1994 Johnson 150 HP bogging after 1/2 throttle

[stratosguyTN]

I have a 1994 Johnson 150HP Fast Strike that idles perfectly but is having trouble coming out of the hole. Yesterday for example, I left the boat ramp and it came out of the hole with somewhat of a brief hesitation. After it comes out of the hole, it runs great on top end. Fished around for about an hour, and then went to take off and it wouldnt come out of the hole at all. After 1/2 throttle, it bog down and try to die. After 3 attempts, with milking the throttle, it came out of the hole and ran great. Another example - when trying to load the boat on the trailer, motor trimmed up 3/4 ways, it also tries to stall when giving more than 1/2 throttle. This happens every time. New spark plugs, new power pack, oil/gas ratio 50:1 and VRO is disabled with all appropriate lines blocked. Any ideas?

 

[stratosguyTN]

Re: 1994 Johnson 150 HP bogging after 1/2 throttle

I have a 1994 Johnson 150HP Fast Strike that idles perfectly but is having trouble coming out of the hole. Yesterday for example, I left the boat ramp and it came out of the hole with somewhat of a brief hesitation. After it comes out of the hole, it runs great on top end. Fished around for about an hour, and then went to take off and it wouldnt come out of the hole at all. After 1/2 throttle, it bog down and try to die. After 3 attempts, with milking the throttle, it came out of the hole and ran great. Another example - when trying to load the boat on the trailer, motor trimmed up 3/4 ways, it also tries to stall when giving more than 1/2 throttle. This happens every time. New spark plugs, new power pack, oil/gas ratio 50:1 and VRO is disabled with all appropriate lines blocked. Any ideas?



***After doing more research on the motor, if you pump up the primer ball to tight, you hear a hissing bubbling noise. According to the Manufacture, the part identified is the vapor seperator. There is no gasket; it appears as if someone tried to use silicone or some other sealer in place of the gasket. Could this be it?

 

[emoney]

Re: 1994 Johnson 150 HP bogging after 1/2 throttle

That could be it. It could also be a fuel pump diaphragm issue, or related. Could also be a bad fuel line or something in the fuel tank vent restricting it. Then again, it could also be a clogged high speed jet in the carb.

 

[stratosguyTN]

Re: 1994 Johnson 150 HP bogging after 1/2 throttle

I just removed the vapor seperator and there is no "gasket" but there is a rubber piece on the bottom. It doesnt appear to be a gasket in anyway, however it may have been when it was new. Question is - when giving it full throttle, does it quickly remove the fuel from this seperator? Because there is a good size reservoir to where the gasket is missing. If it does remove the fuel quickly, then it may be sucking air into this in which it shouldnt.

 

[stratosguyTN]

Re: 1994 Johnson 150 HP bogging after 1/2 throttle

I went to my local dealer and bought a new vapor seperator gasket, fuel filter, and fuel filter O-Ring. Installed all of it, tested for leaks (none now) then started it. It started and ran (out of the water) like it normally does - perfect. So, Im gonna carry it to the lake in the next few days and try it out. However, the primer bulb still will not stay firm longer than about 5 seconds after priming. Fuel isnt leaking out of the carbs anywhere so should I get a new primer bulb?

 

[glenn property of pam]

Re: 1994 Johnson 150 HP bogging after 1/2 throttle

make sure the electric choke red lever is pointing in the correct direction. i had a simular problem last month when i changed my plugs i guess i caught the lever and had it half open. if the bulb wont stay firm you have a problem that you will have to narrow down and fix. pull the gas line off the pump and plug with a bolt then pump it up if it fails then the bulb is bad.

 

[stratosguyTN]

Re: 1994 Johnson 150 HP bogging after 1/2 throttle

Just took it to the lake and it ran like a champ! Hole shot was great and never had any hesitation. Moral of the story - make sure there are no air leaks in the fuel system or you will be putt putting around!