joined
Aug 28, 2004
Messages
10
Re: 4.5 johnson not opening up in water

really all i did to make it start was clean it up check every thing and after about 100 pulls i got it going. i let it run for about 5 min then put it in gear it was doin good till i put full throttle. It didnt even want to try hard it just like idled along. the carb actully is brand new so i knew that was good. every thing works accept the wrist throttle is stripped so i used the carb by hand. still i have no clue y it wont open up in gear.
 

Droll

Chief Petty Officer
Joined
Jul 30, 2003
Messages
514
Re: 4.5 johnson not opening up in water

i used the carb by hand
Theres the problem . :) <br /><br />All outboard engines I have used (except an old zuki) there are a linkage between carburator and ignition .<br />When you turn the throttle ( wrist throttle ) you will turn the ignition first and when you reatch 2/3 off full throttle ,the carburator will start to open .<br /><br />By only opening the carb befor the ignition,the engine will die .
 

Paul Moir

Admiral
Joined
Nov 5, 2002
Messages
6,847
Re: 4.5 johnson not opening up in water

accept the wrist throttle is stripped so i used the carb by hand
.<br /><br />If you're not also advancing the spark with the carb opening, then the engine will fall on it's face like you described. The tiller arm also activates the spark advance, if you look into it.<br /><br />Get yourself a manual and replace the impeller. Those outboards are really excellent, and deserve the small amount of work to get them running again.<br /><br />EDIT: Pardon, Droll. :)
 

Droll

Chief Petty Officer
Joined
Jul 30, 2003
Messages
514
Re: 4.5 johnson not opening up in water

Follow Paul Moirs advice about the maual + NEW impaller <br /><br />
EDIT: Pardon, Droll.
:) thats ok , twice is better than none .
 

ED21

Master Chief Petty Officer
Joined
Aug 26, 2003
Messages
829
Re: 4.5 johnson not opening up in water

A manual expains how to synch the carb to the timing. It's easy to do, but I can't remember.<br />Ditto the impeller.<br />I would also check the fuel filter. It may be clogged.
 
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