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AQ125 wonbt start

R

runedu

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84 bayliner with AQ125 motor.

84 bayliner with AQ125 motor. Yesterday it started without any problems. This morning I go outside and it turns over but nothing. There is no spark. I figure it's a good time to convert over to electronic ignition with the hot spark. Still nothing. After troubleshooting I went out and bought a new coil without resistor and 3 ohms resistance. I briefly get it to start and then it dies like there is no fuel. When it did fire it was like it was just burning the fuel out of the carburator with no power and then it died. I do have spark but the motor is turning over like there is nothing. I'm open to any ideas at this point. tomorrow I'll check compression.
 
"The cylinders may be flooded

"The cylinders may be flooded with gas. Try to put the throttle lever at 75%-100%, try to start for up to 10-15 seconds, then be prepared to crank back to idle when you hear the engine starting so that it does not race.

Also, make sure that the accelerator pump squirts gas into the carb when you move the throttle lever.

If the compression is low, chances are the timing belt may have jumped."
 
"Thanks, it may have been floo

"Thanks, it may have been flooded. I took the plugs out and cleaned them and all of the electrical fittings. It started right up after that. I am getting some backfire out of the carb though."
 
"Check that you connected each

"Check that you connected each ignition wire to the correct plug. IF OK, check the ignition timing. And if OK, check the valve timing (the timing belt could have jumped)."
 
All the plug wires are correct

All the plug wires are correct. There are no markings on the crankshaft pulley. I don't know if they were worn off or what happened. Since I just bought this boat I don't know what type of fuel is in it. If it has ethanol and has been sitting for a year that could also be an issue. I am getting more backfire now so it looks like more of a timing issue.
 
"I ended up changing out the p

"I ended up changing out the plugs and wires and it fired right up. Actually, ran really well in my driveway. Took it out to the lake and at low rpms it ran fine. At WOT it bogged down and backfires. Open to suggestions. Thank you."
 
"I would also still consider c

"I would also still consider checking the timing as well for water in the fuel. After I installed a Pertronix electronic ignition, my distributor had to be moved 1 whole tooth cause the timing was off. Ran fine out of water with timing off, but under load it bogged and back fired."
 
What i can't figure out is

What i can't figure out is why my timing light flashes intermittently. Just to make sure it wasn't my light I put it on a car and the light flashes consistently. It looks like I will have to take it apart and check.
 
"Sid, I don't know what ki

"Sid, I don't know what kind of fuel water separator you have. If it is the one with see-though bowl type, you can see if there is water at the bottom, and you can drain it. But if it is the one that looks like an oil filter, you cannot see the water and you cannot drain it either, so once it is full of water it will eventually reach the carb.

If the timing light flashes intermittently, then I suggest it could be a problem with the distributor: points/condenser, the electronic ignition module (unlikely), the rotor or the cap, or the ignition wires. It could also be a bad coil, but you just got a new one."
 
"El,
I changed out the filter

"El,
I changed out the filter yesterday. It was one of the types that you can't see through. I've also changed the wires. I'm just going to do like JCH recommended and start from scratch."
 
"Sid,
I had similar problems

"Sid,
I had similar problems 2 years ago. Idled fine. Under load, it cut out. After rebuilding the entire elec system unnecesarily, found that the fuel pickup line in the gas tank has a mesh cartridge in the line. Mine was clogged, compressed and allowing very little gas. I removed it and have had no problems since.

You'll need to remove the sending unit to get to the pckup fuel line. A very long pair of fine foreceps or pick it out with a coat hangar."
 
"Bob,
I will check that also.

"Bob,
I will check that also. Thanks
Another symptom is fouled plugs. I pulled the new ones from my trip to the lake and they were totally carbon fouled. I installed new ones upping the heat range 3 times and within 10 minutes they are severely carboned up again. This would make it backfire and would be consistent with why it ran fan for the first hour or so."
 
"The fuel/air mixture seems to

"The fuel/air mixture seems to be too rich. Check the idle mixture and also make sure the flame arrestor in the carb is clean. If all OK, then I would look at the ignition system (weak spark) and ignition timing (6º-10º BTDC depending on whether you use regular or midgrade gas).

You should verify that the timing belt is installed correctly, and I assume you have checked the compression and it was OK (in the range of 150-175 psi)."
 
"El,

i just checked my comp

"El,

i just checked my compression and may have figured out my problem. 1-3 are fine between 160-170. Number 4 doesn't hold compression. Maybe up to a 100 then loses it. What a pain this will be. I should know better than to think it was a quick fix."
 
"Inject a bit of engine oil &#

"Inject a bit of engine oil (about 1 tbsp) in #4 through the spark plug hole, then measure compression again. If it goes up, you have bad piston rings. If no change, it could be an intake or exhaust valve not holding, or a bad head gasket.

For more accurate results, try a leak down test."
 
I retested the cylinder and go

I retested the cylinder and got a steady 125. When I added oil to it it went up to 165. Now I have to decide what to do. I'm going to see about getting a leak down tester.
 
RE: "totally carbon fouled

RE: "totally carbon fouled." and "got a steady 125"

The problem with #4 and the plugs fouling are two separete problems...
 
thanks for everyone's inpu

thanks for everyone's input. Turned out my timing was way off. I took it out today and it ran great. Now if I can only catch some fish..
 
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