Boat Performance

Post by **BIG** » November 23rd, 2003, 7:50 pm

Went out of Fort at St. Marks on Sat and the engine wasn't spitting water. After 15 minutes of trying to figure out the problem I was able to unclog the hole and the water pump was spitting water good.

Got in the channel and got on plane to 35 mph and eventually the boat shut down. Attempted it a few minutes later and ran on plane for about 3 minutes and shut down. Boat performed at lower speed <10 mph and I limped to East River. Fished for 3 or 4 hours and headed back and the boat performed perfectly on the way back in.

Went out again on Sunday and attempted to plane and problem arose again. The low oil light came on and I headed to the marina to get oil. Got back in the channel to head south and attempted to plane again, same problem. Eventually limped to marker 35 or so and fished to pass some time. 3 hours later headed back to the fort and the boat performed perfectly.

I have a Stratos 258V, 70HP Johnson and prior to the trips I hadn't cranked the boat since Oct. 13. Saturday I put half a tank of gas in before I went out. I have less than a quarter tank now and the boat worked great at lower speeds.

Questions:
What caused the clog so that the water wouldn't spit out?

Could my problems be caused by old gas or condensation caused by the fluctuations of our tempatures?

Is their something you can purchase to keep the gas 'fresh'?

Should I take it to back to Chris at Bellflower Marine or try to let it work itself out?

What should I do to preserve operating conditions if I don't use the boat often?

Is it just me or has this happened to anyone else? Dampered two great fishing days.

Post by **Sea Fox** » November 23rd, 2003, 8:32 pm

Sounds to me like you picked some trash up in your water pump or maybe the dirt dobbers found them ,they love them. As far as your motor problems, old gas can do what you said or maybe trash or water in your fuel system somewhere. If you dont have a fuel@ water seperator filter you need one even if you use portable tanks. Way to hang in there and go on with day. Good luck!

Post by **Chalk** » November 23rd, 2003, 8:37 pm

Questions:
What caused the clog so that the water wouldn't spit out? Probably a dirt dobber, we put a golf tee in ours as soon as we clean her up, if not they will clog it up

Could my problems be caused by old gas or condensation caused by the fluctuations of our tempatures? Not sure could be, might be a thermostat thing, CSMarine might could answer that?

Is their something you can purchase to keep the gas 'fresh'? Go fishing more

, we unhook our gas line, while flushing the motor out after every trip, run all the gas out of the motor, choke it and crank it til it won't crank, this will keep the fuel from clogging up the fuel system

Should I take it to back to Chris at Bellflower Marine or try to let it work itself out? Couldn't hurt, better safe than broke down

What should I do to preserve operating conditions if I don't use the boat often? Run the gas out of the motor, only trouble motor trouble we seem to have is physical

Post by **CSMarine** » November 24th, 2003, 9:21 am

Hey Big. Don't know squat about motors, just personal experience. It really sounds like a fuel problem, but Johnson and Evenrudes are equipped with thermostats that are nortorious about sticking. They are designed to slow the motor's RPM down if it overheats, to save the motor from burning up. Even if your high temp alarm dosn't sound off, one cylinder my be overheating. If the boat sets a while, they are bad about sticking. The motor will idle great, but will have no power when it comes up on plane, or will shut down. Most of the time it will just act like it's not running on all cylinders.
You should also add a fuel stablizer to your fuel tank if your letting it set for a while. Especially if it's pre-mixed fuel.

Post by **BIG** » November 25th, 2003, 8:21 am

Thanks for the info Chalk and CS!....Went back and looked at the manual and all indications point to a fuel-oil mixture issue....I 'm thinking the combination of low oil and stale gas was the problem. I will check the fuel filter and take it in for its 20 hour inspection.

Another question:
Does anyone think if I would have put 93 octane in instead of the 87 it would have helped the stale gas situation and I could have enjoyed my trips?

dstockwell · Post by **dstockwell** » November 25th, 2003, 8:25 am

Don't think it would have. They say gas starts to break down at the 30 day mark, so a run every two weeks on the hose even if you dont go, and possibly some fule stabilzer the next time you know it will be awhile before you go. I always top off the tank before going again, and have not experienced any problems.

Post by **CSMarine** » November 25th, 2003, 8:28 am

A lot of folks would beg to differ with me but, my 90 Johnson runs hands down better on 92-93 octane. Seen reports on TV that say it don't matter, but my truck would knock like heck if I put 87 in it. Don't see the difference between my boat and my truck motor.

Post by **Tom Keels** » November 25th, 2003, 9:23 am

Older motors will run better on higher octane fuel because most were designed to run on leaded fuel which gives an octane boost. However, newer engines are never supposed to be run on anything but 87. Higher octanes causes them to run cooler and the combustion chamber doesn't get up to temperature because the compression ratio is too low for 93 and you end up wasting fuel. Remember 93 is not a "hotter" fuel. It actually is harder to get to burn than 87 because the additives retard the combustion to prevent preignition. Most folks think a run on 93 every now and then is a good thing, but it isn't.

I would put some stabil fuel stabilizer in it next time if its going to sit a while. After seeing if the pee hole is plugged, it wouldn't be a bad idea to change out the waterpump impeller, just to be safe. A good squirt of carb cleaner in the carbs is probably needed as well because I bet you have some varnish build up if the gas set that long.

Post by **CSMarine** » November 25th, 2003, 9:47 am

Tom, what are you calling "older motors?" Mine is an 1987 Johnson. Shields used to put nothing but "white gas" in all their guide boats. that was in the mid 1960's. I do know my new 17hp Murray Lawnmower will not run right on high octane fuel. It needs 87.

Post by **Tom Keels** » November 25th, 2003, 9:57 am

70s-80s. Most of the marine manufacturers didn't start re-designing engines until the late 80's. He didn't say how old his motor was, but I was just giving out some info for all the folks who may have thought that burning 93 in their engine might help it run better.

dowawoo · Post by **dowawoo** » November 25th, 2003, 6:15 pm

I rebuilt my 90 hp evenrude last winter...broke a ring, it is a 96 model...after the rebuild had the same thing happen to me that happened to you...problem was that there is a small plate the thermostats go into and there is a bleed hole there, what happened to me was trash got in to it and blocked the flow, causing sort of a air pocket. and there it created a block..a friend who is a outboard mechanic said, put it in reverse and give it some gas let it back flush it some, did that and it was fine..have had it happen since and I just repeat it..
I also have a oil injection system, have had the float in the oil tank stick giving a false reading and causeing the alarm to go off...shook the tank and all was well...
If I can be of any help let me know.
don

Post by **BIG** » November 25th, 2003, 11:11 pm

Interesting.....my motor is a '96 too. Hopefully I can get out sometime next week and try this low budget solution. This dialogue has definitely been informative.

I'll keep ya'll posted.

Post by **tin can** » November 26th, 2003, 8:12 am

I would suggest you eliminate the oil injection. On 1999 and older non- fuel injected OMC outboards, the oil injection system is not reliable. If you mix your fuel in the tank you KNOW there's oil in the gas.

If you determine it is a carb problem you'll have to tear the carbs down to eliminate the varnish and goop buildup. The high speed jets are in passages in the bottom of the bowls, and the only way to eliminate the problem is to go into the carbs and clean them.

The thermostats are infamous for sticking on these motors. The 96 motors were designed to run hot to more efficiently burn fuel. You can eliminate the thermostats, but the motor won't run correctly. New thermostats are about $15 each.

The last thing that comes to mind is the ignition system. If it does it again, check the firing of each cylinder by pulling 1 plug wire at the time. If you pull a plug wire and there's no change in the way the motor is idling, you might have an ignition problem. It might be time for a new power pack. I'm thinking this might be your problem because no alarms sounded. If it were an oil or overheat problem one of the alarms would have sounded. OMC power packs are also infamous for partial or intermittent failure.

dowawoo · Post by **dowawoo** » December 2nd, 2003, 11:44 am

you know I changed the thermostats in my motor, same as the newer ones, and the temp runs the same as my brother in laws 99 johnson. as for the oil injection, if it works its good, I too have been told to watch it, but it does work, I check it, and know it works...I hate mixing oil and gas...no exact mix, for me, again, for me , oil injection does what it is supposed too.. I rebuilt my powerpack, reason, ring , the piston has a small pin that spaces the rings apart it receded and allowed the ring to catch and broke, not uncommon....face it, when you run a motor 4500 plus rpm nothing is forever...
I like to keep things as they are manufactured....but if I had a problem with my oil injection I would take it off or bypass it...no big deal. Never had a problem with the carbs, went through them, was a waste of time , nothing wrong, I use prem. gas, evenrude carbon guard and I check the plugs and compression...hey, no tow truck out there.
need more information ask

Post by **Rogan** » December 2nd, 2003, 5:49 pm

Dont know if your model even has poppet valves in the cooling system but my yamaha does and basically the same thing your talking about happen to me. Problem was a poppet valve was sticking and would not allow enough water flow through the cooling system to properly cool the engine. Engine would run fine at lower RPM's but as RMP's increased the engine would shut down. In my case water by passes the T-stat once RPM's reach a giving point and water is redirected through the poppet valves allowing much more water movement through the engine. I was told this happens a lot of times when engines sit and salt water dries around the valves and eventaully create valves to stick. I would not be surprised if freshwater from hoses with a high mineral count (lime) may not do the same thing. Again, I'm no outboard mechanic but its worth asking about. And its not a big deal to fix or it wasnt on the yam.