Well Another headscratcher for Yall to contemplate

[Tom_Cody]

1985 Volvo/Penta AQ125B 270 outdrive 4 cyl closed cooling system. I have been running the boat the past few seasons, with no problems. I have upgraded to electronic ignition, the boat starts and runs(ran) excellent. Drove back to the dock the other night, went back to boat next afternoon to take a cruise. It Started and I stalled it as I was backing away. It would not refire, Got it to Put once. So I removed the doghouse and had the engine turned over while I looked at it. It didnt sound right, and to my horror water was coming out of the carb/spark arrestor. It was sea water not coolant. So i kinda ruled out a cracked head. (coolant level full) Also to add to this dilemma, there is no compression. (most I got was almost 25 psi outta #4 they were all around 130 just last spring.) So now Im thinkin cracked or bent valves or broken camshaft or possibly head gasket but there is no water in the oil. All this still dont explain the water coming outta the carb. I have the exh man removed, checkin for cracks. Nothing noteworthy here. I just removed the intake and valve cover, cam is ok. I guess next is Head removal. Anyone heard of anything like this? Need good source for gaskets as well.

 

[denniz]

Re: Well Another headscratcher for Yall to contemplate

Has to be coming in thru the exhaust. Is the flapper missing off your outdrive (some had in the bellows?) Backing up, stalled, water in cyl. Doesnt account for the loss of compression though unless you bent some valves or push rods. Id pull the head.

 

[denniz]

Re: Well Another headscratcher for Yall to contemplate

AQ125's dont have push rods you MORON( I slapped Myself)

 

[akriverrat]

Re: Well Another headscratcher for Yall to contemplate

while you are taking head off pause a moment when cam belt comes into veiw and check alignment. belt slipping could cause low and equeal compression. maybe.

 

[ODDD1]

Re: Well Another headscratcher for Yall to contemplate

Yeah, first thing i would look at too....to keep air moving in the right direction thru a motor you need proper cam/valve timing....how many teeth missing on that belt?

 

[Tom_Cody]

Re: Well Another headscratcher for Yall to contemplate

Well well Seems that the automatic tentioner isnt so automatic anymore, and it doesnt turn so well either. The timing belt teeth are almost nonexistant. Hence the no compression, valve timing outta whack. Which was kinda lucky as it didnt try and compress the water it sucked in, it just blew it outta the intake valves. Been back at work havent had much time to work on the old boat. Will keep ya posted, thanks for the suggestions as well.

 

[akriverrat]

Re: Well Another headscratcher for Yall to contemplate

that is the real problem with this engine. the tensioner is not automatic. every X number of hours you are supposed to loosen the clamp nut, let the spring adjust tension and retighten clamp. if you don't follow vp's schedule you will jump timing.