Problems with my 2003 175 Johson (again)

[EDEERNET]

My motor is doing the same thing it was last season. When I put it in gear, most of the time the engine dies unless I hammer it. When I try to put it on the trailer it dies everytime I put a load on the prop (embarrassing at the ramp) I took it into the dealer last summer (under warranty) and they said my fuel mixture was too lean, so they adjusted it. It does the same thing now, could it have something to do with the air temprature? Is there something I can adjust myself?
Also, I just bought some Bomb engine tuner (Could this solve my problem?) It says on the can to let it sit for 3-16 hours, Would it hurt if it was longer (24-30 hours) After I do this, how long should I wait before changing my plugs?


Modified by EDEERNET at 3:36 PM 5/16/2005

[RUSTY63]

Check the cylinder head temp, it should be around 140-160 degrees, the thermostats get stuck open and the motor will spit and die, the thermos are at the top of the head behind the round plastic cover.

You will need a 13/16 wrench or socket to remove the cover...(spark plug socket) pull the spring and thermo out, you may find shavings from the internal block holding them open.

Also, remove the air box and be sure the throttle plates are closed.

[EDEERNET]

Thanks, Rusty
What is your opinion on the decarb?

[RUSTY63]

If you are running XD-50 you should decarb once a year.....I don't think it will help with your problem.

[EDEERNET]

I have had it since August 03 and haven't done it yet. I have been running XD-50. Does the amount of time that the tuner sits in the engine matter? I am going to pick up new plugs after work. You have said in the past that decarbing will ruin the plugs. How long should I leave them in after I decarb?

[RUSTY63]

Yes, the amount of time the tuner stays in the motor is important, follow the directions on the can, the longer the better but, not any longer than what is suggested on the can of Bomb Engine Tuner.

[EDEERNET]

I pulled the covers of the thermostat and took them out, I didn't see any crud that would cause them to stick. Do I need to check the throttle plates while it is running or shut-off. I pulled my plugs and they looked pretty black and oily. I got new ones,but How long after I do the decarb should I wait to change the plugs?

[RUSTY63]

Check the throttle plates with the motor off.

After the decarb, take the boat for a ride...About 30 minutes at around 3500 RPM's, when you get back in, change the plugs.

[Javelin389]

My 01' 175 does the same thing when I go to load it up at the end of the day. Especially in the warmer temp like we are having now. Occasionally it will do it while on the water. It's been like that ever since it was new. Rusty, what kind of a backlog do you have right now? How long would it take for you to look at it?

[EDEERNET]

I took mine in last summer and had it serviced. They adjusted the fuel mixture (it was too lean) But it went back to normal by the end of the season. You are right though the problem only happens after the engine is warmed up.

[SEAHORSE]

Also make sure the linkage is adjusted so the spark advance starts moving at the same time the cam is starting to open the carbs. A lot of motors are set wrong from the factory and start opening the carbs too soon, causing a bogging or lean condition.

As the boy said, thermostats are super important, too!

[RUSTY63]

It will be next week, give me a call at the shop, phone numbers in my siggy.

[EDEERNET]

I give up I checked the throttle plates they are all closed. Did the decarb changed my primer bulb on the fuel line, changed my plugs. Do you guys have any more suggestions before I take in to my mechanic. Would the fuel mixture be temperature sensitive? How do I adjust the mixture?

[THE WITCHDOCTOR]

First off... Will it not idle at all in gear>
And like seahorse said... sync and link might be off, causing the timing and throttles opening to not jive. Also if the base timing is off, can do this as well.

[EDEERNET]

I can get it to idle in gear, but when I go to accelerate it bogs down and dies. And this only happens after it warms up

[Chadc77]

I have a '04 Johnson 150 that does the same thing, when the motor is warm. I can go to a fishing hole and fish for 30 minutes and crank up and leave and the motor will die when i give it gas. I have noticed this problem for the last 8 months. I wish I could find a simple fix before the long trip back to the dealer.

[STILLSMOKEN]

Edeernet, Javelin,

I have a 98 johnny 150 as well and it does the same exact thing. Replaced the anti syphon in tank, new bomb bulb, all new hose clamps, cleaned filter etc. didn't help at all. I will check advance tonight. Thought I did that last year and it looked ok.

[SKINTBACK]

Got a 2000 model 175 that has been doing the same thing. I ended up adjusting my hot foot to make it idle higher for a temporary fix. If you happen to figure it out please post here. This seems to be a very common problem.

[RUSTY63]

As Seahorse posted, the Sync and link on this motor is very important.

Standing behind the motor, look at the right side top, about center but at the top, you will see a arm that extends under the round cover, it has a roller on the end, that roller must touch the other arm in front of it, if its not touching loosen the screw in the arm and move the roller until it does touch.

There are a few other things that can cause this, the vapor separator chamber float stuck or adjusted wrong, a bad vapor pump, on motors 5 years old or older warped float bowls on the carbs or the brass plug leaking in the side of the bowl.

I have seen once.......the fuel inlet tube cracked as it came into the motor cover, it would suck air but would not leak fuel.

[EDEERNET]

Thanks, Rusty I will have to check that out. Sounds like alot of people have been living with this problem. I did notice when I had the cover off that I could push the throttle open quite a bit with out that arm moving. Is it supposed to do that. Hopefully it is out of adjustment and I have not gotten full throttle out of her I could use a few more MPH on my topend