1996 Johnson running bad - I need help!!

1996 200 Johnson

I need some help to get my Johnson running right again.
Last weekend, the engine started fine and idled good for 10 minutes to get out of the boat cove. I then accelerated normally and drove for about 15 minutes at moderate speed.

The problems began after I had stopped the boat for a few minutes. The engine would start and idle fine, but when I put it in gear and try to accelerate, it died over and over again. I tried hitting the choke button, but it did not help.

When I finally made it back to the ramp, I checked the plugs and one plug was pretty oily, but the others looked good with light tan insulators. While on the water, the water pressure was good and the pee hole showed good water flow.

Now for my confession.....I do not have stabil in the tank and I had not run the motor for about 9 months. Does it sound like the carbs are gunked up? If you think that may be the problem, is there a fix short of taking them all off and going through all of the carbs??

Your help is appreciated!! http://www.bassboatcentral.com/smileys/bows.gif

Jay

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jay’s snake &raquo;</TD></TR><TR><TD CLASS="quote">Now for my confession.....I do not have stabil in the tank and I had not run the motor for about 9 months.</TD></TR></TABLE>

First, I would suggest you check the compression, if it is within 15 pounds on each cylinder then I would look at the ignition system.

If all looks good I would drain the complete fuel system and rebuild the carbs.

Ok...that is sound generic advice, but does anyone have anything more specific.

For instance, What should I look at if I take the carbs apart? Where does the old gas cause problems? Does this even sound like a fuel issue?

Why was that one spark plug oily? It was the top plug on the right side. What number plug is that? I read a post about jetting one carb differently. Is that the cylinder that was mentioned?

Should I try an additive or carb cleaner first? I saw someone mention Seafoam. Does that sound worthwhile?

thanks!!!!

Jay


Modified by jay's snake at 9:25 PM 10/11/2008

Put some seafoam in the gas.

Check to see if your primer bulb is still firm when it won't run..If you pump the bulb will it take off then..? Could be that fricken heat soak..
As far as the oily plug that cylinder could be running richer than the rest of the engine for a multitude of reasons....Could be as simple as being jetted richer..If you are talking about the top plug on the right side I believe that is the number 2 plug and pretty much everyone is running that cylinder a bump or 2 richer..
Do a search under heat soak, or Vindicator, venom etc and you will find a ton of info...

Jay,
I had the same problem.
1. Replace all the spark plugs first.
2. Make sure the thermostats are functioning correctly.

Shade tree method. Start engine on muffs. Watch that no water exits vents on each side, above lower unit when you first start up engine. When engine reaches operational temp. water should start to flow out these vents. If water flows from the start, one or both stats may be stuck open. Also touch each bank and see if they feel the same temp.
The thermostats are located on the upper part of each bank. It's important that both banks are operating at the right temp or you will experience trouble.

Check these things first before moving on, you may be surprised.

Good luck.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jay’s snake &raquo;</TD></TR><TR><TD CLASS="quote">Ok...that is sound generic advice, but does anyone have anything more specific.</TD></TR></TABLE>

Jay, Take this guy's advice................he is one of the best in the business with J/E outboards. http://www.bassboatcentral.com/smileys/wink.gif .........................Roger http://www.bassboatcentral.com/boardstuff2/beers.gif

Hey Roger,

I apologize if my response sounded negative, but I wasn't trying to insult anyone.

A compression test sounds like a good way to hopefully eliminate major engine concerns and I plan to do a compression test as soon as I can and I'll post the results.

Thanks!!!

Jay

No apology needed Sir................stick up your model and serial # so these guys can help you......................some of the best J/E tech's in the world watch these boards...................be patient and help will come.........................RR http://www.bassboatcentral.com/boardstuff2/beers.gif

Mister Hornet, Seems ya bucking fer my Jr. Mod status!! http://www.bassboatcentral.com/smileys/wink.gif http://www.bassboatcentral.com/smileys/Laugh.gif

Nope, I could never fill your shoes Mike...........................Roger http://www.bassboatcentral.com/boardstuff2/beers.gif

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bassmeister &raquo;</TD></TR><TR><TD CLASS="quote">Mister Hornet, Seems ya bucking fer my Jr. Mod status!! http://www.bassboatcentral.com/smileys/wink.gif http://www.bassboatcentral.com/smileys/Laugh.gif </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by The Green Hornet &raquo;</TD></TR><TR><TD CLASS="quote">Nope, I could never fill your shoes Mike...........................Roger http://www.bassboatcentral.com/boardstuff2/beers.gif </TD></TR></TABLE>

There maybe a full time opening http://www.bassboatcentral.com/smileys/wink.gif http://www.bassboatcentral.com/smileys/Laugh.gif

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ChampioNman &raquo;</TD></TR><TR><TD CLASS="quote">

There maybe a full time opening http://www.bassboatcentral.com/smileys/wink.gif http://www.bassboatcentral.com/smileys/Laugh.gif </TD></TR></TABLE>

http://www.bassboatcentral.com/smileys/eek.gif http://www.bassboatcentral.com/smileys/roll.gif http://www.bassboatcentral.com/smileys/roll.gif http://www.bassboatcentral.com/smileys/roll.gif

Well I did a compression test and it does not look good.

Here's how I did the test....I ran the engine for a few minutes to warm it up. I then wired the throttle open and disconnected all plug wires. I then pulled one plug at a time and installed the gauge and cranked it over.

All cylinders were at 50 lbs. except the top one of the left side. That cylinder would not register anything on my gauge. It did have some compression when I put my thumb over the plug hole, but I guess not as much as the others.

First of all, isn't 50 kinda low?? I was expecting more like about 100.

Any idea of the most likely problem with that cylinder? The plug looked normal so it seems like it was firing OK. What should I do next, short of pulling the engine apart?

thanks!

Jay

Hmmmm, while I'm waiting for some input...... I'm really puzzled by the low compression numbers. I actually used two different gauges and I got the same numbers. Both gauges are kinda old though.

I'm not sure it should even run with compression like that and it ran pretty well at higher speed until I stopped.

Obviously, there is a problem with that one cylinder. Should I try squirting oil in the cylinder before performing another compression test? Does using a de-carbon chemical make sense?

On a happier note....How about those Longhorms!!! http://www.bassboatcentral.com/smileys/smile.gif

Sounds like a bad case of ring stick. Pull the heads and inspect the cylinder walls I bet you will see some major scuffing. Sounds like the motor has never been decarbed.

Here is the latest update.

After cleaning the carbs, I decided to put in clean gas to see if it would run any better. I took it out and it ran pretty good and it did not have the dying problem any longer. I didn't have a speedo connected, but it seemed to have good power and didn't seem like an engine with such lousy compression.

I then took the plug wire off the zero compression cylinder and tried it again. The engine missed a little but still ran pretty good leading me to believe that that cylinder is not contributing it's normal amount of power.

I'm thinking about decarboning the cylinders to see if that helps compression. What is the recommended procedure and what product works best?

Thanks!

BRP engine tuner shot through the carbs with the motor running on muff at idle and up to temp. Follow the directions on the can. When the motor cuts off. remove the spark plugs and shoot a some tuner into each cylinder while turning the flywheel by hand to make sure you have good coverage. Let it sit overnight and restart it in the morning. You will kill any mosquito within 10 miles from all of the smoke and don't do it on a concrete driveway as it will stain from all of the junk coming out!!

Thanks Championman!

Now if I can just find a driveway to do it in.........maybe my neighbor when he's gone? http://www.bassboatcentral.com/smileys/Laugh.gif

Or ya can do it the night before you go to the lake. Get up the next morning go to the lake and run her good for at least 15 minutes. If something happens that you can't make it to the lake then back her into the yard and run it on the muffs. Just don't let it sit in there longer than overnite.