Logo
FULL SITE MENU

aq125a, low rpm problems

P

parkerjoe19

New member
hey guys, i have an aq125a that runs strong all day at high rpms. but when i bring the rpms down to trolling speeds 1000-1200rpms, after awhile when i want to pick up and move spots she spudders spits and wont get on plane. this is the 2 motor i put in this boat, the first motor did the same thing. the 2 motor ran great till the end of the year. any ideas? thanks
 
Sounds like a fuel related problem to me and could be one of these issues.

1- Gasoline bad
2- Fuel Filter clogged
3- Fuel tank vent clogged
4- Crud in fuel tank clogging carb
5- Water in fuel

If it was me I would take a 2 gallon can of fresh gasoline on my next trip and if it acts up again put the hose from the fuel pump that normally goes to the boats gas tank into the 2 gallon can and see how it runs on fresh gasoline. If it runs OK drain your fuel tank and refill with fresh gas.

Good Luck
 
parkerjoe19 said:
hey guys, i have an aq125a that runs strong all day at high rpms. but when i bring the rpms down to trolling speeds 1000-1200rpms, after awhile when i want to pick up and move spots she spudders spits and wont get on plane. this is the 2 motor i put in this boat, the first motor did the same thing. the 2 motor ran great till the end of the year. any ideas? thanks
Click to expand...

I have the AQ125a also it it does the EXACT same thing. I rebuilt the carburetor, flushed the tank, replaced all gas lines, replaced the fuel filter, reset spark timing, gapped pluggs, reset timing advance to spec...and it still chokes out at partial throttle setting. If you hammer it to WOT, it's fine; but I absolutely cannot gingerly accelerate through the RPM band.
 
Add a bad anti-siphon valve to Olddawgs' list. The sputtering at acceleration also makes the accelerator pump suspect. Take the cover off and watch for fuel spray from the accelerator pump nozzle. If it's not pumping, then there's obviously something wrong. The idle circuit is rather intollerant of varnish or crud in the carb. You really need to LOOK and see what it's doing. Make sure you check the accelerator pump linkage as well.
 
you got to watch that anti-siphon valve those things varnish, i usually pull mine and soak it to clean it. Not only when u accelerate should it come out the high-speed jet it should also squirt out that upside down J tube, those plug up to, that helps with the extra oomph to get it going. Just don't slam those things into wot when the engines cold, tempermental engines when there cold. Mines tempermental until it reaches 180. Theres a little tiny screen in those carbs that get dirty too..
 
parkerjoe19 said:
hey guys, i have an aq125a that runs strong all day at high rpms. but when i bring the rpms down to trolling speeds 1000-1200rpms, after awhile when i want to pick up and move spots she spudders spits and wont get on plane. this is the 2 motor i put in this boat, the first motor did the same thing. the 2 motor ran great till the end of the year. any ideas? thanks
Click to expand...

Check if you are getting a lot of blow-by gases from the cylinders sucked into the carb when at idle. The blow-by gases reach the carb via the hose connected between the carb flame trap cover and the oil trap in the cylinder block. If excessive blow-by, the cylinder walls and piston rings may be worn, in which case you may have to rebuild the engine.
 
Back
Top