86 Mariner 3297 Electrical/Engine Issue

Hey Niles, good idea. Might try this. I actually replaced them myself so I know what and where to get at them. Although it was a pain to get the hose on and off those barbs... :)

meide, I don't think I have engine control modules on my 1986 engines. I could be wrong, but I don't believe they have them. cmariner can you confirm?
 
I have freind that fought the screen issue. It was a new boat and I guess "whoever" left a bunch of shaving in the tank and they would get sucked up onto the screen and cause the same conduition you have.

When they pulled my pickup tubes they found a huge spider body in it. The yard kept it on display for the longest time :)

Niles
 
Spider probably fell in exploring the vent tube and at some point it got sucked up in the pickup tube and got stuck.
Niles
 
I didn't think so.

New news... now I am having a similar issue on the other engine... So we are attacking the fuel lines and tanks this week. Going to remove the screens on the pick up tunes in the tank, add another filter on the outside that we can visual inspect over time, and then bypass the switch over valves and go straight to the filter on the engine (one tank to each engine). So simplify the setup and monitor the filters closely to see if its in the tanks or if it was the lines to and from the switch over valves. Also going to re-route the fuel lines to take away any chance of vapor lock.
 
Just a follow up on this. Other engine is back to normal now, that was definitely a fuel line issue. Original engine (starboard) issue remains though. I think we have stumped a second mechanic on this....
 
Tell the mechanic to go back to his basics. An engine needs 3 things to run, spark, fuel and air. A fuel pressure gauge will determain that, you know you hae air, the carb is opening and there isd a spark tester you can install and run it to see if it's misfiring or not sparking at all!
 
Ya, that is exactly what our plan is for this weekend. We have replaced so many things that my thinking is that it may just need to be "dialed in" and that the problem is just that things aren't tuned just right. Unfortunately for this current mechanic, he wasn't part of all the stuff we did last season, so he is going on what I have told him. Also, a lot of the time with the previous mechanic, I was up at the helm driving while he was in the engine compartment so I can't see what he did specifically.

So, he is doing a quick check on the carbs this week. Then on Sat. we are going to step one and go through everything to make sure things are tight, screwed, tuned, checked, and whatever else he can think of. I keep thinking we are over looking something really simple because we are trying so hard to find a "smoking gun" when we may have already found it, just didn't tune it in. Like maybe running too lean or rich now or something else simple.
 
Replace pug wires. United out of Cleveland, Ohio. High voltage out puts breaks down plug wires. This miss would come and go ( 50 to 75 rpm ) and get worse when engines were run for long periods of time. Test fuel problem with a small isolated tank. My 2 cents.

Ron
 
Hey Ron, already replaced the plug wires, plugs, and dist. cap. Also put in electronic ignition kit in them and got rid of the points.

I have thought about the isolated tank idea, problem is it takes a certain distance for the problem to happen and I would need a large enough tank to hold the gas. Plus, I have 2 tanks already and I am able to switch between them and the problem remained when I flipped them. So I ruled that out with the exception of the individual line that runs to the fuel filter on the engine. I am contemplating taking a line and running it directly from the tank to that filter and bypassing the switch over valve and lines altogether depending on what we find this weekend after we go through everything with a fine tooth comb to make sure everything is tuned/tweaked properly.
 
Long story short, we finally got the problem fixed... turned out to be some faulty electronic ignition kits (Pertronix). Replaced them with full GM ignitions and coils and she is running awesome... Three years and 3 mechanics and the final guy figured it out within 2 weeks. God send! Now we can finally enjoy the boat without worrying...
 
Glad you finally solved the problem. I had points on my '86 Mariner and thought about upgrading to electronic ignition, but was advised by GVP that if I knew how to install and maintain points and condensers, I'd be much better off. I kept the points for the 10 yrs. that I had the boat. My Santego has the Prestolite breakerless ignition systems-so far so good-but I bought a backup module for if and when.....more likely when...it fails. Enjoy your season!!!!!
 
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