Crap.... Engine woes (long, but help me please)

[Acer2428]

So I took the predicor out for the first time today on quite possibly the busiest, longest, most akward ramp in the Midwest (Saylorville lake for those in IA).

Put it in the water and couldn't for the life of me get it to start. It would turn over and not catch. Pumped the primer bulb, put it in neutral, 3/4 throttle and still took me a couple of minutes. Then as soon as I would throttle back toward neutral it would cut out.

Finally got it to go and putzed around and waited for my buddy to park the truck. Once we got out of the no wake zone, she flew.....sort of.

I would be at 1/2 to 3/4 throttle and it would be chugging kinda hard, not breathing right, then out of nowhere... BWAAAAAA *put put* BWAAAAA and take off like a bat out of hell.

We parked it and went swimming for a bit, it fired right up. However, on the way back she would NOT go over 3,500 rpms or so. It would chug and as soon as I tried to give it more throttle, it would die out on me (tried slow and fast).

So after a while of playing with the trim, scratching my head, I trimmed it all the way up and tried once more.....and she just took off.

But, she's watertight and runs....kind of. People were starting to get pissed at the ramp. Feels almost like it's loading up on fuel. Int he no wake zone I was having to keep around 3,000 rpms just to keep going..... Didn't seem right to me for such a light boat.

Fuel: I bought generic 2-cycle oil at the local auto parts place that said it was for manie applications. The bottle said 2.6oz's per gal of gas for a 50:1 which is what I wanted (so said the PO). I tried to drain all the old fuel out, but I know there was some left. I put in almost 9 gals of gas (how big is the tank?) and put in 24oz's of oil. Also, right before I launched, I dumped in 14-1/2 can of seafoam.

The fuel gauge must not work. PO said it did It showed 1/8 tank even after I had filled it up.

HOORAY FOR USED BOATS! Any help you guys can afford me? I think it sounds like a may have to pull/re-build the carbs? I'm going to try to hook up the muffs and and do the carb-on-motor seafoam decarb.

 

[83PREDICTOR]

I cait help much with the engine but your tank is a 16 gallon

 

[Acer2428]

I cait help much with the engine but your tank is a 16 gallon

That's really odd. I used a hand pump to pump out as much gas as I could until the gauge read empty and I had a hard time finding a solid stream of gasoline. Then it only took 9 gals today at the pump. Doesn't LOOK like it's big enough to be a 16gal, but I'll take your word for it.

PO thought there might be some bad gas in it, hence why I tried to pump it out. Could bad gas make the motor act THAT funky? I suppose it could contribute?

 

[Combat Rock]

im thinking you have a carburation problem
maybe a jet is plugged

has the boat been sitting long?

 

[Acer2428]

Probably a month or two, yeah.

PO said it had a stutter at partial throttle. But this was WAY worse than he described.

 

[daren34]

some of the problems could be the cheap oil
i had a v-4 140 that would leave you on the other side of the lake on cheap oil

might be better to pull the carbs and clean them good
look in the intake and make sure the reeds all look good while you have the carbs off

good luck daren


nothing like being the life of the ramp


we all have our turn

daren

 

[Chris E]

NEVER EVER USE CHEAP OIL!

Merc, omc, yamaha, or a high quaility synthetic!

check the compression and electrical, start with the simple stuff and move forward from there - did you check the primer bulb for fuel flow?

 

[Blizz]

If it's been sitting 2 months your carbs are screwed take em off and clean clean. While i don't recommend the cheapest oil you can find your old merc won't be bothered by the use of off brand oils as the worst oils of today are better than most of the oils available 25 years ago when your motor was new. Again i'm not saying use cheap oils just it doesn't seem to bother most of the older mercs.

 

[sawcat]

That's really odd. I used a hand pump to pump out as much gas as I could until the gauge read empty and I had a hard time finding a solid stream of gasoline. Then it only took 9 gals today at the pump. Doesn't LOOK like it's big enough to be a 16gal, but I'll take your word for it.

PO thought there might be some bad gas in it, hence why I tried to pump it out. Could bad gas make the motor act THAT funky? I suppose it could contribute?

length x width x depth in inches divided x 231 = gallons

Good Luck

 

[Acer2428]

I was wondering what the formula was, thanks.

As far as the cheap oil, it was the only thing around here. Unless I want to go 20 miles out of my way, there's no marine store between here and there. It was the only stuff O'rileys had.

check the compression and electrical, start with the simple stuff and move forward from there - did you check the primer bulb for fuel flow?

Comp. I checked when I bought it. How does one check the electrical? Also, the primer bulb remained hard and it seemed as though it was getting too much fuel (more likely not enough air). than running lean.

When you say 'clean the carbs' do you mean rebuild them? Obviously if I soaked them in gas, the gaskets would need to be replaced. Is there somewhere I can buy a gasket set (pat # would be great).

I'd hate to pump out 10 gals of gas..... And yet another $30 lost to the boat...lol

 

[Chris]

I would start with a compression test and go from there.

I don't know how many times members screw around with their motors chasing problems without doing the obvious first thing, which is checking compression.

Crappy gas can definitely cause some problems.

I can't even start my lawn tractor will gas that has sat over the winter (5 months) without stablizer.

When you're working on it, you can always try hooking the motor up to a separate tank which has fresh gas in it and see what happens. If the gas is punky, you'll most likely need to clean up your carbs.

The other obvious thing to check is that you've got good spark at all plugs. And if you've got a bad switch box or stator, sometimes they'll run great cold and act up when they're hot or vice versa. But regardless, check and make sure you've got good spark.

 

[Blizz]

Yes i meant rebuild them. More times than not nowadays if your motor sits for a while it's carbs because todays gas is crap and then when you mix oil with it it's even worse. I would not leave gas in your boat for more than a couple of weeks unless you've put stabilizer in it. Don't soak your carbs in gas to clean them as it will not get the crap out of your jets and circuits go back to your local O'reilly's and get some real carb cleaner.

 

[LilSki]

When you crank it does it just crank over with no signs of life and then suddenly it comes roaring to life? Or does it fart and sputter and quit until you get it going?

I ask this because if it is fuel related it will usually show some sign of life when cranking. It will usually catch a cylinder every now and then until you get enough fuel in there. If it just cranks and cranks with no popping or farting and then all of a sudden starts running, then I would go towards the stator or something ignition related. mainly because that is what mine was doing and I chased fuel delivery problems for a week. Then I changed out the stator and it fixed everything.

Remember the stator has two sections. it has a high speed and low speed. If only the low speed is shot it will be very hard to start and idle or won't start at all, but if you get it going will run fine. It can be the other way around and start right up but drop a cylinder as you speed up and then come back and run fine. Or it can do both and be hard starting and drop cylinder ot two on the top end.

But you may want to check the carbs first as it will definatly be the cheapest thing to check. Just pull them apart and make sure everything is clean and that the float levels are ok and that the fuel seats seal up ok. But if cleaning the carbs does nothing then I would definatly go after the ignition system.

 

[Acer2428]

When you crank it does it just crank over with no signs of life and then suddenly it comes roaring to life? Or does it fart and sputter and quit until you get it going?

I ask this because if it is fuel related it will usually show some sign of life when cranking. It will usually catch a cylinder every now and then until you get enough fuel in there. If it just cranks and cranks with no popping or farting and then all of a sudden starts running, then I would go towards the stator or something ignition related. mainly because that is what mine was doing and I chased fuel delivery problems for a week. Then I changed out the stator and it fixed everything.

Remember the stator has two sections. it has a high speed and low speed. If only the low speed is shot it will be very hard to start and idle or won't start at all, but if you get it going will run fine. It can be the other way around and start right up but drop a cylinder as you speed up and then come back and run fine. Or it can do both and be hard starting and drop cylinder ot two on the top end.

But you may want to check the carbs first as it will definatly be the cheapest thing to check. Just pull them apart and make sure everything is clean and that the float levels are ok and that the fuel seats seal up ok. But if cleaning the carbs does nothing then I would definatly go after the ignition system.

No popping or back firing. At first it wouldn't catch at all. After 4-5 tries, it would feel like it was going to start. Finally it did start, but wouldn't stay running in anything other than 1/2 throttle +. I tried keeping it at 1/2 throttle for 20 seconds or so to see if I could then throtle down, but it still pooped out on me. I'll do another compression test today.

I really appreciate all the help, as this is my first OB and only my second boat (decieving, as I owned the first one for about 3 weeks before I bought this one...lol)

 

[Acer2428]

Just thought of something that may indicate a carb problem (and my stupidity).

Waiting to go onto the ramp, I was showing my buddy how to start the boat and I went ahead and primed the bulb until it was hard.

I went to put the motor back up to take it down to the ramp. As I trimmed up, gas poured out of fron/bottom of the case and into the splash well..... And this was a decent amount of gas, not a few drips.

Is this normal, or would it indicate I have a carb problem?

Thanks again

 

[bdusted440]

It is a good indication of a stuck float as when the bowl is full the float should close the needle and seat and stop the fuel from coming in the bowl.or you could have a cracked fuel line.Which will cause similer problems.2c From my experiance with outboards.:cheers

 

[Big Dave]

Also if it is the inline6 115, check the diaphragm fuel pump on the side of the engine
to check the spark, you can get a board to hook all 6 plugs too at once and watch for yellow spark(read weak) or no spark...
check dist cap and rotor for corrosion and carbon tracings(looks like kids drawing in pencil on inside of cap)
when you pull the plugs, are they black, black oily, or black powdery?
should be burning tan to light brown on the white inside portion of the plug
we got to the point we would not buy any oil but johnson gt or yamalube

 

[Acer2428]

Went and bought my own comp. tester today. I was going to do it, but read that poor functioning/coke'd up carbs could throw off the readings. If so, should I sea foam the crap out of it first and then try a comp. test, or just do it?

I live in a townhouse, so hooking up the muffs takes some doing.

As far as spark, I have a timing light, so I can just hook that up and see what I get.

And, as carbs go, I figure it certainly won't hurt anything to give them a good rebuild. I just need to know if there's a kit out there to make my life a little easier?

Will take pictures and pull plugs as well. Thanks for all the help guys.

 

[Old Hickory]

Acer,

check your fuel line and connections first; make sure your fuel tank is vented properly as well. I always start w/ the simple things then work my way up to the more complex. good luck.

Rod

 

[Boston Predictor]

Remove all the plugs, hook up the compression guage and have a friend turn it over for about 6 seconds or so while you check the readings on each hole. I dont think clogged carbs would effect it.

Im pretty sure your boat has to be under load inorder to check the timing.

Good advice so far by the others.

Compression #1
Spark #2
Fuel #3

You dont neceseseraly need to rebuild the carbs, just clean the bowls and jets very good and go from there.
It sounds like a carb or coil problem to me.
keep us posted