Aq125 issues

[singledoubt88]

So my buddy just bought a 85 bayliner capri with a aq125 and a 270 drive on it, we splashed it for the first time, and noticed a couple problems.

I own an outboard I'm just not very versed in I/O's. Any help would be greatly appreciated! The boat idled well on muffs.

1.) when on plane at around 3k rpms it's feels like the prop is slipping. It will not bite pass 3k and accerelate the boat , although the motor hits WOT at 4800. Didn't have my gps on me but we probably topped at around 18 mph.

2.) After cruising at 3k for awhile we noticed steam from under the cowling, and removed it revealing antifreeze boiling from under the cap. We then shut it off let the steam pass and headed for the dock. The motor temp never exceeded 190 and averaged 185.

Just wondering a good place to start on these problems.
Thank ya fellas

 

[kmarine]

Re: Aq125 issues

sounds to me like two seprate issues.
1. replace seawater pump impeller I believe you are not geting enough cooling. check closed cooling heat exchanger for proper flow.

2.You may have a spun propeller hub.

 

[singledoubt88]

Re: Aq125 issues

Thanks for the quick response kmarine.

I'll check the heat exchanger this evening, I removed the strainer and it wasn't clogged. It there a preferred way to diagnose proper flow?

I had my suspicions about the prop hub being spun. The boats currently stored 45 mins away from the lake, so marking the prop and checking it after a test drive would be kind of cumbersome. Is there another way to determine if the hub is spun?

Thanks again for the help!

 

[no704]

Re: Aq125 issues

^^^^ What kmarine said, I have the same in an '86. had a spun prop and could not tell at all other than to load it. you can get them re-hubed, but I just bought a new one for around $70. For sure put a new impeller in, cheep and easy. Also check the pick up hose off the outdrive, the housings really like to rot out. While you are there make sure to check out the drive Bellows for leaks. You can destroy the output shaft bearings really easy if you have a leak! (don't ask how I know)

Good Luck!

 

[werty1188]

Re: Aq125 issues

Hey im the guy who bought the boat. Looks like im going to be buying a new prop. Id like to use the boat mainly for skiing,tubeing ext. and will prob have at least 4 ppl on the boat most of the time. What type of prop do you recomend. 3 blade vs 4 blade and pitch size and dia. Any input would be greatly appreciated. First time boat owner

 

[Bondo]

Re: Aq125 issues

Hey im the guy who bought the boat. Looks like im going to be buying a new prop. Id like to use the boat mainly for skiing,tubeing ext. and will prob have at least 4 ppl on the boat most of the time. What type of prop do you recomend. 3 blade vs 4 blade and pitch size and dia. Any input would be greatly appreciated. First time boat owner

Ayuh,... Welcome Aboard,... That question can be answered in the Prop forum,...

When ya get there, read the "Read This First" thread, 'n answer those questions in yer post...

 

[werty1188]

Re: Aq125 issues

Thanks bond-o,

The performace issue im trying to correct is in the first post. I dont know the current model # or manufacturer of the prop i have now but it is an aluminum 14x17R. The WOT was about 4800 RPM but felt like prop was slipping and was only going about 15 mph max. Boat is a 1985 19' Bayliner capri w/ 4cyl volvo penta 2.1L 125HP w/ 270 outdrive.

 

[werty1188]

Re: Aq125 issues

I also would like to know how you can tell if my boat has a short hub sterndrive or a long hub sterndrive. Thanks!

 

[Mullin]

Re: Aq125 issues

The prop section is the best place to ask, but since I went through this with my '85 capri I can tell you the only way to know if you have the short or long hub is too measure it. You take off the prop and measure, it's either 4.7" or 5.4". Look around and you'll find an illustration showing exactly how to measure it.

What prop? depends on so many things like the weight of the boat, the altitude you are at, how well the motor runs etc, that the only real answer anybody can give you is, try a prop and adjust from there. That's it.
You probably have a 3 blade 14x17R now and that is probably what you should keep. The motor isn't very fast to begin with and a 4 blade will knock off some top end speed.

My 18' gets up to just 28mph, but I am at 6700ft elevation. I have 19 17 and 15 degree props, it over-revs just a tad with the 15 up here if I don't have anybody with me. I'm going to take it off the mountain next weekend for the first time, I plan on using the 19 at see level, we'll see.

The motor should run at 180F and not much more. Like said before, change the impeller on the front of the motor. You can back flush the outdrive with a garden hose to see if water squirts out where it is not supposed too, showing you where you have an air leak. If you have an air leak then the impeller will pull air instead of water from the bottom of the leg. Also, if you run it on muffs, notice that there is a hole on the bottom that you need to plug too.

 

[werty1188]

Re: Aq125 issues

ok so turns out the prop wasnt the issue. after i put a new prop on i took it out and it still felt like it was sliping. so i rebuilt the carb put a new fuel pump on, new impeller, the thermostat was sticking so i fixed that, new spark plugs, converted it to electronic ignition,new coil, took apart and cleaned the heat exchanger, intsalled a water fuel seporater,drained out the old gas and put new gas in with some sta-bil, and ajusted the timing. I took it out yesterday and the sliping issue seems to be fixed. It seems to run fine untill it hits 38000-4000 RPMs then is boggs down and kinda acts like its not getting enough fuel. Any idea on why it would still be acting that way? Thanks again!