70hp johnson stalls on throttle up

T

tracker14437

Seaman Apprentice
Joined
May 11, 2002
Messages
30
2000 70hp johnson j70plss<br />read a lot of post and have manual.<br />i did synchronization and linkage adjustment,<br />new gas filter and plugs,<br />gas lines are clear, new primer bulb (omc).<br />just cleaned and rebuilt all 3 carbs.<br />set idle timing on the water in gear with timimg light to 4 degrees atdc, is this right?<br /><br />will go into gear ok then stalls on throttle up. <br />runs great above 1500rpms<br />anything else to check?<br /><br />thankyou
 
O

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: 70hp johnson stalls on throttle up

Before it stalls on throttle up,try repeatedly bumping the fuel primer button in on the ignition switch and see if engine picks up.If so, your idle mix circuit is restricted or you need to richen the idle mix.
 
T

tracker14437

Seaman Apprentice
Joined
May 11, 2002
Messages
30
Re: 70hp johnson stalls on throttle up

thanks OB<br /><br />its going to be a few days before i get back on the water and give this a try I will post the results
 
T

tracker14437

Seaman Apprentice
Joined
May 11, 2002
Messages
30
Re: 70hp johnson stalls on throttle up

got back out tonight motor ran good until i shut it off for a few minutes then starts ok but still cuts out when put in gear. priming at cut out gave it more power and kept it from stalling. adjusted low idle screws no help runs the same<br /><br />any help appreciated
 
O

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: 70hp johnson stalls on throttle up

Still sounds indicative of carburetor low speed circuit restriction or too lean of idle mix.How many turns out are your mix screws opened?You can determine exactly on each one by turning them in (clockwise) until they lightly seat and counting the turns it took.To restore to original position just do the reverse.
 
T

tracker14437

Seaman Apprentice
Joined
May 11, 2002
Messages
30
Re: 70hp johnson stalls on throttle up

hello ob<br /><br />they were 2 3/4 out after rebuild now 3 turns out
 
M

Mark R Groves

Seaman Apprentice
Joined
Dec 5, 2001
Messages
45
Re: 70hp johnson stalls on throttle up

How is your idle speed? Maybe it's set too low. After I rebuilt my carbs on my Evinrude 40 (which is basically the equivalent motor to yours minus one cylinder) a couple of years ago I had a similar problem. I had set the idle to 750rpm as specified by OMC. However, I found when I ran the motor after the rebuild I'd experience frequent stalling when the motor was shifted into forward or reverse. Eventually, I decided to tweak the idle speed up to about 1000rpm... problem fixed. You may want to try this on your motor.<br /><br />MG
 
W

wuzafed

Seaman
Joined
Aug 14, 2003
Messages
67
Re: 70hp johnson stalls on throttle up

Before you really nuts, like I did some time back, CHECK YOU FUEL SUPPLY!!! I put in a bad tank of fuel that had water in it. Every time I would get the boat about on plane the water would kick in and shut the system down. With the fuel pick up in the stern of the tank, the water would go the stern as the bow picked up and the motor sucked it in and shut down!!! Got the water out and she ran great again. Just a thought....
 
T

tracker14437

Seaman Apprentice
Joined
May 11, 2002
Messages
30
Re: 70hp johnson stalls on throttle up

took boat to shop they say fuel pump could this be it.
 
rickdb1boat

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: 70hp johnson stalls on throttle up

tracker14437 <br /><br />If you pump the bulb up firm and try to accelerate, does it still bog out? If so, sounds like OB is on with the low speed circuit restriction. Sounds like it may be the float level is incorrect when you did the rebuild. 3 turns out is about right on the settings.
 
T

tracker14437

Seaman Apprentice
Joined
May 11, 2002
Messages
30
Re: 70hp johnson stalls on throttle up

Sorry it took so long to get back. Tech at shop spent a lot of time trying to fix motor.<br />Finally came up with sync & link. When setting throttle lever against idle stop screw (332012 not adj.)and setting all linkage, the spark advance lever was to far away to move the timing base assembly at the same time as carb linkage. He could not adj. the linkage. He put same set up that the wot screw stop has (screw, nut & spring) that is a longer screw to move spark advance lever closer to the timing base assy. and was able to adj. Motor runs fine now. :) <br />Dose this make scens ?<br /><br />Thanks for all the help everyone gave me
 
You must log in or register to reply here.
Top