starting and takeoff issues 1985 johnson 20 hp

[pafree]

we took the boat out last week. a little cold but over all nice day. i had rebuilt the carb and fuel pump this fall and thought i had everything set up. the first start up went great at the boat ramp and since this was the first time i the water (salt) then i knew i had to adjust the idle screw. we cruised up the the bayou and the engine ran great and even got my wide 14 up on plane. we stopped to fish for a bit but the fish were not bitting. i went to start the engine but it acted like it was flooded. we anchored back up and let it sit and then tried again and the engine fired up. this happened a couple of times again. the other issue was you had to gun the throttle a bit to get it to go in gear or it would bog and try to die. 1985 johnson 20 hp primer/choke. could it be the cold making it act stupid by not being warmed up all the way? i had the cover off one of the times to adjust the idle screw and it worked fine so could the engine not be getting enough fresh air to carb (are there vent hole in the cover somewhere?)

 

[MrSimon]

Definitely sounds like a carb/idle adjustment issue.

If you are handy and so inclined, you could take it home and start fiddling with different settings of the screws until you get it just right.

Or you could do what I do and take it to a reputable shop and have a pro dial it in. I've given up messing with finicky carbs years ago.

 

[pafree]

If you are handy and so inclined, you could take it home and start fiddling with different settings of the screws until you get it just right.
.

i like to piddle and a day set a side to mess with the engine on the water would be fun. when i messed with old VW's, there was a summer setting and winter setting. is it the same with a outboard?

before this trip i had the engine idling smooth with the earmuffs but it needed turned up when i put the engine/boat in the water and it ran fast on the earmuffs when we were flushing the engine.

 

[MDCrappie]

i like to piddle and a day set a side to mess with the engine on the water would be fun. when i messed with old VW's, there was a summer setting and winter setting. is it the same with a outboard?

Nope - same setting.

If you get the motor tuned perfect with cowling off, then it cuts out when you put the cowling on there is a chance you have an exhaust leak under the cowling.

In ref to reving the throttle - does the motor "Bog" (rpm drop slightly) then take off" of does it "sputter" (rpm seems to stay the same while "stumbling and sputtering") and then take off? ? When described as a "bog" is is usually too lean, when it sputters it's too rich.

 

[pafree]

MDCrappie » 02 Jan 2014, 21:25[/url]"][
In ref to reving the throttle - does the motor "Bog" (rpm drop slightly) then take off" of does it "sputter" (rpm seems to stay the same while "stumbling and sputtering") and then take off? ? When described as a "bog" is is usually too lean, when it sputters it's too rich.

by your definiton then it is lean. if you turn the throttle slowly to increase the RPMs then it would "hesitate/cut out" but if you "punch it" then the motor would take off and run like a beast.

when i put the carb kit in the carb, i took the screw out that controls the throttle wing. i couldn't remember exactly how open the wing should be but did have it open too far at first but closed it down. could i have it closes too much now?

 

[MDCrappie]

pafree » Thu Jan 02, 2014 10:04 pm[/url]"]

when i put the carb kit in the carb, i took the screw out that controls the throttle wing. i couldn't remember exactly how open the wing should be but did have it open too far at first but closed it down. could i have it closes too much now?

Screw that controls "throttle wing"? Pretty sure what you are talking about controls the sync/lync for the timing/carb adjustment. That could definitely be your problem.

The mixture screw is on the front of the carb over top of the throat.

In the below diagraham "29" is the knob you adjust for mixture. Are you moving "15"? If so you really need to get a Seloc, or Clymer manual for your motor. I've got the manual for the newer motors, but not yours so I'm not sure of the exact adjustment. Right now you are either getting gas too early or advancing timing too early.

https://www.boats.net/parts/search/BRP/JOHNSON/1985/J20CRCOS/CARBURETOR/parts.html

 

[pafree]

MDCrappie » 03 Jan 2014, 16:05[/url]"][
In the below diagraham "29" is the knob you adjust for mixture. Are you moving "15"? If so you really need to get a Seloc, or Clymer manual for your motor. I've got the manual for the newer motors, but not yours so I'm not sure of the exact adjustment. Right now you are either getting gas too early or advancing timing too early.

https://www.boats.net/parts/search/BRP/JOHNSON/1985/J20CRCOS/CARBURETOR/parts.html

i was adjusting "29" out on the water. "15" is the one i am not sure is 100 percent set correctly. i got manuals from this forum and have read through most of them but wasn't sure if there was a home remedy way of setting it. example: on a old vw distributor, you can use your drivers lic. to set the gap if you have to change the points on the side of the road.

 

[MDCrappie]

pafree » Fri Jan 03, 2014 7:06 pm[/url]"] i got manuals from this forum and have read through most of them but wasn't sure if there was a home remedy way of setting it. example: on a old vw distributor, you can use your drivers lic. to set the gap if you have to change the points on the side of the road.

You really need to use the manual to set the Lynk/Synk. You can adjust 29 on the water, but not the others.