AQ125a overheating

Joined
Jul 30, 2024
Messages
6
Well to start with is in 1983 Bayliner cuddy 1950 ,bought the boat ,was lied to , the old boat sat for some years , but " we " me and the boat have come an agreement , that she will only present me with one problem at a time , started out with no fire , cleaned the points and reset , fixed.
then bad gas , pumped that out with electric fuel pump , 12.5 gallons later , next bad fuel pump , fixed with new one from US boat works Kansas City Kansas . , then not cooling replaced impeller still not cooling under power only with ears and a hose . So I decided to run it on the water to 200 crack the cap ,airlock. Starts cooling at an idle , so run it some more on ears at home stays cool raised roms. Some trash blows out the exhaust , so then back to the lake last Friday for an overnighter ,what the heck , got warm about 190 and hung out there a bit , so Saturday kids want to tube , won't get up on plane , won't go over 2000 rpm , so took it home .
Sunday kids are cool with the speed so we take her again , stays under 180 runs cool stays cool , so my advice for guys with boats that have set , be patient good things come for those who will let an old boat come to life , so now rpm issue , whike on water had a bush fix used a business card to set the points ,tada 3000 rpm and climbing , oh yeah put two kids on the bow to get the nose down and shes on plane and we are cooking with gas , now to my question
This crazy thing has what looks like a kickstand , I'm assuming I have to take that out inorder for the locking mech to work . And because the boat appears to be light in the nose should I set the lower unit to lock in the most forward position possible ??
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
49,540
Anything over 150 is an overheat

Start with servicing everything...... That the PO didn't

Pull the drive, for all drive maintenance, including a new water inlet casting (common issue)

Pressure test the O-rings at bottom of pivot tube

Service the raw water impeller again (it's probably toast)

Use a dwell meter to set the points. Then set timing

Service all fluids and filters
 
Joined
Jul 30, 2024
Messages
6
Yeah let's just stand back and throw money at it and change parts that have already been changed ,and take stuff apart that has no issue . Makes since , I don't of you are aware but these old parts are expensive .
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
49,540
Boating is the world's most expensive hobby

However with any new to you boat, you need to do all the maintenance that was ignored by the prior owner before selling it to you. I simply listed the annual maintenance requirements for your AQ series drive. Most likely a 270

The raw water inlet fitting lasts about 1.5-2 years in salt water and about 3-5 years in fresh water. It's about $18 for the kit, (fitting and gasket)

The O-ring at the bottom of the pivot tube is another known issue for water flow. Requires the drive to be split to replace

Since you are most likely loosing water flow as you come up on plane, that is the prime candidate. Running without water flow will have burned up your new impeller.
 

kenny nunez

Captain
Joined
Jun 20, 2017
Messages
3,290
The kick stand you referred to is the trailering bracket. It has to be removed for boating. The way the Volvo trailering/beaching lift is made the pitch of the lift screw will not hold the drive up when trailering and the drive could be dragging on the ground.
 
Joined
Jul 30, 2024
Messages
6
Boating is the world's most expensive hobby

However with any new to you boat, you need to do all the maintenance that was ignored by the prior owner before selling it to you. I simply listed the annual maintenance requirements for your AQ series drive. Most likely a 270

The raw water inlet fitting lasts about 1.5-2 years in salt water and about 3-5 years in fresh water. It's about $18 for the kit, (fitting and gasket)

The O-ring at the bottom of the pivot tube is another known issue for water flow. Requires the drive to be split to replace

Since you are most likely loosing water flow as you come up on plane, that is the prime candidate. Running without water flow will have burned up your new impeller.
Thank you the impeller is pumping , pretty sure it was a blockage in the exhaust manifold , that cleared , us boat works told me that these come with up to four different thermostats from 165 to 190. So if yours is running at 150 ? Cool plus I'm running in 90° water in power plant cooling lake
 
Joined
Jul 30, 2024
Messages
6
The kick stand you referred to is the trailering bracket. It has to be removed for boating. The way the Volvo trailering/beaching lift is made the pitch of the lift screw will not hold the drive up when trailering and the drive could be dragging on the ground.
Thanks , what about moving the lock pin forward to bring the nose down
 

kenny nunez

Captain
Joined
Jun 20, 2017
Messages
3,290
Just try it in different settings. Most times the center hole is the best all around. Is your transom flexing? Bayliners have a bad reputation with transom problems. Look inside where the bolts come through, check to see if the hex nuts are tight.
 

captmello

Captain
Joined
Jun 30, 2008
Messages
3,845
the aq125 is supposed to run at 180-190 deg, it has closed cooling. set the points with a dwell meter, then readjust the ignition timing every time you adjust the points. you also may want to try a prop with less pitch to help get up on plane.
 
Joined
Jul 30, 2024
Messages
6
Just try it in different settings. Most times the center hole is the best all around. Is your transom flexing? Bayliners have a bad reputation with transom problems. Look inside where the bolts come through, check to see if the hex nuts are tight.
Thanks will try
 
Joined
Jul 30, 2024
Messages
6
the aq125 is supposed to run at 180-190 deg, it has closed cooling. set the points with a dwell meter, then readjust the ignition timing every time you adjust the points. you also may want to try a prop with less pitch to help get up on plane.
Thanks
 
Top