four banger volvo wont start up and run

Trying to get this thing up and running and back to how it was two decades ago isnt easy and i've used this forum plenty before registering so i know i will probably get some very useful info. This deck boat is an 89 deck boat with a 4 cylinder. I have no clue what actual model it is becuase the previous owner switched the motor out and is no longer around to let me know. I bought it from my cousins neighbor who inherited it when his dad passed. I am a car mechanic with about 10 years experience so i have checked everything i can think of before asking for direction. The head was JUST rebuilt with all new parts (still very clean aluminum when looking in from the oil fill cap), the timing is dead on the money, compression is good, distributor cap is new, rotor is new(im not sure what the boating world calls them but on cars its called a rotor inside the distributor), plugs are brand new volvo plugs, wires are so-so but are firing because i checked with an inline spark tester. I can dump gas in the carb and it attempted to fire a couple times but never busted off. My gas tank is full of NASTY old gas and im in the process of cleaning it out to reinstall which is why i have to dump the gas in the carb. My question is, if the motor has sat unstarted for at least a year could it just be that it takes an unusual amount of time to bust off or is there something anyone can recommend for me to check that i have overlooked? Any help would be great!!

Re: four banger volvo wont start up and run

Dude, open up the carb and look for corrosion, dirt, and nasty old gas.

Re: four banger volvo wont start up and run

i took apart the top of it today. the bowl has very little sludge in it which i am going to clean out wednesday when im out there again. my biggest confusion about that is i wasnt even really using the carb except for air because i was dumping gas directly in the carb. it was my original thought also though.

Re: four banger volvo wont start up and run

Do you have spark? You really need to figure out what engine you have if you ever want to get it right. Post some pictures, look around the starter and fuel pump for a metal tag with some Volvo numbers.

Re: four banger volvo wont start up and run

You say you have spark (properly timed) and air so you need fuel.

Clean the carb and then run a fuel line from a can with fresh fuel to the fuel pump. Confirm you have a functioning pump by using clear line and watching the fuel movement in the line. You may have to prime the pump.

Re: four banger volvo wont start up and run

I believe its timed right but cant be 100% certain until its running. I have tried moving the distributor a little but moved it back to where it was when i started. The motor i believe is an aq125 based on the extra motor that came with it. The motor installed does not have any tags on it. Im going to try cleaning the carb tomorrow morning and ill run a gas line to a fuel tank with a primer on it. Ill let you know what happens!! Thanks for the insight

Re: four banger volvo wont start up and run

89ravendeckboater said:

I believe its timed right but cant be 100% certain until its running. I have tried moving the distributor a little but moved it back to where it was when i started. The motor i believe is an aq125 based on the extra motor that came with it. The motor installed does not have any tags on it. Im going to try cleaning the carb tomorrow morning and ill run a gas line to a fuel tank with a primer on it. Ill let you know what happens!! Thanks for the insight

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You can be certain that it's close enough to start by bring #1 cylinder to TDC, remove the distributor cap and make sure the rotor is pointing to the mark on the distributor body that denotes #1. That's close enough to get it running.

Re: four banger volvo wont start up and run

Did it run before it was left to set?? Is the firing order correct? Is it the Correct diszzy cap and rotor? (the real ones are $$$$$ so many try to make auto ones work, and fail)

Good Luck.

Re: four banger volvo wont start up and run

no704 said:

Did it run before it was left to set?? Is the firing order correct? Is it the Correct diszzy cap and rotor? (the real ones are $$$$$ so many try to make auto ones work, and fail)

Good Luck.

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I'd love for someone to explain to me what makes a boat distributor cap different from an auto cap....other than the gouging price.

Re: four banger volvo wont start up and run

Not so much the cap as it is the distibuter and cap assembly.
An auto cap/dist does not concern itself with being air tight.
The boat cap/dist has only one vent, in the dist with a screen to prevent fuel vapor, ( say from a dripping line) from mixing with the little spark at the plug points.

So, the dist cap will not have a vent hole, the dist has only one with a screen/valve type arragement.


but we've drifted off course.

OP, you wrote you have some mechanical ability, does the engine appear to have an overhead cam ?
Are the plug wires flexible or stiff and old needing replacement.
Is there a capacitor mounted to the outside of the distributer.

Static timing should get you to a running condition if all else is good.

Re: four banger volvo wont start up and run

It was not ran before being set up but all parts are brand new and installed at a marine mechanic shop here locally. It is an overhead cam engine. The wires are very stiff and old but the still are sparking (maybe not enough, but they are sparking), I put an inline spark tester in between the wire and the plug on all 4 to ensure it was firing. Yes, there is a capacitor mounted outside the distributor. Im going to set the timing up first thing tomorrow and have another run at it. Thanks for all the input guys!!

Re: four banger volvo wont start up and run

89ravendeckboater said:

It was not ran before being set up but all parts are brand new and installed at a marine mechanic shop here locally. It is an overhead cam engine. The wires are very stiff and old but the still are sparking (maybe not enough, but they are sparking), I put an inline spark tester in between the wire and the plug on all 4 to ensure it was firing. Yes, there is a capacitor mounted outside the distributor. Im going to set the timing up first thing tomorrow and have another run at it. Thanks for all the input guys!!

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As mentioned...check the firing order. Rotor turns clockwise.

Re: four banger volvo wont start up and run

got her to fire up briefly yesterday. the carb has to be rebuilt for sure. put new fuel in a tank, primed the system and used a little ether to give it a little assistance and it fired up but the card was dumping way too much gas in and flooded it. I tore apart the side of the carb and there was a little ripped screen and plenty of sludge so for preventative maintenance and overall performance ill have the whole thing gone through and rebuilt. I dont want to get on the water and have a tiny piece of trash cause a bunch of issues.

Re: four banger volvo wont start up and run

89ravendeckboater said:

got her to fire up briefly yesterday. the carb has to be rebuilt for sure. put new fuel in a tank, primed the system and used a little ether to give it a little assistance and it fired up but the card was dumping way too much gas in and flooded it. I tore apart the side of the carb and there was a little ripped screen and plenty of sludge so for preventative maintenance and overall performance ill have the whole thing gone through and rebuilt. I dont want to get on the water and have a tiny piece of trash cause a bunch of issues.

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Smart...don't forget an inline fuel filter. Preferably one that has a clear case.

Re: four banger volvo wont start up and run

Never use ether or any other starting fluid, stick to straight gasoline.

Re: four banger volvo wont start up and run

biggziff said:

Smart...don't forget an inline fuel filter. Preferably one that has a clear case.

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DO NOT use one of these plastic clear filters! They are not coat guard approved and are a HUGE fire danger for an inboard!

Instead, install a fuel filter /water separator between the tank and fuel pump. Like this: http://www.iboats.com/Water-Separat...00298479--session_id.125954215--view_id.45101

Have you figured out what motor this is yet? Here is a crappy small pic (all i have with me) of my aq125a for reference

If it is and you have the single barrel solex 44 pa1 carb on there like mine, then that ripped screen was your accelerator pump diaphragm. Get a rebuild kit and about 3 cans of carb cleaner. It's pretty simple and quick to work on.

You have Volvo plugs? Oddly enough, when I bought my boat it had volvo plugs in it too, they didn't match the correct Bosch W6DC plug that was supposed to be in there and it starts like a charm with the correct plug. The old owner had at least two cans of starting fluid on the boat because the volvo plugs where too short and didn't get into the combustion chamber like they should.

As for the difference between auto and marine, it is basically the containment of any spark that is important. Your motor is in a fiberglass motor enclosure that traps all the fuel vapors, holding them until either you run the blower motor, or a spark gets it and burns up your boat. The main components like the starter, alternator, and distributor all have spark arrestors on them compared to an automotive equivalent. Also, the mechanical fuel pump has a separate return line to the carb.

You will have to get the motor up and running at operating temp (180F) before you can check the ignition timing and dwell.

Post a pic of the boat and motor.

Re: four banger volvo wont start up and run

Mullin said:

DO NOT use one of these plastic clear filters! They are not coat guard approved and are a HUGE fire danger for an inboard!

Instead, install a fuel filter /water separator between the tank and fuel pump. Like this: http://www.iboats.com/Water-Separat...00298479--session_id.125954215--view_id.45101

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So can you explain to me what makes them a fire hazard for a boat when they work fine for all kinds of other applications?

Re: four banger volvo wont start up and run

TyeeMan said:

Never use ether or any other starting fluid, stick to straight gasoline.

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Whats wrong with a little ether to help it fire? worked great on cars that need a little boost and worked well with this one. I dont use a bunch just a little squirt.
My motor is just like the one in the picture and i will probably change the plugs out to bosch ones if that is what it calls for and i found out today while doing some research that it was the accelerator pump diaphram so i ordered a rebuild kit. No one i called in town had one which surprised me because i live right on the water in florida!
thanks for all the help!

Re: four banger volvo wont start up and run

89ravendeckboater said:

Whats wrong with a little ether to help it fire?

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I know 2 strokes and ether are a no-no, but we've always used ether on 4 strokes...I'd like to know why the OP thinks it's a bad idea as well.

Re: four banger volvo wont start up and run

biggziff said:

So can you explain to me what makes them a fire hazard for a boat when they work fine for all kinds of other applications?

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The thing is that an inboard is in a contained area.

On a car, imagine the plastic cracks and it leaks a little gas. No big deal as it will leak out onto the street and the fumes are not contained either. Sure it could cause a fire but the fresh ventilation for the car motor makes it a lot less likely.

On a boat, that fuel will just pool in the bilge area. The fumes have nowhere to go. So not only do you have gas sitting in the back of the boat but the fumes collect and can be ignited by a spark, hence the addition of spark arrestors on everything electrical on a boat motor.

Use an inline metal filter, just to be safe.