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View Full Version : Trying to solve sudden 302 engine stall



fredisland
12-04-2013, 07:52 PM
Gentlemen, I have a very low hours 1991 S16 w/ 302, 2 barrel, all stock. Bought it last year with original white steel trailer and it ran great the few times we had it out until Sandy forced my hand. Put it away in non-freezing garage with treated half tank of 91 octane fuel. Did not put it in till early fall this year when I finished building new dock. Filled with fresh fuel. Starts right up and idles fine. Took her out and about 20 seconds after plane, engine dies out. Starts up and does it again. Finally brought it back at idle. Carb was rebuilt but removed and cleaned anyway. Emptied and changed Fram fuel filter. Emptied fuel in jar- no debris or water. Emptied fuel tank to dry. Pulled fuel pipe from tank and found that strainer/sock was absolutely clean. Carb strainer clean as well. So unless I missed something I've ruled out fuel.
I bought new plugs and am now looking for a special tool to change them. Man, they didn't put a lot of thought into that design. I don't think it's the plugs though.
I may have and probably did leave the key in the on position inadvertently last fall. I'm told that can effect the points.
q1. It has a factory standard mechanical fuel pump which Im told will either work or not work so that can't be it, or can it?
q2. The coil and distributor look original. Could one of those be the problem? A bad coil for example?
q3. could it be the points?
I could just start replacing things but id prefer to find the route cause and so here I am.

I'm new to the site. Any ideas?

John C in PA
12-05-2013, 12:46 AM
Hello and Welcome to the board. I have the same year Sweet 16 as you with the 302 HO motor. Your problem still sounds like its fuel related. Did you blow out your fuel lines? Perhaps some debris found its way. Boating magazine just posted a solution to a problem like yours: is youir fuel tank vent clear? Fuel pump issues are still possible. The problem doesn't sound electrical, but I have electronic ignition in mine.

For the spark plugs, I hate crawling in there too. But I found a 3/8" drive 5/8" universal deep socket works fairly well. I think I got the socket at Auto Zone and, to me, it works better than a 5/8" socket with a universal plugged into it. I can attach a pic if you want.

HTH, John C in PA

Ghost
12-05-2013, 01:31 AM
Gentlemen, I have a very low hours 1991 S16 w/ 302, 2 barrel, all stock. Bought it last year with original white steel trailer and it ran great the few times we had it out until Sandy forced my hand. Put it away in non-freezing garage with treated half tank of 91 octane fuel. Did not put it in till early fall this year when I finished building new dock. Filled with fresh fuel. Starts right up and idles fine. Took her out and about 20 seconds after plane, engine dies out. Starts up and does it again. Finally brought it back at idle. Carb was rebuilt but removed and cleaned anyway. Emptied and changed Fram fuel filter. Emptied fuel in jar- no debris or water. Emptied fuel tank to dry. Pulled fuel pipe from tank and found that strainer/sock was absolutely clean. Carb strainer clean as well. So unless I missed something I've ruled out fuel.
I bought new plugs and am now looking for a special tool to change them. Man, they didn't put a lot of thought into that design. I don't think it's the plugs though.
I may have and probably did leave the key in the on position inadvertently last fall. I'm told that can effect the points.
q1. It has a factory standard mechanical fuel pump which Im told will either work or not work so that can't be it, or can it?
q2. The coil and distributor look original. Could one of those be the problem? A bad coil for example?
q3. could it be the points?
I could just start replacing things but id prefer to find the route cause and so here I am.

I'm new to the site. Any ideas?

Welcome to the board. Don't know about points and coil, others here will I expect. Sound like good questions to me.

Have trouble believing an original distributor cap and rotor could still be good. Mine seemed to need swapping within 3-5 years. Not sure if that even fits your symptoms, but I suppose maybe. When mine were going bad (on an EFI motor) it would run fine if it would actually start. Starting was the hard part.

One question: couldn't tell for sure when the carb rebuild took place in the timeline. Has the motor ever run properly since the carb was rebuilt? Could it be totally out of whack in some way? Just speculating.

mattyboy
12-05-2013, 07:44 AM
all good suggestions

I am always of the school of thought if it worked and now it doesn't what changed? the carb

I would take a small red gas can used for an OB rig it up to your motor and test that will let you know if it is fuel delivery from the tank or a motor issue

is the dist mechanical or vacuum advance?

on my 16 I had a stubby box end wrench and a full length box end wrench that had the open end cut off so it fit

good luck I am sure you'll get it figured out

welcome to the madness

fredisland
12-05-2013, 09:51 AM
Gentlemen,
Thank you all very much for the interest and insight. You've given me several things to follow up on which I plan to do over the weekend. Here I am a new member and the first thing I do is ask for help! Once "we" get this thing solved, I will post the results and list the things done in the process so maybe it can help someone else down the creek.
Separately, I'll get the boat registered with pis(s). I look forward to sharing how this purchase came about and hope to make the Lake George outing in 2014 if fate shines.
Stand by…..

tmdog
12-05-2013, 09:58 AM
Fuel pump

mattyboy
12-05-2013, 03:21 PM
Gentlemen,
Thank you all very much for the interest and insight. You've given me several things to follow up on which I plan to do over the weekend. Here I am a new member and the first thing I do is ask for help! Once "we" get this thing solved, I will post the results and list the things done in the process so maybe it can help someone else down the creek.
Separately, I'll get the boat registered with pis(s). I look forward to sharing how this purchase came about and hope to make the Lake George outing in 2014 if fate shines.
Stand by…..


Let me know if you need any info on the LGDCC events

good luck

Christian
12-05-2013, 09:37 PM
All great ideas by board members.

I would start with the easy possible solutions. prior to hooking a new fuel tank (great idea) I would make sure the vent line is clear. It should be an easy step with compressed air. BE SAFE. Next, if the prob persists with a temp fuel tank, it could be a fuel pump. At this point I would be less likely to suspect an ignition problem until you can make sure the motor is getting proper fuel.

All great ideas coming from the board. this place always comes to the rescue.

good luck!

hardcrab
12-05-2013, 09:52 PM
possibly sucking air - vacuum hose?

Pismo
12-06-2013, 09:05 PM
Spray Gumout down the carb while it is dying. If it runs perfectly for 10 seconds of so then it is clearly a fuel problem. Gumout, not ether. If it still does not run, thenit is ignition.

MOP
12-09-2013, 05:54 PM
Unless someone changed things out you have electronic ignition. Fuel may be a problem but going over your things done has me thinking. Check the pack ground where it bolts to the riser, also look over the shift interrupt wiring. Try another coil but I don't think it will matter, when they go bad they are usually DONE. If the coil over heats it will not readily restart.

Quick add on also the key switch is a possibility, watch your gauges see if they drop showing no voltage. My two cents it will be an electrical gremlin.

Phil