AQ125A will not run right

[83 Capri]

I have an 83 AQ125A/Penta 270. Initial issue was that the motor would load up and miss after idling for a long time. It would sputter but would eventually clear out and run right. I did carb rebuild and no help. Figured out the carb was leaking fuel because the emulsion tube was loose in the housing. I replaced the card from Flying fish Carbs and now the problem is different. Now it will sputter when you try to accelerate and below 3k rpm it would run for a second and then drop rpm and stall. It ran fine over 3k, wierd. A couple quick pumps of the throttle can usually get it to accelarate. I thought accel pump, but there is a steady stream off gas when you move the throttle. I thought it was running lean so i richened it and no help. A buddy said maybe it is running rich. I leaned it out 1.25 turns from the setting from Flying Fish and it seemed like my issue was fixed. No bogging from idle and could maintain whatever rpm i set the throttle at. Took it to the lake and she ran great. Happy day!! Second trip to the lake, Not a Happy day!!! It was hard to start, it would fire and run for a second and die. Once i got it running and warm i left the dock. She didn't want to rev up. I got her up on plane and runnning for a while and thought everything was better. I sat for a while and fished, fired her up and went to take off. She got up on plane and cruised for a while and then lost rpm. It would slow way down, without moving the throttle and surge. if i didnt pull back on the throttle it would die. I think it is a fuel pump issue but it is brand new. Does anyone have any ideas about what might be happening? Also does anyone know a good electric fuel pump option? Sry for the novel. This is driving me crazy and i might just sell it but would loose my a#$ because it wont run right Thanks guys

 

[RogersJetboat454]

Re: AQ125A will not run right

Lets start with the basics to be sure you are not covering up another issue by fiddling with the carb...

Have you done a recent compression test?
Has it had a recent tune-up with points, plugs (correct plugs), etc?
Is the ignition timing and dwell set correctly?
Fuel filters/water separators have been cleaned or replaced?
Any water in the fuel?
When is the last time you did a timing belt?

 

[83 Capri]

Re: AQ125A will not run right

Lets start with the basics to be sure you are not covering up another issue by fiddling with the carb...

Have you done a recent compression test? 126.5-127 psi
Has it had a recent tune-up with points, plugs (correct plugs), etc? I did plugs last year (NGK BP6ES) checked them this year and they look good. Also did wires and cap and rotor last year
Is the ignition timing and dwell set correctly? Have not checked timing this year but on the list. It has a points eliminator kit.
Fuel filters/water separators have been cleaned or replaced?New fuel filter, it doesnt have a water separator (any suggestions on one, i am afraid it will be too much resistance for the mechhanical pump
Any water in the fuel?I havent noticed water in the carb float bowl, i run ethanol treatment how can i chack the tank for water?
When is the last time you did a timing belt?I haven't done the belt but i have one. It looks ok,

Went outside and started tinkering after the post. She started right up no issues and idled fine. A lil hesitation on accelaration but she wasnt warm yet. I checked the float bowl and full of fuel. No water in the bowl. Could it not be fuel related at all? I'm stumped.

 

[RogersJetboat454]

Re: AQ125A will not run right

You say you have a conversion in the distributor, so that rules out points, but the one issue those conversions don't address is if you have worn out distributor shaft bushings or an issue with the mechanical advance such as frozen weights, or busted/weak springs for the advance.

I would check the timing. If the timing light is showing your timing bouncing around suspect the above. May be worth physically looking in the distributor and checking to see that the weights are free, and the springs are still together and have some resistance.

Since you are eventually able to get this up to WOT (what is your WOT RPM BTW?), it doesn't sound like a supply issue or water in the fuel, but it still may be nice to have a fuel sample. I have no easy answers for you on how to get this. Don may know better. The banjo style fittings Volvo used would make it a pain in the butt, but if it were me, I would pull the fitting off the carb and try my best to rig up something so that you can get all the fuel coming out the line into a large clean bottle for a sample. Have some one crank it over, and have a look at the contents of the bottle.

Rebuilt/re-manufactured anything isn't always perfect either. Sometimes they don't get it clean enough, sometimes they miss the worn out this or that, sometimes the float is set wrong, or a part they put in just doesn't work right. Its a possibility the carb you received may still be an issue. After all, someone returned it to that carb service as a core when they were having problems with it. Not to say it IS the problem, but after you have ruled everything out keep all that in mind.

As far as the T-belt is concerned, if you haven't replaced it, and don't know when it's been replaced, it would be a good idea to change it out. T-belts are wear items, and quite honestly are good at hiding wear. As you are probably aware, a stretched belt will change your valve timing which can affect the performance of the engine. A broken belt will ruin your day on the water. Again, not saying this is your silver bullet, but should be considered for replacement.

 

[83 Capri]

Re: AQ125A will not run right

The weights and advance seem to move freely. i can move it by hand and let go and it snaps back. I will check the timing at idle and i think it is 4200 rpm. the manual has the exact number it's just not in front of me. As far as the timing bouncing around, will that be caused by worn Dist bearings or just the weights and spings? Can i check the Dist for to much play with it installed or does it have to be removed? WOT is about 4800 to 5 k. On smooth water it will eventually get to 5 k. is this normal. I normally cruise around 3800 to 4k. The carb may still be the issue, it was rebuilt for a reason. Lukily it has a lifetime warranty and they already said they would replace it if i could not get the boat running right. I was definitely sad to see the stock one go. I will replace the timing belt and see what happens. Thanks a bunch for the insight and i will let you know what i find. Wish me luck

 

[RogersJetboat454]

Re: AQ125A will not run right

As far as the timing bouncing around, will that be caused by worn Dist bearings or just the weights and spings? Can i check the Dist for to much play with it installed or does it have to be removed?

Primarily worn out shaft bushings, but if you had weak springs that could allow the weights to bounce around, that may be a contributing factor.

Can i check the Dist for to much play with it installed or does it have to be removed?

You will know the story when you put a light on the timing pointer. If it is bouncing around, I would send it out to a distributor shop for them to look over. They would be the ones to replace the shaft bushings, and also have the proper equipment to test the advance curve for your mechanical advance.

WOT is about 4800 to 5 k. On smooth water it will eventually get to 5 k. is this normal.

Sounds like the right RPM range for a 4 banger.

The carb may still be the issue, it was rebuilt for a reason. Lukily it has a lifetime warranty and they already said they would replace it if i could not get the boat running right. I was definitely sad to see the stock one go. I will replace the timing belt and see what happens. Thanks a bunch for the insight and i will let you know what i find. Wish me luck

Sounds like a good place. Like I said before, not too uncommon for old carbs to have to be rebuilt again. Some trash in the idle circuit of the carb you received may be the culprit, but again I would rule out all the variables with the boat before sending it back.

Good luck

 

[83 Capri]

Re: AQ125A will not run right

So I finally got back to working on the boat. I fixed a voltage regulator that was giving me fits and was able to get the timing checked. It is indeed bouncing. It never sits still and is actually advanced a little. From Rogers last post, i guess i am pulling the distributor. My issue now is, the sucker wont budge. It was a ***** to rotate to set the timing. Am i missing something, there is only one bolt and it wont budge. Do you have any pointers?

 

[RogersJetboat454]

Re: AQ125A will not run right

So I finally got back to working on the boat. I fixed a voltage regulator that was giving me fits and was able to get the timing checked. It is indeed bouncing. It never sits still and is actually advanced a little. From Rogers last post, i guess i am pulling the distributor. My issue now is, the sucker wont budge. It was a ***** to rotate to set the timing. Am i missing something, there is only one bolt and it wont budge. Do you have any pointers?

Soak where the body of the distributor meets the block with PB blaster, and let it sit for a little bit. Then wiggle it back and forth while occasionally spaying more PB in that area until it frees up. Once freed up, wiggle back and forth while pulling upward.