aq125 stalled

[therl]

My engine stalled twice this weekend and would not start back up immediately. Once I parked it for a couple hours then it fired right up and the second time I was waiting to trailer it and it wouldn't start for about 20 minutes. Any ideas? I did notice after I got home that there seemed to be a lot of oil in the flame arrestor and on top of the carb. It's a 1983 bayliner 1950 with the aq125/penta 270 setup.

 

[jerryjerry05]

Do a compression test and post the results.
Check the timing and the plugs.

 

[therl]

Thanks Jerry. I don't have the tools to read compression or a timing light. I was planning to borrow them and get that done but I decided to look at the spark plugs first. I took them out. They didn't look too bad but I cleaned them up and put them back in. Then I loosened the distributor. Thought I might just start it and see if I could adjust it a little to see what happened. I hadn't move the distributor just loosened the bolt but the boat wouldn't start. Just puffed out of the carb and then a backfire. Not sure what happened. The boat was running in the driveway pretty well right before I cleaned the plugs and it had been running pretty well for the last couple years - except for the two stalls that weekend. It actually seemed to run fine in between the stalls for awhile too. Anyway, I decided just to start over on the timing. I took the distributor out and tried to move the engine to TDC. According to the book I have you can take the oil cap off and tell TDC by the way the cam is situated. Well, when I see the cam in the proper position the timing mark is at least 10 degrees off.

1. What would cause that? - Pretty sure the engine has never been apart.
2. If I make a new mark and use that could I time it from there?
3. When I put the distributor in should I have the engine at TDC or at the suggested time of 10 BTDC?

Thanks for any advice.

 

[captmello]

With all due respect, you'd have been better off just following jerry's advice. If you're sure you've got the engine #1 at TDC on the compression stroke, install the distributor so the the rotor is pointing towards or just before the #1 spark plug wire on the dist. cap. The motor should run in this position, allowing you to check it with a light. Dont try to adjust it by ear, your wasting your time. I would suspect your points may need replacing along with the condenser as well. A compression check can give you a hint about the overall health of the motor and often give you a hint about the timing belt if it has jumped a tooth. Those motors have a reputation for needing to be well tuned and maintained to perform well. If you decide to change the points, use a dwell meter and adjust the timing after setting the points.

Good Luck!

 

[therl]

Thanks. TDC and the 0 mark actually do line up. The picture of the cam position had thrown me off but I have since checked that the piston is indeed at the top. I was trying to follow Jerry's advice. The first thing I could do was check the spark plugs because I was going to have to borrow the tools to do the other. Problem is, after checking an re-installing the plugs I went from a boat that started as soon as you touched the key to a boat that was backfiring when you tried to start it. I did loosen the distributor bolt but didn't move it and you can clearly see where it was because there are marks from where the washer was pressed against metal. I'm not sure why anything I did would cause it to do that but I couldn't really check the timing after that. I have purchased NGK plugs to replace the Champions that everyone hates. I still need to get tools to check the rest.

I meant to mention this in the first post...Outside of the 2 mystery stalls the boat has been running well for the last two years after replacing almost everything that's connected to the motor - points, plugs, wires, coil, fuel pump, rebuilt carb, etc. The only thing that seemed a little off to me was that I thought it was idling a little high and the carb adjustments were nowhere near what were called for in the book. I could only turn the idle screw in about 1/4 of a turn and the mix screw out about 1/4 turn. They call for 1 - 1 1/4 turns if I'm reading the book correctly. I'm not even sure it that would be a symptom of off timing but I never had a gun to check. Guess I should have start there before messing with anything else but I got a little anxious to get it going. Figured if I could tell a difference just by tinkering with it then I would at least know if it was bad timing or not....then I could fine tune it with the gun.

 

[captmello]

Any chance you mixed up the wires? Sounds like your getting some spark since its backfiring. Bad timing will cause backfiring...I would check the points. Not restarting hot could be a carb problem, but I'm not an expert on those carbs. or perhaps the coil is overheating and needing to cool down or is now shot. Do you have the old coil you took out two years ago? What is the voltage at the coil + side with the key in the on position? If you rotate the motor to TDC on the compression stroke, is the rotor pointing at the #1 spark plug? I still can't tell if you're on the compression stroke...

 

[therl]

Thanks again. I think I do have the old coil. Coil overheating and vapor lock were the two things that I have come up with just from reading...but never had that problem in the last two years. I installed the new plugs and put the distributor back in. I'm back where I was. It's firing right up. I just a can't adjust the carb anywhere near specs without it running over 2000 rpm. I'm trying to get my hands on a dwell meter and timing light today. I know I should get the dwell right then look at timing but if the carb settings are not good would that affect the dwell reading/setting or is they not dependent on each other?

 

[captmello]

Carb doesnt care about the dwell. but the dwell must be done before timing as it will change the timing. Boats with vapor lock should simply be able to remove the fuel cap if the vent has somehow clogged.

 

[therl]

OK. I put the dwell meter on and it's reading at 10 when it should be 62. Is it possible to be that far off if I've gapped the points as accurately as I could with the gauges or am I doing something wrong? Black to ground - red to coil prong that goes to distributor. Just want to see if that's possible before I go too far in the wrong direction.

 

[therl]

Additional Information -- After adjusting the points and not seeing any difference I happened to notice that the meter is moving to about 10 degrees when I turn the key on and not moving when the boat starts. Do I have it connected wrong or do I have a bad meter?

 

[captmello]

Assuming you've got the meter set to 4 cyl., sounds Odd...the red lead should go to the - coil terminal and the black to ground. I recall setting my points initially with a feeler gauge, then using the meter and finding the dwell to still be way off. I set it with the meter and the boat ran great. Keep at it!