advice being sought - mystery problem

[bisonfan]

Somewhat of a newbie here, have been lurking for some time now. I am in need of guidance on the next step for our motor. Bit of history, bought boat off of craigslist (I know, I know) this spring. Boat has a 1990 Johnson 115HP V4. We took boat to local marine mechanic to have prepped for summer use.

Items mechanic looked at/fixed:
compression 125psi all cylinders
new water impeller
replaced bendix (starter-flywheel gear)

We began to use the boat and noticed bogging conditions upon acceleration due to the previous owners lack of use. We have driven several times to get rid of old gas and have run roughly 3 tanks of fresh gas through the fuel delivery system.

This past week we had the same mechanic rebuild/clean the carbs. Mechanic said that bowls of carbs were plastic and warped and were allowing air to enter the fuel delivery system. (We replaced with metal bowls) He also checked the gas tank line and bulb, in good shape (I guess), they passed a pressure test.

We took the boat out today (first time after carb rebuild). The boat now has nice low end torgue. The problem comes in the fact that it seems very senistive to starting, flooding, and non-starting. We had it beached upon shore today and had a really hard time getting it started. We did get it started once we let it sit for about 20-30 minutes (fired right up, assumed flooded). We then pulled a tuber for about 30 minutes, stopped, let it idle in nuetral while we switched tubers and it killed(it idled smooth as can be for 3-5 minutes while we got the tuber setup). Couldn't get it started and had to be towed back to dock, trailered it, went home.

I am thinking something is wrong with the rebuild of the carbs or idle is set to low? Any other ideas or things to have the mechanic/myself look for?

 

[1946Zephyr]

Re: advice being sought - mystery problem

My best advice? Sell it and get a 1957 Evinrude 18hp on a 15' aluminum boat. Problem solved. Easiest motor to start and the most reliable.

Those big V-4's are a lot of trouble and often spoil a good day of fishin'

 

[roncoop75]

Re: advice being sought - mystery problem

We have driven several times to get rid of old gas and have run roughly 3 tanks of fresh gas through the fuel delivery system.

Wait... so you "drove" the boat to get rid of old gas instead of removing the tank, draining it, cleaning it out, putting it back in and then refilling it with new?

Even after 3 tanks through it I'd still dump it if it had bad gas in it. Who knows what kind of junk is floating around in there waiting to screw up the next thing you think you have fixed.

That being said, I'd think a fuel blockage would do just the opposite of flooding it out.

 

[emdsapmgr]

Re: advice being sought - mystery problem

You need two things to run. Fuel and spark. Always possible it is running out of fuel. Maybe a weak fuel pump. When the engine dies, try priming the fuel bulb. Does it get hard quickly, or can you pump fuel back into the carb bowls? If you can pump the primer bulb more than once or twice, you may be refilling empty carb bowls. Also possible you have an ignition problem. Take an inductive timing light with you. When it won't start, check each plugwire for spark with the timing light. Weak ignition components problems tend to occur when the engine gets up to normal operating temps.

 

[mike1245]

Re: advice being sought - mystery problem

im thinking its a carb problem take a few hours and rebuild yourself making sure all ports are clean and floats are set properly i have an 85hp v four and never had a problem out of it ones i cleaned it up and brought it back from dead (sat outside for 5 years ). need help let me know

 

[bisonfan]

Re: advice being sought - mystery problem

Thanks for the adivce guys!

1946Zephyr - we do have a 9.9 evinrude at home on our small fishing boat but it would be a tough push on the 18' bowrider!!

roncoop75 - I never thought of cleaning the gas tank. Unfortunately the tank is built in between the top and hull of the boat I think. There are two accesses to the tank from the floor, both have small coffee can or larger diameter access holes. One is the fuel sending unit I believe, the I am unsure of the other. The tank is metal (is this bad?) What is the approriate method of cleaning once gas is gone? vacumm?

emdsapmgr - Just for kicks, while the boat was idling nicely when getting the tuber hooked up, I squeezed the bulb it was was soft but the became hard at two pumps. It did not have any affect on the motor rpm at all. I am thinking the bowls aren't emptying then and the fuel pump is decent? I didn't get a chance to try pumping the bulb on the last kill as the "new" battery is not very strong (525 amps and 405 CCA) and doesn't crank the motor long (guessing this is an issue??) This brings up another point, I think the starter maybe is bad as it drains the battery after about 10-15 seconds of cranking, it also seems to crank it really slow. This results in having to wait 5+ minutes for the battery to recover before it will spin the motor over. (Sorry I forgot to mention that earlier)

I like the idea of cleaning the fuel tank and am thinking a larger powered battery is a good idea to try before taking the boat back to the marine mechanic?

 

[emdsapmgr]

Re: advice being sought - mystery problem

Your battery is undersized and may have sulfated plates, causing reducing the cranking reserve. Keep in mind that the starter has to spin the engine at a minimum of 250 rpm for the ignition system to fire the plugs. If it spins slower, it won't fire the plugs. A new battery may be a good idea. Two pumps on the primer bulb of a running engine is just fine..

 

[wilde1j]

Re: advice being sought - mystery problem

Describe exactly how you start a) a cold engine and
b) warm engine.

 

[Solittle]

Re: advice being sought - mystery problem

Before you give p on the new battery remove all the cables for at batteryand engine and clean contact surfaces with sandpaper. Apply a light coat of grease and reconnect.

 

[bisonfan]

Re: advice being sought - mystery problem

Thanks for the responses!!

I am starting to believe part of our problem is the battery. The battery was bought by my dad at walmart this spring. Knowing that he "squeeks when he walks" I am sure that it was the cheapest battery available and not neccessarily the "right" battery for the situation.

Hearing the 250 RPM minimum for ignition to fire the plugs, I am guessing the battery is contributing to our hard starting problem.

Wilde1j - upon cold start I have to disengage the throttle as it is a single throttle, I then set the throttle about 1/2 half throttle, roughly one to two cranks and she is off, will run 3-5 seconds before needing a shot of choke. Only two shots of choke were need yesterday, this is the only cold startup after carb rebuild. pre carb rebuild it was the same but about 4-5 shots of choke.

Warm start, pre carb build, were pretty much the same as the cold. Post carb rebuild, I just tried starting it in nuetral but ended having to had to give it a bit of throttle to get it started.

This still leaves me with the question why did it quit while in nuetral with no warning (no coughing, nothing jsut like I turned off the key)

One thing that came to mind while typing this. The marine mechanic told us at the initial work up that the tach side of the recitifer was not working but it was still charging. Now yesterday was different then all other outings, the volt meter gauge read 12-13 instead of 16-18. I wonder if the rectifier finally went?

The boat also was sitting on the water with the battery under cover thus heating up the battery, this may have affected the "cranking power"??? It was 90 plus degrees (hard on batteries?)

Steps I would like to take:
replace battery after checking connections
check rectifier to make sure that it is still charging
have marine mechanic recheck carb settings
??clean gas tank??
???

 

[bisonfan]

Re: advice being sought - mystery problem

bump

 

[emdsapmgr]

Re: advice being sought - mystery problem

The rectifier is responsible to charge the battery and send a signal to the tach for rpm. Sounds like the rectifier is bad, based on your voltage readings-the readings appear to be just that of normal battery voltage. High temperatures are as hard on batteries as very low temps.

 

[bisonfan]

Re: advice being sought - mystery problem

emdsapmgr - I spoke to the mechanic yesterday and explained the situation to him. During the last kill in the middle of the lake on saturday, when I tried to start it, I did not get any horn sound when I turned the key immediately after killing. After sitting for a little bit I did. I also heard a humming sound coming from the starter, didn't click just a hum. The starter is slow spinning as well. I also noticed that the ignition switch was sticking.

The mechanic feels that since there is a quick drain on the battery that the starter is more then likely drawing amps even though it is not spinning. He recommended a rebuild of the starter and replacement of ignition switch.

I did ask him about the rectifier, if that was bad I would have smelled a smoking battery as the recitifer would have allowed the 39 amps to go through to the battery. I don't believe this is the case... I plan to test it but don't have a manual. Where is the recitifier located at so I can test it?

 

[emdsapmgr]

Re: advice being sought - mystery problem

If you heard a humming, it is possible that the starter is spinning-but it is not completely engaging the flywheel. It is possible that the starter solenoid is sticking closed, providing some current to the starter, at least enough to spin it constantly. If the starter continues to spin after the key is returned to the "run" position, it could easily draw down the battery in a short period of time. When the starter is in a continuous to spin cycle, it will generate a lot of heat. You probably not hear the starter spinning when the engine is running. Could also be a bad key switch. Unlikely this is a starter problem-I wouldn't replace it first.

 

[bisonfan]

Re: advice being sought - mystery problem

I ordered a new ignition switch from Iboats.com marine store and am going to install that. I am undecided about the starter. The previous owner let the bendix gear get pretty damaged to the point of the gear hardly engaging the flywheel. The mechanic thought since the gear was beat up pretty good that a bad starter would not be out of the question especially if they had a sticky ignition key.

I definitely think this is an ignition problem (switch, starter, rectifier, battery, etc...). I still want to check for proper charging from the rectifier as the volt gauge should have read 14 or greater on saturday as the battery was pretty drawn down.

Any other ideas on what would draw down the battery in a quick fashion?

 

[Sir Robin]

Re: advice being sought - mystery problem

I had a bad livewell timer that drained my battery. Took a month to find. It would spin the livewell pump ever so slowly so as not to be able to hear it.
I also would like to know where you got metal bowls. My 150 has warped bowls also and my temp fix was to surface them. Werkt for the short term....

 

[bisonfan]

Re: advice being sought - mystery problem

sirrobin - Thanks for the comments. The boat is a bowrider with no fishing equipment installed, so I am thinking motor or radio.... (no bilge or accessories) Hard to believe the radio would be doing it.

As for the metal bowls I am not sure where the mechanic got them. I can find out for yah if you would like me to...send me a PM if you would like to know.

 

[bisonfan]

Re: advice being sought - mystery problem

sirrobin - how quickly did it drain the battery?

 

[bktheking]

Re: advice being sought - mystery problem

The rectifier is responsible to charge the battery and send a signal to the tach for rpm. Sounds like the rectifier is bad, based on your voltage readings-the readings appear to be just that of normal battery voltage. High temperatures are as hard on batteries as very low temps.

Do what emdsapmgr said and test the rectifier. On a small starting battery, which most likely is what you have, it does not take long for starting and stopping and so on to kill battery. Without a working rectifier the battery will receive zero charge and depending on the gear in the boat, lights, radio, fish finder, the charge will be depleated sooner than later.

Even easier would be to put a volt meter on the terminals of the battery (charged and known good) to test, at idle you should see 12.7+ volts, 1/2 throttle up over 13Volts. 12.2 V and lower may indicate a blown diode in the rectifier, this is not uncommon. They voltage with a blown rectifier never changes, it stays static with RPM and never moves.

 

[bisonfan]

Re: advice being sought - mystery problem

bktheking - thanks for the heads up, I will try this over the weekend and see what the resutls are. Will let you know...