1994 Johnson V4 90HP with idle & charging system problems

[churchboyracer]

Just bought a 1994 Glastron ss170 with a Johnson V4 90HP outboard. Compression for all cylinders is around 125PSI.<br /><br />The engine does not want to idle, but it will run if given throttle/revved. All the spark plugs are fouled with oil and fuel. I've noticed that the tachometer works intermittenly. It responds to higher RPM readings, not lower ones. The charging system voltage also seems to work intermittently. The voltmeter gauge sometimes reads a little over 12 volts, and sometimes in the 10-11 volt range. The battery is in good condition and fully charged. The exhaust emits an oily type residue.<br /><br />I tested spark with a automotive spark tester, and it has good spark at all 4 cylinders.<br /><br />Anyone know what this is a sign of? What should I check? I have a Seloc service manual on the way.<br /><br />Thanks!

 

[sycamore]

Re: 1994 Johnson V4 90HP with idle & charging system problems

My V4 88spl had stuck open thermostats and acted the same way. It would not idle and smoked, but when run hard it would clear up and be fine until I idled again. Before replacing the thermostats, I could hold my hand on the engine and not have any discomfort. With the new thermostats the engine runs warmer and idles well.

 

[troska]

Re: 1994 Johnson V4 90HP with idle & charging system problems

RE: Charging/tach issue - Sounds like your rectifier is going. Replace the rectifier and you'll get a consistently working tach, and charge the battery. VM should show 14+ volts when running >2000 rpm.<br /><br />Idle - How old is the gas?<br /><br />Tim<br /><br />

Originally posted by churchboyracer:<br /> Just bought a 1994 Glastron ss170 with a Johnson V4 90HP outboard. Compression for all cylinders is around 125PSI.<br /><br />The engine does not want to idle, but it will run if given throttle/revved. All the spark plugs are fouled with oil and fuel. I've noticed that the tachometer works intermittenly. It responds to higher RPM readings, not lower ones. The charging system voltage also seems to work intermittently. The voltmeter gauge sometimes reads a little over 12 volts, and sometimes in the 10-11 volt range. The battery is in good condition and fully charged. The exhaust emits an oily type residue.<br /><br />I tested spark with a automotive spark tester, and it has good spark at all 4 cylinders.<br /><br />Anyone know what this is a sign of? What should I check? I have a Seloc service manual on the way.<br /><br />Thanks!

 

[churchboyracer]

Re: 1994 Johnson V4 90HP with idle & charging system problems

I charged the battery. It's at 12.6 volts.<br /><br />When I bought the boat, it had very little fuel in it. The owner before supposedly ran the tank empty before storage. I filled it up with about 17gal of premium (92 octane) fuel.<br /><br />I noticed today that the fuel primer (the rubber egg shaped thing) would not get firm when squeezed/pumped. I disconnected the fuel line from the outboard, and used a screw driver to depress the check ball. I pumped the fuel primer a few times and drained the fuel into a clean container. I noticed that there was some debris in it. Afterwards, the fuel primer was able to get firm.<br /><br />Still, it won't idle.<br /><br />Will a bad rectifier affect how the boat idles?<br /><br />I removed the cover for the carbs and noticed a white liquid substance, thin almost like water, but not quite. Didn't really have a fuel smell to it. Could it be that there is water in the tank? Wouldn't 17 gal of fuel displaced it enough for it to burn? Or is this just residue of fuel/oil mixture?<br /><br />I don't see a place for t-stat on the engine. I'm guessing it doesn't have one. I haven't ran the engine long enough to see if it'll idle once hot. I don't want to damage anything in case the engine is running lean.<br /><br />Any other advice is greatly appreciated!<br /><br />Thanks!!!

 

[Basscat 1]

Re: 1994 Johnson V4 90HP with idle & charging system problems

I charged the battery. It's at 12.6 volts.

Thats good you charged the battery, but your boat should be charging with 13 volts or higher with rpms above idle. You will need to check this at the battery with a multimeter.<br />If not, check to make sure all the connections are clean and tight at the battery and the motor. If it still wont charge, then your rectifier is probably bad (it also controls your tach).<br />Concentrate on fixing one problem at time, starting with the charging system.

 

[MarkHPCA]

Re: 1994 Johnson V4 90HP with idle & charging system problems

Yes, work on one problem at a time. A bad charging circuit could easly effect the tachometer. So if you fix the charging then there will probably be two problems solved, one to go....

 

[Solittle]

Re: 1994 Johnson V4 90HP with idle & charging system problems

After you have nailed the charging issue I recommend that you do the following:<br /><br />1. Clean/rebuild the carbs. It is not difficult and will get the water & other crud out.<br /><br />2. Install a water seperator/fuel filter in the fuel line.<br /><br />3. Replace the thermostats & check the overheat alarm. And yes your motor does have them. Check the manual when you get it.<br /><br />4. Get rid of the premium fuel and run 87 octane.<br /><br />5. I assume that you have already or will replace the water pump, spark plugs & change the gear oil.<br /><br />The oily residue you mentioned is normal and is the result of unburned fuel & oil during combustion.

 

[churchboyracer]

Re: 1994 Johnson V4 90HP with idle & charging system problems

I'm guessing it'll be smart to get a carb overhaul gasket kit? Or will it be ok to reuse the old gaskets?<br /><br />I thought outboards are supposed to run premium fuel. What a waste of money! Lesson learned, I paid $40 for those 17 gallons.<br /><br />If I can find the part locally, the rectifier will be replaced tomorrow! Just need to find a suitable puller to get the flywheel off.<br /><br />Thanks for all the help!

 

[MarkHPCA]

Re: 1994 Johnson V4 90HP with idle & charging system problems

Yes use new gaskets. The kit comes with all the required including floats and needle valves. make sure you clean them well with carb cleaner and use compressed air to blow out all the passages.

 

[MarkHPCA]

Re: 1994 Johnson V4 90HP with idle & charging system problems

While you are at it check the various hoses as they can deteriate over time becoming hard and I have seen them start to disintegrate on the inside causeing crud in the fuel system.

 

[churchboyracer]

Re: 1994 Johnson V4 90HP with idle & charging system problems

I went out and purchased a rectifier & 2 carb overhaul kits.<br /><br />Upon installation of the rectifier, I noticed that there was nothing like what I bought (the rectifier) installed on the engine. <br /><br />This rectifier has 3 wires coming out of it: red, yellow, yellow/gray.<br /><br />I can see the voltage regulator unit bolted onto the block, located underneath the flywheel. This unit has 5 wires: yellow, yellow/gray, gray, purple, and red.<br /><br />All the wires go into a junction strip on the side of the block.<br /><br />Seeing that the wires from the rectifier match up to the wires of the regulator, does this mean that the voltage regulator already has a built in rectifier? Meaning, it is a rectifier/regulator assembly?<br /><br />So from what I can see, there is no rectifier installed.<br /><br />I noticed that there is a place for it right next to the junction strip. Does this mean that I should install it and wire it up parallel to the wires coming out of the regulator? <br /><br />Well, I install it anyways. I wire it parallel (according to wire color) onto the junction strip.<br /><br />Boat started, still no idle and no charging system.<br /><br />There are two wires, yellow and yellow/gray that come out from beneath the flywheel. I'm guessing these are the stator wires. Anyone know the Ohm spec? <br /><br />I checked the resistance between these two wires; I think it was about 3ohms. Sound right? Checked each wire to ground to make sure they weren't grounded, it was OK.<br /><br />If anyone has any other advice, it'll be greatly appreciated. I'm still waiting for my Seloc manual, hopefully it'll arrive tomorrow. The manual would probably answer most of my questions. <br /><br />I haven't "monkeyed" with the carbs yet; I'll wait for manual before removing/cleaning the carbs. I would like to get the charging system figured out first. <br /><br />Again, thanks to those that have helped.

 

[troska]

Re: 1994 Johnson V4 90HP with idle & charging system problems

I'm pretty sure your engine has a water cooled regulator/rectifier assembly - you've seen it under the flywheel. There is a spot for mounting the non-regulated rectifier b/c engines that share the same block use that rectifier (mine, for example). <br /><br />Don't continue without the manual - here's an offer. If yours doesn't come in today - I have the same one you ordered (I assume it was the Seloc v4-v8 '92-'01). It's a long weekend, and if you want to work on it, you are welcome to borrow mine. <br /><br />Tim<br /><br />

Originally posted by 94Glastron:<br /> Upon installation of the rectifier, I noticed that there was nothing like what I bought (the rectifier) installed on the engine. <br />

 

[churchboyracer]

Re: 1994 Johnson V4 90HP with idle & charging system problems

Originally posted by Tim Roska:<br /> Don't continue without the manual - here's an offer. If yours doesn't come in today - I have the same one you ordered (I assume it was the Seloc v4-v8 '92-'01). It's a long weekend, and if you want to work on it, you are welcome to borrow mine. <br /><br />Tim<br />

Thanks for the offer Tim! But, my Seloc manual came in today!!!<br /><br />You are correct, my outboard has a regulator/rectifier assembly, paid $90.00 from a local boat part store. What really sucks is that I had already purchased the wrong rectifier. Lost of $40.00.<br /><br />I installed the unit, and now I have a tach signal and a charging system voltage output of 12.8 volts (rather low, I think, but I guess the battery is fully charged and there is no major electrical load on the system). <br /><br />Now to tackle the idle problem. The engine runs rich and it fouls out the plugs immediately. I removed the carbs today and will take them apart tomorrow. Hopefully, this will take care of the idle problem.<br /><br />Anything I should know before removing the carbs? <br /><br />Thanks!

 

[R.Johnson]

Re: 1994 Johnson V4 90HP with idle & charging system problems

If you had water in the fuel tank, adding more fuel will not cure the problem. That water is going to be at the bottom of the tank, and that is where the fuel pick-up is. Pump fuel into a clear glass container, and see what it looks like. Do this by taking the fuel connector off the end of the hose, and pumping the primer bulb.

 

[Basscat 1]

Re: 1994 Johnson V4 90HP with idle & charging system problems

I installed the unit, and now I have a tach signal and a charging system voltage output of 12.8 volts

It will probably climb higher than that once you go out on the lake. Mine usually starts at 12.8, but after I drive it awhile with the rpms up, it climbs to 13.0 or higher.<br />So yours is probably good.<br /><br />Here is a video link you may want to watch before tackling those carbs. Just click the carb rebuilding link on this page. web page

 

[churchboyracer]

Re: 1994 Johnson V4 90HP with idle & charging system problems

I have already checked the boat fuel vs fresh fuel that use in the lawnmower. They both look identical. No traces of water in the fuel, or if there was any, I'm sure it got blended up good. The tank was near empty when I purchased the boat. I don't know how big the fuel tank is, but 17 gallons of premiun brought the fuel gauge up about 3/4 tank.<br /><br />The video link for rebuilding the carbs makes it look so simple. Thanks for that! Looks fun, can't wait to get started!