More mysterious behavior -

[CRT Skiff Crafter]

Howdy folks. <br /><br />Well, yesterday I drug the boat down to the Ohio River for a change of pace. <br /><br />Everything was great until shortly after I gassed up. The engine started missing and surging and dying. The symptoms I have experienced of late - dying as soon as being put in gear after a restart, returned. It would start and idle perfectly fine. However, under load it was a no go. <br /><br />I checked the float level, which was a little <br />low. After a bit of tweaking it ran for a few minutes and then returned to the above mentioned pattern of bad behavior. Interestingly, when I got it running for a couple of minutes, using the trim tabs made the engine act up as though the fuel supply was being cut off.<br /><br />It sure seems like a fuel supply/carb problem, but I don't know what to try next. The carb has been rebuilt and the fuel pump passed all standard tests. Two things that may be coincidental, but seem to be consistent, the problem starts when I gas up at a marina and after a good solid hour or so of operation. Also, this problem of dying and then can't put it in gear after a restart, materialized for the first time after the marine mechanic replaced my gimbal bearing, although that could be coincidence as that was the first time I gave it a good run after all the engine work I did.<br /><br />Something I did notice for the first time yesterday was that I saw a small amount of some light colored smoke around the stern drive when the engine started running rough, although I can't verify that this is really a new situation or that I just never really noticed before. <br /><br />I probably should mention that I installed a Mallory breakerless distributor recently. Is it possible that this has something to do with the resistance loom wire getting hot and breaking down? <br /><br />I'm really getting frustrated with this as I have done a ton of work on it, new distributor, coil, plugs and wires, rebuilt carb and timing gears and chain, all of which were needed and dramatically improved performance. I am not opposed to putting it in the hands of my mechanic, but my fear is that it won't act up and I'll throw money at it with no benefit. I mean when this behavior isn't occurring, the engine runs like a dream! <br /><br />Needless to say I'm <br /><br />Anyone have a thought on this?<br /><br />Regards, crt.

 

[flashback]

Re: More mysterious behavior -

CRT, you said this problem occured shortly after gassing up. could you have gotten some bad fuel? posibbly having water in it. just a thought.......good luck........

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

Hi flashback. Thanks for the input. <br /><br />Well, bad fuel is a possibility, but the last time this happened I checked and changed the water/fuel filter and the fuel looked fine. <br /><br />It seems to show up after the engine has ran for a while, although well after the engine is good and warm. <br /><br />I just don't know?<br /><br />Regards, crt.

 

[rattana]

Re: More mysterious behavior -

You seem to have taken care of most of the mechanical and fuel problems. Since you are saying that when you use the trim tabs the motor stumbles, it appears to be electrical. I would monitor the voltage on the positive side of the coil when running. If the voltage on the positive side of the coil drops too much when using other electrical devices, it will cause the motor to run poorly and even stall out. When monitoring the coil voltage put your positive lead on the + side of the coil and the negative lead on the engine block. The voltage is reduced due to the resistance wire. I think it should be about 9 volts +\- 1 volt. When starting it should be 12volts. You may have other issues with the shift interrupt switch if it stalls going into gear. You could bypass the shift interrupt switch to eliminate that.

 

[merc 140 pontoon]

Re: More mysterious behavior -

Rattana - I believe the spec is 6 to 9 VDC with the resistance cable or ballast resistor in place. The problem is that electronic modules which are incorrectly wired to the coil positive post can shut down below 7 to 8 VDC.<br /><br />CRT-<br /><br />The symptoms of missing and dying match what I had.<br /><br />

I installed a Mallory breakerless distributor recently. Is it possible that this has something to do with the resistance loom wire getting hot and breaking down?

I had that problem recently, but my symptoms were not identical to your's. My resistance cable in the harness was deteriorated, and increased resistance as it heated up. This would take about 30 to 45 minutes. The related probem was that the mechanic installed my Pertronix Ignitor wrong--he had the positive feed for the Pertronix coming from the coil positive post, which is wrong if you have an externally-resisted coil. It's supposed to go to a 12V switchable source. When I measured the voltage at the post, at times it got as low as 7.5V, and the Ignitor was shutting down. Pertronix told me this is a very common problem. I wired the feed correctly, and it helped, but I still had coil problems. I tried a 1.8 ohm ballast resistor on the transom (bypassed the resistance cable) without much luck. At the suggestion of a mechanic, I bypassed the resistance cable, got rid of the ballast resistor, and switched to an internally-resisted coil. In theory, that should hurt my starting, because now all 3 ohms (1.8 ohms resistor plus 1.2 ohms normally in an externally-resisted coil) is inside the coil, and hence after the crank-assist wire coming from the starter (which is meant to deliver 12V to the post as a starting boost). Still, with that set-up my ignition problems are gone. I have good spark, it starts well, and my Ignitor doesn't shut down. It turns out that by going to this coil, I always have 12V at the coil positive post, so in the end I wouldn't have had to move the Ignitor feed, but it's done, and I'm happy with it.<br /><br />

It would start and idle perfectly fine. However, under load it was a no go.

This is the main difference. My module would stay off until the engine compartment cooled enough to drop the resistance in the deteriorated resistance cable (in the harness). I found that the extra blower I added helped, but it was a band-aid, not a fix. I don't see why a load would affect the voltage at the coil, unless there's an issue with your alternator.<br /><br />Good luck. Please post what you find.<br /><br />Steve

 

[rattana]

Re: More mysterious behavior -

Thanks Merc, I wasn't sure about the voltage. Measuring the voltage at the coil will at least let you rule out that part of the equation. Good luck CRT and let us know what you find out.

 

[loadnet]

Re: More mysterious behavior -

CRT I know you said you checked the fuel pressure but I imagine that was at a stand still..?? yes??<br /><br />Have you looked at the VENT for the fuel tank?<br />Could be something in there clogging it up, or maybe the fitting on the tank that connects to the feed line is defaulty.<br /><br />To rule out fuel volume remove the fuel feed line and stick it in a 2 gallon gas can and take her for a spin.<br /><br />If she runs fine, you can eliviate electrical problems, and head for the fuel dept.

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

Hey flashback, rattana, merc 140 pontoon and Captain HooknFinger. Great info!!!!!<br /><br />As far as the fuel tank situation, earlier in the season one of my tanks did in fact have a clogged vent. I was able to unclog it. This current problem however, is the same regardless of which tank I run on and I switch tanks to no avail when the problem occurs. I have not tried to run on an external tank, but I will just to be certain. Maybe the pick-up in the tank gets whacky when the tanks are filled up. However, I'm puzzled as to why it takes so long to act up!<br />In any event, this is still very good information and I'll definitely follow through on it!<br /><br />As for this possibly being an electrical issue, I'm really starting to believe this is the culprit. I have not checked the resistance of the loom resistance wire, nor voltage at the coil or other voltage related things, but I must now do this! Hopefully my new coil and distributor are not flakey! I've never had a breakerless distributor like this in a boat and I don't know how they display problems. <br /><br />I also need to really have a look at the shift assist circuit. There is no doubt that this could kill the engine, but I still can't understand why it is so intermittent. <br /><br />You know the thought that actuating the trim tabs caused a voltage drop makes a lot of sense because in retrospect, it seems that the effect it had on the engine when I pushed the trim tab rocker switches, was instantaneous and the trim tabs could not have changed the "pitch attitude" of the boat that quickly.<br /><br />Something I forgot to mention, but I'm not sure it's related (other than to make me crazier than I already was): After I crippled back to the dock, I couldn't raise my drive, as the up circuit was not working. I checked the down, which was fine. I had to pull the rams and tie the drive up to trailer it home. Just for grins, I tried the up circuit when I got home and it was working. Hummm, more potential electrical issues...<br /><br />Thanks and a tip of my Skiff Craft hat to all of you guys who posted all this great stuff! I now have lots of things to contemplate tonight and tests to run tomorrow when the sun comes up. <br /><br />Wouldn't you know it, the weather is now the best it's been all year and I'm dry dock bound - again <br /><br />regards, crt

 

[loadnet]

Re: More mysterious behavior -

Sounds like you have 2 issues to deal with now that I've read your second post.<br /><br />Fuel AND electrical.<br /><br />Next time your drive won't go up or down, try wiggling your shifter around and bringing it back into neutral.<br /><br />Mine won't work correctly sometimes if the shifter is not square in neutal.

 

[kdmiller8251]

Re: More mysterious behavior -

Ok, so you installed a Mallory breakerless distributor. Did all this start happening after you installed that???<br /><br />If so then you messed something up....

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

Thanks Captain HooknFinger. Unfortunately, I think you're right. <br /><br />It's also possible that the shifter was not in neutral as you suggest. I was in a real bind coming in to the launch ramp with no power and a huge wave from somebody's wake at my back! We missed the dock and I darn near ran aground on the ramp so I was a little frantic! <br /><br />regards, crt.

 

[loadnet]

Re: More mysterious behavior -

Well ya know what Pal!<br /><br />You aren't alone out there!<br />Everyone who owns a boat has their good and bad days out there.<br /><br />Everything is always perfect till something goes wrong and the bad things like that always happen when ya least expect them to.<br /><br />After recently installing a second lower driving station in my own boat I was up top on the bridge pulling UP along SIDE a friends DOCKED boat to show off my new station and as I pulled straight up to him my engine stalled. <br /><br />No biggy right?.. I'll just start it right up again and slam her into reverse..<br /><br />WRONG!... the keys were downstairs in the lower station panel where I had first started the boat up.<br /><br />I darn near inserted my bow straight thru his Budwiser.<br /><br />Just call me quick feet... cuz I made it just in time.

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

I hear ya' Captain HooknFinger. The sea is no respector of persons and a boat can be the best and worst of times. Maybe I should name my boat "Schizophrenia".<br /><br />Speaking of quick feet, you should have seen my little dance! Drew quite a crowd and even some applause when I missed the steel pilings by a half inch! <br /><br />Maybe we should start a dance team. Quick Feet and Double Time... <br /><br />Regards, crt.

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

Hi fellow boat heads. Here's the latest:<br /><br />Checked the voltage at the coil positive lead. Well within 9 volts +/- a volt. Didn't seem to change after the engine was fully warmed. However, I realize this is all static, but I'm happy with the results.<br /><br />Here's a better one though: The engine was really running raggedy, even at idle. I checked the fuel level in the float bowl (through the peep hole) and it was definitely low. I adjusted it up and the engine ran a little better, although it was missing pretty badly. Adjusted idle mixture and it smoothed right out. <br /><br />When the problems materialized Friday, I also checked the fuel level in the float bowl and it was low and I also adjusted it up and the engine ran better for a little bit and then started acting up agian. <br /><br />Although the carb was rebuilt about a month ago, it certainly seems that the carb is at least one issue if not THE issue. My first question is, is this a typical problem in terms of the needle and seat getting worn (or whatever) to a point where you can't keep the float level happy? <br /><br />My next question is, is it possible this is actually a fuel pump issue and the float bowl is starving because of inadequate fuel supply? If I was going to ask a third question it would be, is it both?<br /><br />As always, all suggestions are extremely appreciated.<br /><br />Regards, crt.

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

Good day to you fellow mariners.<br /><br />Well, I finally gave up and took my rig into the marine doctor. I am not going to speculate what this problem is, but I don't think it's gonna be an easy nor inexpensive one. The first thing the owner of the shop wants to do is a compression test, which I have avoided since the engine will run totally on spec for a good while before this problem materializes. <br /><br />What concerns me a lot is that I had a discussion with one of the mechanics who tried to convince me that I should have 12 volts at my coil and as many of you have pointed out, that number is 9 volts. plus/minus a volt (by the way, I'm running a Mallory breakerless). I pulled the documentation on the distributor and made him read it. Fortunately, he's not going to work on it so maybe I'll be ok. <br /><br />Just for the record, one of the last things I did this week was run the boat on a lake and I checked the voltage at the coil when the engine started running raggedy. It was about 9.2 volts. <br /><br />Well, all I can do now is wait and pray for a miracle! <br /><br />Thanks to everyone who has helped me sort these issues out for the past several months. A a result of the wisdom gained here, I have gained about 1000 rpms and a ton of power. Once I get this glitch figured out, it's gonna be wonderful!<br /><br />I'll post as soon as I get the verdict.<br /><br />Regards, crt.

 

[Boomyal]

Re: More mysterious behavior -

Waiting with bated breath!

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

Well, I got the boat back yesterday. The mechanic's verdict was a bad coil secondary wire. Actually, it didn't have the correct connector end on it and wasn't reaching all the way into the coil secondary post. <br /><br />I certainly hope this is really the problem, but I have to say I'm skepticle. I can't imagine that the boat could run fine for an hour or more before exhibiting a problem with this being the cause. However, only one way to prove it out and that's to run it and that's where I'm heading now. <br /><br />More upon return - if I make it back!<br /><br />Regards, crt.

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

Well the marine doc was right! It's hard to believe, but the boat is now absolutely perfect. I ran it for several hours and it never missed a lick. <br /><br />That bogus secondary coil wire displayed some of the weirdest behavior imaginable. <br /><br />If I would have had my wits about me, I would have checked this. However, since it worked fine when I first built and installed the new plug wires, I made the bad assumption that it couldn't possible have been that. This makes me want to buy spark analyzer...<br /><br />I have to hand it to the marine doc who worked on this. I swear, when I dropped the boat off, he was talking about ignition related problems before I could even tell him all of the symptoms! It's like the guy has esp and man was it working!<br /><br />I really must post a summary about this, because the symptoms I experienced during this fiasco are so typical of other types of problems and it certainly is an easy place to start looking and a very easy one to overlook! <br /><br />In the mean time, I'm going to Lake Eire and making that run to the Detroit River I've been trying to do all summer!<br /><br />Regards, crt.

 

[rattana]

Re: More mysterious behavior -

Glad you got it fixed, you must feel great now. Think of all the stuff you learned messing with it.

 

[CRT Skiff Crafter]

Re: More mysterious behavior -

Thanks Rattana!<br /><br />You're right on both counts. I'm ecstatic that it's finally right and I learned a ton-and-a-half!!!<br /><br />Now it's off to Lake Erie for my trip to the Detroit River and beyond.<br /><br />Regards, crt.