1995 Johnson Fast Strike Fuel Pressure Problem

[stratosguyTN]

I have a '95 Johnson Fast Strike that slowly shut down on me while running full throttle. Here's some history: I purchased the boat about a year ago. It ran and started fine upon first crank. Leaving the ramp, it would come out of the hole perfectly with no hesitation. Once I would run to my first fishing hole and fished (about an hour) it would still start fine. Upon take off, it would bog down when you mash on it to come out of the hole. I got around this but pushing in the key (choke). Once, I pushed in the choke for a second or two, it would take right off and run like a champ. Now, unless I keep squeezing the primer bulb, it wont continue to run. Example: Squeeze bulb 4-5-6 times till its firm, start engine (starts fine), then after about 30 seconds, it spits sputters, and then dies. The primer bulb will be completely soft and I have to re-prime it for it to start back. Note: the bulb doesn't collapse and is less than a year old. If I keep squeezing the bulb as its running, it will keep idling just fine. I have troubleshot it enough to know its losing fuel pressure somehow. No fuel leaks are visible. I really don't think its the fuel tank or primer bulb. Need some help here as this is really weighing heavy on my mind.

 

[Will Bark]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Primer bulb is supposed to go soft as engine runs; it becomes just a part of the fuel line; you may want to look at rebuild of carbs.

 

[sutor623]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Primer bulb is supposed to go soft as engine runs; it becomes just a part of the fuel line; you may want to look at rebuild of carbs.

This is true, but the first symptom of a fuel pump issue is that the motor will stay running when the prime bulb is pumped. If I were you I'd add an inline fuel filter to the main hose, change the fuel pump, rebuild the carbs, and change out all of the motor fuel hoses. Sounds like a lot of work but really should only take less than a day (even for the novice). Once you're at that point you should have nothing to worry about for the rest of the season!

 

[stratosguyTN]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

This is true, but the first symptom of a fuel pump issue is that the motor will stay running when the prime bulb is pumped. If I were you I'd add an inline fuel filter to the main hose, change the fuel pump, rebuild the carbs, and change out all of the motor fuel hoses. Sounds like a lot of work but really should only take less than a day (even for the novice). Once you're at that point you should have nothing to worry about for the rest of the season!

The above information would surely do the trick, however it seems like the troubleshooting portion would cease to exist. What should I start out with first? Rebuilding the carbs and buying a new fuel pump is not cheap by any means.

 

[Will Bark]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Fuel pump issue first; either rebuild or get a new one, probably get either right here at iboats. Great price & ship fast.

 

[kenmyfam]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Check the fuel pump output before actually spending money on things you may not need. Pull hose between pump and carb's. Fit temp hose to container, crank motor and watch the output. Make sure you are either in the water or on the hosepipe and muffs to prevent impeller damage. Watch for the following.

Consistent strong spurts of fuel for 20 seconds or so = pump OK
Strong spurts to begin and tapering off as you continue - failing pump
Dribbles or nothing = bad pump.

 

[sutor623]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Check the fuel pump output before actually spending money on things you may not need.

It doesnt sound like this motor has had a decarb since the OP purchased it. That is the only reason why I suggested it. Maybe I am just super paranoid, but unless I have a shop reciept for a recent decarb, when I buy a motor, running or not, I always perform this procedure. Seem too many motors blow due to a little piece of varnish in a carb jet.

And OP, to me the carb kits and fuel pumps are very cheap, in the sense that if you find out the hard way, it can become exponentially expensive.

 

[kenmyfam]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

It doesnt sound like this motor has had a decarb since the OP purchased it. That is the only reason why I suggested it. Maybe I am just super paranoid, but unless I have a shop reciept for a recent decarb, when I buy a motor, running or not, I always perform this procedure. Seem too many motors blow due to a little piece of varnish in a carb jet.

And OP, to me the carb kits and fuel pumps are very cheap, in the sense that if you find out the hard way, it can become exponentially expensive.

Certainly no harm in a decarb although I didn't see it mentioned in your earlier post. Pump output is a quck and easy test and costs nothing. No need to dig any deeper into this till you know you have a working pump.
Just my thoughts on the matter though.

 

[sutor623]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

No need to dig any deeper into this till you know you have a working pump.

Agreed. I change my fuel pump out every so often this day in age regardless of function. One of the upsides of alcohol in our fuel. Just put an ethanol "resistant" one on my 'Rude. We'll see how long she lasts......

 

[Faztbullet]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Agreed. I change my fuel pump out every so often this day in age regardless of function.

This is a VRO/OMS pump at $400+
If it runs fine as long as someone pumps bulb its the VRO or vapor separator problem. A cracked/warped cover on separator will cause fuel pump to loose prime on this system.

 

[sutor623]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

So are they not rebuildable? All the fuel pump kits I have ever had to buy have been $40 or less.

 

[stratosguyTN]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

I appreciate all of your suggestions. I'm about to get on it now and see what I can find. Just FYI - I replaced the the vapor separator gasket about 3 months ago, but I will check the cover for cracks/leaks. I will respond back, once I find out whats wrong.

 

[stratosguyTN]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

So, I pulled the vapor separator and fuel pump off, poured soapy water over them, and primed the system. No leaks. Then, I took the bulb off and ran the main fuel line to another small oil/gas mix tank, bypassing the main fuel tank. Without the primer bulb (in other word, straight fuel line from secondary fuel tank to engine), it started right up and stayed running for over 15 minutes. I revved it slightly and it ran like a champ without hesitation. So, I guess I was over thinking it. Its nothing to do with the fuel pump or vapor separator. Its either the fuel line, primer ball, or fuel pickup in the tank. Woooooooo. (Wiping sweat off of forehead.)

 

[Will Bark]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

The small tank wasn't above the engine was it; in other words you weren't gravity feeding the engine from the small tank?

 

[stratosguyTN]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

The small tank wasn't above the engine was it; in other words you weren't gravity feeding the engine from the small tank?

No sir. The small tank is a 2.5 gallon red "weed eater tank" that I placed in the splashwell of the boat. The motor's fuel line went into the tank in which only had about 1/2 gallon of premix. The fuel level in the tank was about 1 foot below the level of the motor's fuel pump. There wasnt any way that is was gravity fed. Good looking out though.

 

[zippy123]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Was wondering if you finally got your problem fixed?

 

[stratosguyTN]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Huh, well not yet. I replaced the primer ball and it didnt help at all. A buddy of mine had the exact same issue with his motor and he replaced the fuel pump. All worked well then. I guess Im going to have to break out some cash to replace the pump.

 

[stratosguyTN]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Check the fuel pump output before actually spending money on things you may not need. Pull hose between pump and carb's. Fit temp hose to container, crank motor and watch the output. Make sure you are either in the water or on the hosepipe and muffs to prevent impeller damage. Watch for the following.

Consistent strong spurts of fuel for 20 seconds or so = pump OK
Strong spurts to begin and tapering off as you continue - failing pump
Dribbles or nothing = bad pump.

Hey sir,

I performed your test as mentioned and it had maybe 4-5 strong spurts of fuel but then went to a slow dribble, then to nothing. I believe this is a fuel pump issue for sure.

 

[stratosguyTN]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

I finally got around to replacing the fuel pump. Now, it runs great. The only issue is, is that when coming out of the hole, it still wants to bog/die. However, on first launch, it came out of the hole perfectly. I'm still stumped on what's causing this. It seems like its loosing fuel pressure under heavy load. Once on plane, it holds a steady 5500rpm with plenty of power. If it tries to bog/die, choking it helps it get out of the hole. Any suggestions?

 

[Will Bark]

Re: 1995 Johnson Fast Strike Fuel Pressure Problem

Others will chime in but if choking helps wouldn't that point to a high speed jet that needs cleaning out and maybe a carb rebuild? Good luck