Bad Gas, Maybe??

[nelsongg]

Hello all
I have a '00 2150 5.0l Alpha I gen II. First time in the water this season. Dropped her in. Started just fine. Began idling out of the NWZ when I hit the mud bottom with the outdrive and it stalled. Raised the leg a little. Started back up and got back to a little deeper water and continued out of the NWZ without additional incident or appearant problem. Started to throttle up and seemed slightly rough. As I continued the RPMs just came up slightly/slowly. By the time I got to full throttle, the RPMs were at 2000 and gradually got to a max of 2600. Max speed was 26/27 mph, barely on plane. I brought it back to neutral and pushed in the button to throttle up without it going into gear. No problem with the engine, it revved right up. BTW, all gauges normal. I limp back to the ramp and pull it out of the water. Upon visual inspection nothing looks out of the ordinary. I have since mostly emptied the fuel tank and replaced with new gas and changed the fuel/water separator filter. No Change. I removed the prop yesterday cleaned out all the old grease, put in new grease and reinstalled. Prior to doing this the prop spun freely.
Is my next check going to be checking the carb for water?

Thanks,

 

[Silvertip]

Re: Bad Gas, Maybe??

First, reving the engine in neutral proves nothing as an unloaded engine will rev to the limit with half the cylinders dead. Many people think and engine is running ok when it actually is has one or more dead cylinders. You are shotgunning the problem which is not a good diagnostic technique. When was this engine tuned up last? Do the cheap and easy stuff that can make an engine run well or run poorly. Check the plugs. They can tell you in an instant whether the engine is running rich, running lean, or whether the cylinder is not firing at all. Make sure you have spark on all cylinders. Check fuel pump pressure. If you don't know how to do these things the next step should be to invest in a service manual for your specific engine and drive.

 

[jerryjerry05]

Re: Bad Gas, Maybe??

Start it on the trailer.Put it in gear and see how the prop looks.If you had no problem the year before and if you have a water seperating fuel filter check it.Jerry

 

[nelsongg]

Re: Bad Gas, Maybe??

First, reving the engine in neutral proves nothing as an unloaded engine will rev to the limit with half the cylinders dead. Many people think and engine is running ok when it actually is has one or more dead cylinders. You are shotgunning the problem which is not a good diagnostic technique. When was this engine tuned up last? Do the cheap and easy stuff that can make an engine run well or run poorly. Check the plugs. They can tell you in an instant whether the engine is running rich, running lean, or whether the cylinder is not firing at all. Make sure you have spark on all cylinders. Check fuel pump pressure. If you don't know how to do these things the next step should be to invest in a service manual for your specific engine and drive.

I pulled all the plugs prior to going out for the first time and they looked fine. The plug wires, rotor cap and rotor were new the beginning of last season. I did not, but will check for spark at each wire tonight. I have a service manual and have been looking thru it for some semblance of my problem, but I haven't found anything yet that mimics my problem.

 

[nelsongg]

Re: Bad Gas, Maybe??

Start it on the trailer.Put it in gear and see how the prop looks.If you had no problem the year before and if you have a water seperating fuel filter check it.Jerry

I have already done this and the prop looks fine. The fuel filter has been changed once already since this started. Are there any other filters in the fuel flow to the carb that could be clogged?

 

[gamarines2]

Re: Bad Gas, Maybe??

could it be that his prop hub is spun and the limp-home mode is good enough to get him on plane but certainly not optimal?

 

[JustJason]

Re: Bad Gas, Maybe??

Are there any other filters in the fuel flow to the carb that could be clogged?

Yep there sure is. You changed the one on the boat side right? it was a spin on cartridge.
Depending on your setup you have 1 or 2 more. You should have one in the carb right behind where the fuel line goes in. And depending on the fuel pump it may have 1 in there to. If you can post your serial ## and we can look it up.

 

[JustJason]

Re: Bad Gas, Maybe??

could it be that his prop hub is spun and the limp-home mode is good enough to get him on plane but certainly not optimal?

Nope, if he had a bad prop or hub he would get full rpms but no speed

 

[nelsongg]

Re: Bad Gas, Maybe??

Nope, if he had a bad prop or hub he would get full rpms but no speed

Thanks Jason. That's the answer to the question I was going to ask next about the RPM's.

 

[nelsongg]

Re: Bad Gas, Maybe??

Yep there sure is. You changed the one on the boat side right? it was a spin on cartridge.
Depending on your setup you have 1 or 2 more. You should have one in the carb right behind where the fuel line goes in. And depending on the fuel pump it may have 1 in there to. If you can post your serial ## and we can look it up.

I don't have the s/n with me right now but I will try to get it when I go home for lunch.

 

[nelsongg]

Re: Bad Gas, Maybe??

I don't have the s/n with me right now but I will try to get it when I go home for lunch.

Got the engine s/n, but part was rubbed off of the tag on top of the spark arrester. Is it stamped on the block somewhere?
This is what I could read: OL_63_89

 

[nelsongg]

Re: Bad Gas, Maybe??

Well, I checked everything in the fuel system and took it out this weekend and still have my problem.
While I was out with the engine cover off, I noticed a popping noise that sounded almost electrical. It was not rythmic, but random as if something was loose (couldn't find anything loose) and tapping against the engine while the boat bounced. I also only heard it while the throttle was fully open.

Then this morning I came across this blurb on the sterndrives.com website: "Did you know that a bad plug could cause arcing on a Thunderbolt coil? We have customers who replace arcing coils when the only real problem
was a bad plug or plug wire."

Has anyone ever heard of this or had it happen to them?

I'm heading out after I post this to pick up a compression tester and an inline ignition spark tester.

Thanks, any and all guesses will be appreciated.

 

[bruceb58]

Re: Bad Gas, Maybe??

A bad or plug wire can easily cause arcing across the coil. The energy form the coil has to go somewhere. If the wire or plug is bad, the energy released from the coil will try to go the path of least resistance. This is very hard on the coil.

You should run your engine at night sometime with all the lights off. Amazing what you will see if you have bad plug wires or plugs.

 

[Fishermark]

Re: Bad Gas, Maybe??

I pulled all the plugs prior to going out for the first time and they looked fine.

Did you try new plugs? What plugs are you using? I know several have experienced problems with Champions and AC Delco seem to be the plugs of choice for most.

The plug wires, rotor cap and rotor were new the beginning of last season.

Is it possible you pulled or twisted too hard on a wire when you took out the plugs? Easy to do. Just something to check - I would check each wire and replace again if uncertain as to its condition.

 

[nelsongg]

Re: Bad Gas, Maybe??

A bad or plug wire can easily cause arcing across the coil. The energy form the coil has to go somewhere. If the wire or plug is bad, the energy released from the coil will try to go the path of least resistance. This is very hard on the coil.

You should run your engine at night sometime with all the lights off. Amazing what you will see if you have bad plug wires or plugs.

Would the noise I was hearing (described above) be the arcing coil? Or would an arcing coil be more rythmic, arcing every time it discharged to the bad wire or plug?

 

[bruceb58]

Re: Bad Gas, Maybe??

Would the noise I was hearing (described above) be the arcing coil? Or would an arcing coil be more rythmic, arcing every time it discharged to the bad wire or plug?

It could be rythmic if the plug or wire is bad enough. Like I said before, run your engine in the dark. I had some older spark plug wires once. It looked like a lightning storm going on. During the day, you had no idea how bad it was.

 

[JustJason]

Re: Bad Gas, Maybe??

get a cheapie test light light this one

http://www.sears.com/shc/s/p_10153_12605_00999290000P

ground it out and start dragging the tip of the probe along the wires... if your wires are leaking the bulb will light up (and you won't light up)

 

[nelsongg]

Re: Bad Gas, Maybe??

It could be rythmic if the plug or wire is bad enough. Like I said before, run your engine in the dark. I had some older spark plug wires once. It looked like a lightning storm going on. During the day, you had no idea how bad it was.

Well, I waited until after dark last night to see if I had a lightning storm in my engine compartment and nothing. But I also didn't hear the popping noise, even when I throttled it up. I might need to put it back into the water to put a load on it and try it again.

 

[nelsongg]

Re: Bad Gas, Maybe??

get a cheapie test light light this one

http://www.sears.com/shc/s/p_10153_12605_00999290000P

ground it out and start dragging the tip of the probe along the wires... if your wires are leaking the bulb will light up (and you won't light up)

I have an inline spark tester that I put on each spark plug last night. All plugs lit the bulb in the tester to the same brightness and blinked how I would expect them to. Obviously this won't tell me if voltage is bleeding from the cable along the way. Can I use a multimeter in lieu of the tester above to check for bleed off?

I also did a compression check last night with the following results:
4 @ 180
3 @ 175
1 @ 165

Should I be worried about the one @ 165? Anyone have any other ideas at to my power problem? I'm beginning to get very frustrated.

 

[chiefalen]

Re: Bad Gas, Maybe??

i know i might get jumped on for this but im just trying to help this guy so here goes.he hit a sand bar everything in the motor is good.the outdrive binding somehow.out of alignment?just throwing it out there better minds here than me.some sand or something got sucked in and messing him up?