Motor Trouble--Any Ideas?

[Catch 22]

Stats:
1998 Johnson Sea Runner
90hp, 2 stroke, oil injected.

Symptoms:
Large amount of oil coming out of the exauest ports, not were the cooling water comes out. Starts fine, seems to run fine but I have not reved it up at all. I am looking for advise on what this means, how bad it is, and most importantly a trusted machanic to take care of it for me (Seattle/Everett area)

I have a video of it running so you can see what I am talking about, if I figure out how to get it on here I will post it.

[Larry H]

I would give the oil the 'smell test'. If it smells heavily of gasoline, you may have one cylinder that is not firing. Its not easy to tell on a two cycle engine at idle if it is not firing on all cylinders.

The next step is to remove the spark plugs and inspect them. A good plug is brown on the center electrode and dry/blackish on the shell. If the entire plug is wet with fuel/oil it may not be firing.

Another possibility is that the VRO unit is over oiling. If all plugs are equally oily that is possible. If the flow of gasoline is interrupted, but the two cycle oil flow to the engine is maintained, the VRO pump will continue to pump oil, causing the engine to over-oil. The flow of gasoline can be interrupted by air in the fuel line. If this is suspected, inspect all connections in the fuel system. All connections must be tight, no cracks in the hoses, and check the o-ring in the fuel connector at the engine. It can crack and leak air.

Never disconnect the fuel line on a VRO motor to attempt to 'run dry' the carbs. This will definitely cause the VRO pump to continue pumping oil into the carbs and make restarting very difficult. Over oiling should be noticeable by the very heavy smoke from the exhaust on startup.

Never rev up a two cycle outboard while it is running on a flusher. The engine needs the back pressure of the exhaust being in the water, in the normal operating position. A two-cycle engine can easily overspeed if reved up in the air.

Larry H
Retired outboard mechanic.

[Catch 22]

Thanks Larry-- I did check all the plugs/wires last year and they seemed fine. Over oiling seems like a real possibility here. I am hoping to get the boat out and ready for summer next weekend. I will certainly look into this. I do believe I had a fuel leak right at the motor last year shortly before this started. A good place to start for sure, I will keep you updated, and look for further advice when I get going. I love working on boats but hate working on motors so we will see how much this tests my patience...

[Larry H]

Kevin,

If fuel leaked out, air will definitely leak back into the fuel line when the fuel pump sucks fuel into the motor. That air leaking into the fuel line will cause over oiling.

I would really check all fuel lines, replacing any that look old or are hard or loose on the fittings, and be sure to use clamps that fit, not oversize clamps. The plastic 'Snapper' clamps are preferred. Also check the fuel line inside the motor cover going from the inlet fitting to the VRO pump. If you decide to replace any fuel line attached to the VRO pump, cut the old hose off the plastic fittings on the VRO pump. Use a razor knife. Do not pull or twist those hoses off the VRO pump. You can easily damage the pump. Very $$$ !

[jennykatz]

If the problem persists you can take out the VRO pump. and just pre mix 50/1
We had a90 Johnson that had a oiling problem and we just took out VRO and ran it at 50/1 and no problems after that .

[Catch 22]

OK...

I found a vacuum line that had been pinched shut, now it is open an unrestricted. I do not seem to see the large amount of oil coming out the exaust that I saw before but it is still very smokey (I guess I dont know how much smoke there should be)

There is also a red valve with a cap/air fitting like on a tire I suppose, that I feel may be contributing. I think it is a valve on the primer solenoid? The motor runs when it is in the down possition and quicky stalls out if I turn it to the up possition. Could this valve be causing over oiling? It seems to slide back and forth with some slop, and I thought I saw a bit of fuel pour out of it when I turned it to the up position. What is the red valve for? Where should it in terms of up and down? How hard should it be to move? what is the air fitting on the end of it for? ANY IDEAS?

[Adeline]

[Adeline]

Here's some good info

Re: explain the primer system and the primer lever please?

The primer solenoid is a valve that allows fuel to bypass the carburetor so that it can be injected directly into the intake. The purpose of this is to enrich the fuel so that the engine can be started when cold.

The initial charge of fuel is supplied by squeezing the primer bulb; after that, you should have additional pressure from the fuel pump as you crank the engine.

The handle on the primer soenoid is there for emergency use when and if your battery dies and you have to rope start the engine. At all other time, the handle should be aligned with the cylindrical base of the solenoid.

Again, the primer solenoid is for cold starts and should be activated by pushing the key in while cranking when required.

Please see the thumbnail for the normal operating position of the lever.

While the primer bulb is providing pressure and lifting fuel to the primer solenoid, it is also filling the float bowls at the bottom of each carburetor.

Once the float bowls have fuel in them, the vacuum created by the movement of the pistons pulls fuel through the carburetor.

The fuel leaving the float bowls is pulled through to the firing chambers, not pushed.

[Larry H]

The red valve is a manual enrichment valve (primer) for rope starting (can anyone actually pull start a 90hp?). The valve is normally closed. If you open the valve when the engine is running, it will flood the motor, like a manual choke would.

There is an o-ring on the red lever inside the black housing. Most likely, the o-ring has split and is leaking gas out and air in. The repair is not difficult, but it is a trick and unless you know the trick, it might be best to let an experienced mechanic do it.

The repair consists of buying the red lever part, which comes with a new o-ring and And then replacing the lever inside the black housing. That black housing is the start enrichment (primer) solenoid. When you push the key in when starting, the solenoid open the valve and lets more fuel flow to the carbs thru the small hoses while starting. The small black hoses are not vacuum hoses, they supply the extra fuel to the carbs for starting

That solenoid only works while the engine is cranking. Pushing the key in when not cranking does nothing but make a clicking sound.

Most likely, the small diameter black hoses should be replaced at the same time the valve is replaced. That would also be a good time to replace any other under hood hoses that are hard or cracked. The alcohol in the fuel is hard on the hoses, especially on a motor of your motor's age.

At the same time, go over the entire fuel system from tank to motor, to ensure the hoses are in good shape and tight on the fittings. Any hose that turns on the fitting is loose and can leak air into the fuel system, causing over-oiling.

If you remove any hose from a plastic fitting under the hood, cut the hose off the fitting, (an Exacto knife is good),do not pull the hose off the fitting, it can damage the fitting, especially on the VRO fuel pump or the solenoid valve.

Sounds like I am writing a shop manual, which is a good thing to have if you try to work on your own motor. Get the factory shop manual, not a Clymer type manual.

[Catch 22]

Wow, thanks for all the advice/input. It sounds like you are on the right track. I did find that most of the vacuum lines (small diameter hoses) were loose, for today, I cut the ends off and put them back on with zip ties. I also took some rubber tape we use when vacuum forming parts in the shop, and wrapped i around all fuel connections and that red valve. The motor seemed to smoke a lot less. It did seem to run really rough, more so when I revved up the engine. So, I do believe I need to replace all vacuum hoses and fuel lines. under the hood, and will. I will hire someone to replace the red valve/ O ring.

Question: I think I recall hearing that the lower unit needs to be under water or under load to run right when revved up, is that correct? I had the water intake under water but not the vents higher up on the lower end. Could this be why it is running rough while testing?

Question: Some water is coming out of the exhaust ports, is this normal?

Question: Does anyone recommend a trustworthy mechanic?

[Larry H]

Running a 2-stroke motor on a flusher or in a bucket is just to flush or verify starting.

DO NOT REV UP a 2-stroke motor on a flusher or in a bucket!!!

Without the normal back pressure of being in the water, the motor can exceed 10,000 rpm and explode!

Shops test a 2-stroke on a dynomometer which applies a load to the motor. The only other way to run at wide open throttle is on the boat out on the water. Even if the boat is in the water, do not rev up the motor in neutral! Same badness as above.

You cannot verify how a motor will run under load on the land unless its being run on a dyno.

Best thing is to actually test run the boat.

There is an exception and that is whats called a 'test wheel'. That is a funny looking propeller kind of thing (Note highly technical jargon LOL) that loads the motor. A test wheel can be used by backing the boat down a launch ramp till the motor is normally submerged and running the motor in gear.

Since most of us don't have any access to a test wheel, don't try to run your motor up to high speed on land or in neutral! Only bad things can happen!

[Larry H]

[Catch 22]

Thanks to all who helped me figure out what was wrong with my motor. I am very happy to report that I finally took it out for a shake down on Lake WA yesterday and it performed perfectly. Started instantly, with no hesistation and very little smoke and ran great. I cruised the whole lake and logged around 40 miles testing both tanks to include every fuel connection. After making sure all vacuum lines/ fuel lines were tight it made a world of difference. It was the perfect start to summer for me, moorage at Shilshole starts on June first...

On a side note:
We witnessed a bald eagle kill a seagull, drag it on top of the water for about two hundred yards (as it was too big off payload to get much lift) and drop it on someones dock. Then it plucked every feather off the bird and ate it. We watched the whole thing from maybe 40 feet away. I had no Idea bald eagles would go after a seagull... Very interesting to see.

[starcrafttom]

Glad to hear We need to get together and fish some this summer.

I saw two eagles just off the highway in Arlington today with a kill of some sort. They were eating and a coyote was sitting a ways off watching them eat. Dont now what they were eating or who killed it. Eagles will eat almost anything they can catch, steal , or find.

[Catch 22]

Yeah Tom, i plan on fishing as much as I can again this summer. Let's be in touch for sure...