1997 Johnson Ficht Loss of Power While on Plane

[Steve from Dallas]

Motor Details:
1997 Johnson Ficht
Model: J150ILEUC
S/N G04283402
Non-Pinned Heads
Champion 7712 Plugs are gapped and indexed (2021)
Fuel Filter (OEM) replaced (2021)
Fuel Bulb (OEM) replaced (2021)
Racor fuel/water separator added (2021)
Replacement ECU has been gone through by MCS (2021)
New ignition module, coils and plug wires (OEM) (2021)

I am hoping someone can provide some sage advice on my next steps, besides replacing the motor. I purchased the motor last year knowing the history of the Ficht motors. The boat (Viper Cobra - One Owner) was too good to pass up. Even if I have to replace the motor in the future I will still be on the right side of the deal.

Compression is 120 - 125 on all cylinders. Fuel is fresh with stabil added. I am running XD-100. The motor has been flawless since last May. About a month ago I started seeing an issue when running on plane. The first time was when I hit a wake at a pretty good speed. The motor decelerated fairly quickly. I was able to pump up the bulb and take off again without issue. A trip or two later at full throttle it started losing power but never shut off. I sat it down and pumped up the bulb and took off again. This has happened several more times since but it doesn't happen every time.

Based upon the manual I have performed the fuel pressure tests (high and low). From all indications the low lift pump and high pressure pump are both performing to spec. The only issue I am seeing is pressure from the service ports on the VST. I even went as far as to remove the valve core on the vertical test port just to make sure the adapter was working correctly to read pressure. Still low or no pressure.

I will attach a diagram with the PSI readings for reference. Based upon the findings the manual suggests that I may have a bad pressure regulator.

This is my theory of what I believe is happening but could be completely wrong:
I believe the lift pump, while on plane, is not producing enough fuel to keep the VST reservoir full because the return line is not returning the excess fuel. The motor will start and idle without issue.

As a side note I do have line of sight to a new OEM VST cover that includes everything I believe to be the issue but didn't want to start throwing parts at it until I got some advice. Any help would be appreciated

Also if anybody has the 1.42b software sitting around gathering dust let me know.

thanks steve

[Bighare2]

What has been done to confirm the fuel tank pickup, anti siphon valve, the fuel hose to the bulb and the primer bulb are not causing restriction? What is the vacuum draw of the lift pump?

[billnorman1]

What has been done to confirm the fuel tank pickup, anti siphon valve, the fuel hose to the bulb and the primer bulb are not causing restriction? What is the vacuum draw of the lift pump?

Does the boat have USCG approved ethanol resistant fuel lines?

[Steve from Dallas]

I have not tested backwards from the bulb to the tank. I guess I need to rule that out before proceeding too much further.

The only tests I have completed on the lift pump was checking the pressure after the fuel filter before the VST, which was at 10 PSI while running at idle and then I did a pressure test of the pulse lines, which both held at 15 PSI for 30 seconds with no loss. I have not tested the vacuum draw of the lift pump. How is this accomplished?

Most of the hoses I would guess are original to the motor (OMC stamped). I did replace the line from the bulb to the steel pick up when I put the new bulb on. Should I go ahead and replace all of the lines as well?

Thanks for all of your help.

[Bighare2]

Suggest testing backwards to be sure and eliminate potential issues.

[DaleH]

The first time was when I hit a wake at a pretty good speed.

Bighare is DEAD ON, rule out the tank, especially the fuel tank pickup on older boats. Happened to me, loss of power @ speed, older OB where people were telling me it was the PowerPack, but one day it would be OK and then not on the next day.

I used two open end wrenches, positioned 180-degrees apart, to remove the pickup off the boss welded to the top of the aluminum tank. Yup .. that was it, the filter screen on the end was LOADED with 'naval' lint. Also check the entire gasline, anti-siphon et al.

Good luck! And make SURE to come back and tell us your success or further diagnosis!

[SEAHORSE]

A quick test of your boat's fuel system is to insert temporarily a length of clear fuel line at the lift pump inlet fitting. In addition install a Tee fitting and a vacuum gauge on the clear hose.

Run the boat at at all speeds and monitor the gauge for any readings approaching 4"Hg. Around 3" Hg or less signifies a healthy system. Look for air bubbles in the line at various speeds. A few tiny ones passing through are normal, but a stream or sausage shaped bubbles are not.

[Steve from Dallas]

Thanks everyone. I will run the suggested checks this weekend. Will advise of the outcome.

[Steve from Dallas]

6/12/2022 Update:

I pulled the anti siphon valve and pickup tube from the tank. I found out the anti siphon valve is only a barbed fitting. No anti siphon from the factory. This would explain how I was able to pump the tank out using the bulb and an extension hose. This was existing before the issue started. The pickup tube looked ok. Still had the carve out on the bottom but no screen installed.

I checked the primer bulb. I was able to squeeze it and then apply my thumb over the end and the bulb would hold vacuum. I also checked the other end with a pressure gauge. Seemed to work as intended but I may not have been checking it correctly.

I hooked up a clear tube from the primer bulb to the lift pump inlet with a vacuum gauge teed into the line. This is where it got interesting. The bulb filled the VST and then proceeded to fill the clear tube until the bulb got hard. A large bubble remained in the line after pumping it up. I started the motor on hose and watched as the clear tube emptied slowly as the motor ran. No more gas ever passed from the primer bulb. As the motor ran I could see the pulses in the fuel line from the lift pump. By the time I shut the motor off there was low spot below the lift pump that had fuel in the line and another low spot before the tee that had gas remaining. The rest of the line from the bulb to lift pump was empty. The gauge showed pressure after priming but drew down to zero and never went below that while the motor was running.

Does this suggest I have a bad lift pump or could the issue still be from the bulb to the tank? It is a 102 degrees in Dallas today so that was all I could get accomplished. By 1pm you couldn't pick up the the tools off the deck anymore. Doesn't help the boat is black and the carpet is dark gray.

I have ordered USCG approved fuel line to replace all of the hoses. Should be here this week.

thanks again for your help
steve

[Bighare2]

As I read by your description there is a lift pump problem. Think of the primer bulb as a hand operated fuel pump. And it is supplementing the lift pump.

[Steve from Dallas]

6/21/2022 Update
I was able to find a complete used unit (lift pump, VST and high pressure pump) on ebay taken from a running motor. It must of been a fresh take off as it was still leaking fuel when I received it.

I R&R'd the entire unit and ran it on the hose over the weekend with no issues. I also replaced the primer bulb and all of the 3/8 fuel line from the tank to the lift pump including all of the smaller fuel lines on the motor.

I was able to get it on the water tonight. It had a great hole shot and actually picked up a little on the top end. I ran it full throttle for several long passes which also included additional hole shots with no issues at all. Then I stopped and fished for about 30-45 mins. Afterwards motor started great, hole shot was good then after getting on plane it fell on its face. I pulled it back to neutral and it kept running but was rough. I reached back and pumped the primer bulb until it smoothed out and the bulb pressured up. I then made several more passes with no issues before it got too dark.

Any ideas? Does this still seem like a lift pump issue? The new used pump is at least rebuildable if needed.

Appreciate any additional ideas
thanks steve

[Steve from Dallas]

Update 6/23/2022
I took the boat out last night and ran it hard. No issues at all. I will consider it a win. Thanks for all of the comments
steve

[mactlman]

Update 6/23/2022
I took the boat out last night and ran it hard. No issues at all. I will consider it a win. Thanks for all of the comments
steve

don't blow it up no parts to fix!!!