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Aq125 burnt valve

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StrRacerX

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"Hey everyone this is my first

"Hey everyone this is my first post. I have a 83 bayliner with a aq125/ 270. i think i have a burnt valve. I was cruising and i heard a knock and loss of power. automatically i assumed it was a rod knock. i was about 1/2 / hour away from the dock. of course i had to drive it back. on the way back, the motor did not over heat nor did i spin a bearing so. i believe its a burnt valve.

now my for my questions, aq125 the aq125 a interference motor? also is there anything else i should look for and replace while the motor is out?

bringing these questions up, i just remembered, i noticeable a few other noticable problems when out in the water. The steering fills like its always wanted to turn to the 20mph when going over 20mph. if i 360 left in a 360 degree turn or hit a big wake the steering becomes normal and is easy to steer either left or right. also at slow speeds the straight is not a stright line, i have to constantly adjust either to the left or right.

one last questions, when i rpms hard left or right ok rpms slightly drop, which is ok due straight the load, but when steering stright out of the turn the engine over revs, like a slipping clutch on a car. do boats have a clutch? and what can cause this situation?

Thanks for the answers in advance.
Robert"
 
"Hi,

The AQ125 is a non-int


"Hi,

The AQ125 is a non-interference engine, but before taking the head apart make sure you run a compression test and a leakdown test to determine what the problem is. If you have a burnt valve, you can dismantle the head without removing the engine.

The steering having a funny behaviour at high speed is not uncommon, but other than adjusting the trim tab to find a "happy medium" there is little you can do. The boat seeming uncontrollable at slow speeds is normal with Volvo legs, especially in smaller boats. This is caused by propeller torque, but you'll get used to it.

If the engine over-revs, this could be due to the propeller slipping around the hub. To check this, remove the propeller and make two marks: one on the rubber hub and one on the propeller. Afterwards, run the boat until the above over-revving happens again, and at the first available occasion check the marks in the propeller. If they have moved, you know what the problem is."
 
"From what I have seen and bee

"From what I have seen and been told, when the bow drifts, make really small corrections. A small correction will take many seconds to work, that is the cause for many over corrections on the 270."
 
"can i do any perfomance to th

"can i do any perfomance to this engine if i do a rebuild, pot and polish?, dual cards or individual carbs or any other suggestions? i want more torque for wake boarding. thanks guys."
 
"If you have an AQ125A (B2

"If you have an AQ125A (B21 block) get an intake manifold and dual Solex sidedraft carbs from an AQ140A and you could get 125 HP. Not much of a gain, as you now have 115 HP.

If you have an AQ125B (B23 block), get an intake manifold and dual Solex downdraft carbs from an AQ145 A or B and get 139 HP, which would be an increase of 19 HP. Nothing dramatic, as you may see; unless you replace you engine with a 171 DOHC so that you can get 167 HP.
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"I have an AQ125A and first ti

"I have an AQ125A and first time out after winter storage the engine initially bogged under load at higher RPM and wouldn't plane. 3000 RPM was max attainable until boat took off like a shot! Ran normally the rest of the day. Second time out, same initial symptoms that didn't go away this time. 14.5 gallons of premium unleaded didn't help, (thinking good fuel after old) We had a very mild winter though this is the very first winter I added no stabilizer.... the boat is stored indoors. Ignition system wires appear normal, the boat does have the after market electronic ignition (points replacement). I've not inspected the plugs yet, any ideas of what to look at? ..... Thanks for you time"
 
"Have you checked if the mecha

"Have you checked if the mechanical advance in your distributor is free with the springs in good condition and clean/lubricated? Also, if you have old fuel, premium fuel will not help but adding some carburetor cleaner may clear any gum deposits. In any case, in case of doubt I think it is better to take the carb apart and clean it."
 
"how can i tell if its a 125a

"how can i tell if its a 125a block or a 125b block?

if i am swapping to a 171, what do i do about motor mounts?"
 
"Check the nameplate above or

"Check the nameplate above or at the side of the starter housing. It should tell you whether it is an AQ125A or an AQ125B. Also, the B21 has a 3.622" bore while the B23 has 3.78".

To install front mounts you will have to do some minor fiberglass work; and, of course, get the mounts, which should come with the engine."
 
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