2005 Johnson 175HP Need Help and Advise

[cvitech2]

I have a 05 Johnson 175HP. I have had a few problems over the years and they appear to be getting worse.

1. The no oil alarm goes off at idle (in no wakes) and occasionally on a long run. I verified many times that it is using oil by marking the reservoir. If I let it go, it goes out after about 10-15 seconds.

2. The motor runs poor at idle after running a while. May be due to hot weather, but it?s hard to make long runs in no wakes. It will spit and sputter all the way.

3. The motor will lose prime on hot days or after long idles, this problem is getting worse.

The motor is reliable, always starts and gets me there, just needs some TLC to do it. I did routine maintenance the last few years including de-carb, plugs and compression checks. I always run 2+4 and Carbon guard. I bore scoped the pistons last year and they were spotless, I had scoped them in 2010, they were dirty...which led me to use the carbon guard. I found a small air leak on the dip tube in the tank in 2011 and replaced it and checked all the lines. I removed the aftermarket fuel filter that I thought might be restricting it. I took it to a local dealer and was very upset that the boat sat for 5 weeks with no service. I got the boat back a week ago and am trying to cipher myself.

Is it possible to switch the motor to EFI?

I am so frustrated I am thinking of just trading it in on a new motor.

Any help or thoughts would be appreciated.

 

[JJB]

Re: 2005 Johnson 175HP Need Help and Advise

On #2 question maybe your low idle Jets are clogged . Does it run good on wot ? if so , may just need a good carb cleaning or time to do a rebuild on them . On Question #3 it may just be a bad primer bulb check valve losing it's prime , depending how it is sitting keep the arrow facing up can help a bad/weak check valve get you home through those no wake areas without popping all the way . As far as the EFI , i'm a carb kind of guy so could not help you there !

 

[cvitech2]

Re: 2005 Johnson 175HP Need Help and Advise

It seams to just have intermitent problems across the board. I wsa thinking it could be the fuel pump? I am on my 3rd primer bulb. I have mounted them vertical and horizontal. What is the fuel pressure I should have? I can check it on the crank side I guess. Does the fuel pump use the air from the vacuum on the cylinders? I was thinking that if the VOR pump was bad or going bad this could maybe cause all the problems. I find it strange that the problem could last this long though. I think the carbs are pretty clean. I have never rebuild them, but visualy inspect them and it appears the 2+4 and seafoam seem to keep them clean. For the check vavle in the diptube, primer bulb and fuel pump to be bad seems suspecious. I cant figure out how the fuel would leak out after sitting for awhile, unless I have poor suction on the pump?

 

[JJB]

Re: 2005 Johnson 175HP Need Help and Advise

Does the motor run good at wot ? if so the motor is not starved for fuel at wot and the fuel pump is working ? Popping at idle is a tell tail of a lean condition at idle . It can only come from lack of gas or bad spark . If you push in your choke button when the popping happens and it stops it's running lean from a carb problem( choking bypasses carbs right into manifold ) .. I have had carb problems after motor ran well all day but would pop as soon as I idle down . A carb can look clean but you need to open them up to check the jets or dirt in the bowl or dry up oil build up in the jets . you can also put a toothpick in the intermediate air-bleed orifice screw of each carb one at a time to see which one is running lean and it can be more then one so have a few of them . when you place the toothpick gently in air bleed screw for that carb it will make the carb a rich mixture and stop the pop if it's that carb or slow down the rpm if it's not . it's a easy way to locate which carb is clogged . When you pump you primer ball up how long will the prime hold ? can you start the boat say 1hr later without pumping the ball up ?Sometimes if the carbs don't hold prime the needles could be sticking ! Sounds you have check out the fuel system that includes the fuel tank pick up screen in fuel tank ? Vro systems need to be check for any air leaks in the system . also check around the vro mixing chamber and filter for leaks . once you know it not the fuel system or vro, I would check out the power packs or stator low circuit .If you can put a induction timming light on each plug wire to see if you have bad ,coil , plug wire or spark plug the light will mis fire if bad .. Does it have a fast start circuit which is connected to your heat sensors to advance timing on start then kick it down after warm up .. or course this all go without saying that the boat was running well and was timed and syn , before these problems started . I had both a bad stator and a clogged carb with factory metal shaving in the jet that was a interupting problem . I run pre mix the vro fuel pump was $$$ to replace and was a pain of the butt keep from getting alarms from air leaks in rough seas for me so I gave up and premixed . I been running pre mix for 10 yrs and boat runs 30 mi off shore 8 hrs trolling a day and never one problem in 10 yrs. I do rebuild my carbs every 4 yrs and water pump every 2 yrs . Fuel pump pressure 4 psi @1000 rpm , 5 psi @5000 rpm .fuel tank must not be below 30" of fuel pump .. The Johnson is a workhorse always starts and easy to fix , keep it ! It also only weights 375 lbs try to find that in another 175 . The only thing with the plastic carbs on the 175 is to take care with plastic bowls screws not to strip them by over tighten them . always use new gaskets when resealing . There easy motors to work on and most of the problems imo are the vro air leaks or fuel leaks that make the vro system fail and cause motors to run lean and lock up . It's a little hard hearing those no oil alarms running 3000 rpm off shore with a radio on. usually by the time you hear the alarm it to late unless its a new e-tec . Never Let you 2 stroke sit more then 4 weeks unless you spray it ,those 2 stroke rings get sticky quick ! and yes the fuel pump uses a pulse vac from crank case , connect you fuel gauge on the load side of fuel pump not pulse line . seafoam is a great product ! never crank you motor without spark plug wires connected or grounded with proper spark plug tool checker .. Hope it helps JJB

 

[Faztbullet]

Re: 2005 Johnson 175HP Need Help and Advise

It seams to just have intermitent problems across the board. I wsa thinking it could be the fuel pump?

With the oil alarm your on the correct track. Your engine has adjustable low speed jets and they have a special way to be adjusted, the toothpick test is for the low speed jet not the intermediate. The loosing prime and popping is due to fuel pump not keeping up with demand from internal problem or a air leak. The vapor separator on front of engine if top is warped or loose will cause VRO/OMS pump to loose it prime due to air leak.

 

[cvitech2]

Re: 2005 Johnson 175HP Need Help and Advise

That?s a lot of info JJB, I think I might have a seizure trying to understand it all. So were should I start? I am mechanically inclined so I just need some direction. The motor runs good at WOT. It will throw the no oil alarm occasionally there. 95% problems are at idle under load, like i am no waking. I don?t feel much or hear much at idle in neutral,

I thought they quit using plastic bowls in the early 2000's?

Should I check for the leaks on the vapor separator first?

 

[JJB]

Re: 2005 Johnson 175HP Need Help and Advise

Hey op ,Sorry for the overload , but was trying to give a few things to check out in this process ? I had the same problem when I first got my motor 10yrs ago with intermitent problems coming from more then one problem that can be hard to trouble shoot . just start with step 1 fuel system , if it check out move to step 2 electrical ignition system . DO you have a factory manual ? I agree with fuztbullet , as far as the vro/oms system vapor separator .the system must be totally sealed without leaks . On my 2000 175 it also has a float and needle valve inside of the vapor chamber that works like a carb float valve to keep the fuel at the right level in the mixing vapor chamber .. it's made of plastic and can warp and cause leaks and fuel delivery problems if not working proper .. I replace my vapor separator unit complete , because it was warped and the old needle and float valves was sticking also . you need to check every hose clamp connected to vro/oms fuel system . I made a small air hose rig to put 3- 5 lb of air pressure on my fuel system .connect it to the input line of the gas filter and then closed off the output side of the hose leading to the carbs . I found leaks in my vapor separator and fuel filter cover and one hose clamp by spraying soap/water around the gasket and hose clamps and look for air bubbles leaks .Caution !!! Just make sure there no gas or oil in the lines first before you pressure them ! this would be your starting point ! Go over the entire fuel and oil system for leaks if not done already . Hang in there , your in the same boat as many vro/oms owners with a lot of great people on this site that will help you with it . JJB

 

[cvitech2]

Re: 2005 Johnson 175HP Need Help and Advise

I am going to check the vapor seperator and fuel lines tonight. Is there any instructions on removing the seperator. I do not have a booklet for the motor. I would purchase one online if I knew were to look. I googled some pics of it, just wanting to maybe have a little more direction if I pull it. I will let you guys know what I find.

 

[cvitech2]

Re: 2005 Johnson 175HP Need Help and Advise

Okay, I ran into a small problem. When I recieved my service manual and starting reading about checking the vapor seperator, I am under the impression that there is not one on a carburated motor, just fuel injected. Is this correct?

 

[Faztbullet]

Re: 2005 Johnson 175HP Need Help and Advise

On my 2000 175 it also has a float and needle valve inside of the vapor chamber that works like a carb float valve to keep the fuel at the right level in the mixing vapor chamber .

Thats not correct as the float and needle have nothing to do with fuel ,when needle and float open it allows VAPOR to be drawn out by vapor pump on top of VS unit.

I am under the impression that there is not one on a carburated motor, just fuel injected. Is this correct?

You have one,,,VRO/OMS pump is mounted to it and its in between the port/starboard carbs