77 85 hp Johson doesn't have full throttle

[trudat18]

I give it full throttle but it only goes up to 6-7 mph. Ive put new plugs, new fuel, new fuel line, battery. What seems to be the problem. ANY HELP PLEASE.

 

[rickdb1boat]

Re: 77 85 hp Johson doesn't have full throttle

Hey trudat<br /><br />Are you getting spark to all the plugs?

 

[Saskatoon2005]

Re: 77 85 hp Johson doesn't have full throttle

...spun hub? Everything could be going perfect but if the hub in the propeller is spun...not going to go too fast...

 

[Joe Reeves]

Re: 77 85 hp Johson doesn't have full throttle

You need to describe the problem in detail. Exactly what is the engine doing? What is the compression on all cylinders? With the plugs removed, does the spark jump a 7/16" gap as it should?<br /><br />What s/plugs are you using and what gap are you setting them at? When you apply throttle, do the rpms increase normally?<br /><br />Your present question as it stands is just about impossible to answer.

 

[trudat18]

Re: 77 85 hp Johson doesn't have full throttle

With it out of the water it seems to throttle up to the rev limiter. But I don't know if the prop is spun. The boat has been sitting for about 10 yrs. with no use. To check if I have spark should I Just pull the plugs when I'm at full throttle?

 

[trudat18]

Re: 77 85 hp Johson doesn't have full throttle

thanks for all the help i have since taken it out and it runs good for about 5 min then acts up and loses its power the fuel bulb is collapsing as well could this be the problem but it's brand new.

 

[ezeke]

Re: 77 85 hp Johson doesn't have full throttle

If the bulb collapsed, you have not opened the vent on the tank or something similar. Is the arrow on the primer bulb pointing to the engine end of the hose?<br /><br />If you are running from a portable tank that is on the ground, you should elevate it.

 

[tashasdaddy]

Re: 77 85 hp Johson doesn't have full throttle

you better use the red search function at the to of this page ans search for 'awakening a sleeping outboard' , do this before you turn that motor to toast. get a manual kencook.com did you mix your fuel with oil. i noticed your 18, how much experience have you had with motors, knowing this help us help you. i will need a new water pump impeller among other things after sitting for 10 years. get some one to help you check the spark, take the plug out one at the time, hold the wire, touch the engine, and get the helper to turn the key, NO,NO,NO, i mean take the plug out insert it back in the wire, hold with a pair of insulated pliers, have helper turn the key, ground the plug to the engine block and you should get a spark.. careful bare handed it will jolt you pretty good

 

[ezeke]

Re: 77 85 hp Johson doesn't have full throttle

You check for spark with all of the plugs out on this motor. (and see if you can get your helper to hold them. )<br /><br />This link shows Spark Testers some good testers here at Iboats

 

[trudat18]

Re: 77 85 hp Johson doesn't have full throttle

I have got spark to all of the cylinders.

 

[fireman57]

Re: 77 85 hp Johson doesn't have full throttle

A nice blue crisp spark or weak orange/yellow?

 

[wreckless]

Re: 77 85 hp Johson doesn't have full throttle

Remove carbs and completely clean/rebuild.

 

[trudat18]

Re: 77 85 hp Johson doesn't have full throttle

I took out the spring and ball bearing check valve on the tank and reattached the fittings works great the ball no longer collapses I also got a larger fitting to fit the hose properly. The only thing is I still and losing power to my engine after it warms up a little My 2 cylinders on the left if your looking at it from the back of the motor dont have spark. I checked the power pack there is 55 volts coming out of to the right cylinders with spark and only 40 volts going to the left cylinders without spark. I switched the wires on the power pack to make sure it wasn't the coils and I was able to get spark on the left side by hooking the wires up the the terminals that send the power to the right side. Any ideas on the problem. Or Where I can find a used or cheap power pack for that motor? Not only that I cant shift into reverse it goes into neutral and forward fine but it wont go into reverse at all seems like something has it jammed in the shifter control box. I removed all the linkage in the power head to make sure something back there wasn't jammed and it still wouldn't work. I am really losing faith in this project any ideas?

 

[tashasdaddy]

Re: 77 85 hp Johson doesn't have full throttle

can you shift it manually at the engine connection with the cable detached. if so you have a bad shift cable.

 

[trudat18]

Re: 77 85 hp Johson doesn't have full throttle

yes it shifts fine manually

 

[trudat18]

Re: 77 85 hp Johson doesn't have full throttle

How do I remove the cable in the shifter case? I took out the allen screw inside there and tried to pull it out but there still seems to be a pin restricting it.