IF I DID THE COMPRESSION TEST CORRECTLY THIS IS WHAT I HAVE.........

[77TEXAN77]

I have a 1992 Johnson 200 HP V6 Model # J200STLENS Serial No # G 03021021

IF I DID THE COMPRESSION TEST CORRECTLY THIS IS WHAT I HAVE:

60 lbs. psi in 3 cylinders. 65 1/2 PSI in the other three Cylinders. That doesn't sound good to me.

I have no problem getting out of the hole.

I can travel about 42 mph to 50 mph between approx. 5400 RPM to 5800 RPM'S.

However, I hardly ever push it to 50 mph. And very seldom run her over 5500 to 5600 RPM'S.

It's seems to me she isn't going as fast at 5600 RPM'S so that's what made me do the compression test yesterday. What do ya'll think?

Sounds to me like a rebuild?

Also, I do mix her a little rich when mixing the oil & fuel. In doing so will that cause the spark plugs to be wet? They were pretty wet when I pulled them out.?? Thanks :)

[gearcaseman]

Your compression sounds pretty low, but at least they're close to being equal. I would try another gauge just to be sure, and then I would consider doing a bore check with some inside micrometers to see where you were on oversize holes. The rule of thumb is @ .004-.006 over the standard bore size, and then you need to think about boring or sleeving. Another thing to look at is if this engine has the compression relief holes toward the top of each cylinder. If it does, an old trick is to swap sleeves from one side to the other as this will close off these reliefs and give a boost to compression.

[77TEXAN77]

Yea, that's about what I was thinking. Probably begin planning a rebuild. :(

Although, in doing the swapping the sleeve trick how much does it increase the compression .. roughly? And what are the downsides to swapping those sleeves and side effects on other parts of the motor?

[ChampioNman]

may want to try a decarb with BRP engine tuner before doing a rebuild. And as Eddie says try another gauge. The STLENS isn't a very high compression motor.

[Bassmeister]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by ChampioNman &raquo;</td></tr><tr><td class="quote">may want to try a decarb with BRP engine tuner before doing a rebuild. And as Eddie says try another gauge. The STLENS isn't a very high compression motor. </td></tr></table>
+1

[77TEXAN77]

When ya'll say the STLENS isn't a very high compression motor ..... do any of ya'll know what the compression specs for this motor would or should be at a minimum to maximum status?

[ChampioNman]

Depending on the gauge you use 80-90 PSI. But after close to 20 years of service it is probably time for a refresh.

[77TEXAN77]

The gauge I have is made by "OEM" and reads up to 300 psi. So how does that factor in to this situation? Also, forgive my ignorance but how does one do this "decarb" project that has been mentioned above?


Modified by 77TEXAN77 at 7:01 PM 6/14/2010

[ChampioNman]

All of them vary, to decarb buy a can of BRP tuner and follow the directions on the can. If you have never done this to the motor I would suggest you start with applying Seafoam to the fuel and running it to loosen the carbon then using the engine tuner as it is an extensive carbon remover. If you have a water separator then remove it and fill it with Seafoam and reinstall it run your motor for a day and then decarb with BRP engine tuner.

[77TEXAN77]

Oddly enough I just put some Sea Foam in it a few days ago when I filled the tank. So I guess I'll do this recarb effort within the next few days.....

I do not know if I have a water separator or not. If so about where would it be on the boat/motor?


Modified by 77TEXAN77 at 1:33 AM 6/15/2010

[ChampioNman]

Follow your fuel hose from the tank through the battery compartment. Look for a spin on filter like an oil filter that is the water separtator.

[77TEXAN77]

I don't have anything like that from the tank to the motor. I've replaced the fuel sending unit and a section of the fuel line in the past and had my hands everywhere there could or should have one between point A (The Tank) and point B (The Motor) and don't know how I could've missed that so it must not exist on my boat. The only filter I have is an small in line fuel filter inside the motor housing.

So guess maybe I should add one?

[ChampioNman]

Wouldn't hurt. If you have a portable 6 gallon tank you could mix up a shock batch of Seafoam and run it in the motor.

[77TEXAN77]

Interesting Idea I may do that. Is there a down side for example braking up carbon etc where is it gonna go? Could this effort break it free and send it somewhere in the fuel system say the Carbs and cause other issues or does this treatment actually dissolve the carbon?

[ChampioNman]

An outboard motor is nothing more than an air pump. Whatever you put in the intake it will go out the exhaust. If you can't push it out you can't make it.

[overdrivecb]

decarb it on your driveway and youll get to see where it comes out and what it looks like for a long long time
ps ....if you like your grass or driveway find somewhere else to do it

[77TEXAN77]

Still haven't got to it yet but perhaps this weekend. How long would I have to run it with the water hose attached while doing this recarb. I've seen some people run it out of that water "WITH WATER HOSE CONNECTED" for quite awhile but I've never liked doing that. I've always been afraid it was asking for trouble. Maybe if this process entails running it that much I should find a barrel somewhere and fill it and use that???

[ChampioNman]

You aren't running it at High RPM's just fast idle and as Overdrive said don't do it on a concrete drive way it will stain it. It will smoke out the hood too. Let it sit overnight and fire it back up. Take it to the lake if you like and blow out the bad juju there.

[PJCodner]

Also never run the motor without water going to it. Run it in the lake or on the muffs. It doesn't take long to heat up without water. You run it without water you will eventually get to see the insides of a non working outboard.

[77TEXAN77]

Yes, I never ran it "ever" without water running through it.

When I use the muffs in the drive way I only do that to give it a quick pre start before driving all the way to the lake to discover it won't start. I drove to the lake once right after I purchased the boat let her drift of the trailer to discover she wouldn't start. :( Had to get wet on a cold day to get back on the trailer.

So the point is I use the muffs at home pre start in drive way before leaving especially for looooong trips. But I only let it run even with the water hose connected for just a few seconds.

Then once she's backed in at the lake I start the engine before disconnecting the winch strap.

I've figured if she didn't start in the drive way at least I didn't waste a trip to the lake and I would rather work on it if need be at my house as opposed to having to do so on the water.

But a question I have is how long can you safely run it using the muffs and water hose without damaging the engine?