Compression on Volvo L6

[jstange2]

I am looking at buying a boat that has a Volvo BB170 Inline 6 cylinder. I am going to test the compression right now in the cylinders. It usually idles fine but it will not idle after acceleration. I can accelerate around the lake for 20 minutes fine but as soon as I pull back on the throttle it will die. There seems to be some gas smell from the oil. Is there anything else this could be? I just thought I would start with compression.

 

[Robj]

Re: Compression on Volvo L6

Regardless of how well it does or does not run. Run away from this boat. Those engines are old, parts are difficult to find and if you find them, they are expensive. Look for a water pump on ebay, $932. Who knows how much an exhaust manifold is. Keep looking for something that is more common and recent. It will cost you much less in the long run.

Have a great day

Rob.

 

[captmello]

Re: Compression on Volvo L6

i agree with Robj, those motors are rare and expensive. The exhaust manifold is still available from Vovlo however. $2700.00.

Is it really a BB170 inboard or an AQ170 I/O? Just curious.

Either way, look for something else if you haven't already bought this one.

 

[jstange2]

Re: Compression on Volvo L6

Well, looks like you were right. It is a AQ170. The compression is between 136 and 150 with #1 at 164 for some reason. I did end up buying it because the guy is a buddy of mine and said he just wanted it gone for $500. I hope to get out with it tonight to see if the new spark plugs helped at all (4 were one brand and number, 1 was another brand and number, and the 6th was another entirely and 3/8ths of an inch longer.
Now all I have to do is figure out the trim tilt so I don't have to strap the lower unit up while backing into the lake. It clicks, but I don't even know if the wires on the switch are hooked up right. They were all three loose when I had the dash out. Anyway, hopefully I didn't get too big of a lemon.

 

[captmello]

Re: Compression on Volvo L6

Let us know if you need help. We'll do what we can. Those compression numbers sound ok, according to the manual those engine should have between 170 and 200 psi, which is quite high.

It doesn't sound like its been well cared for and I would recommend either going through it yourself, or having a mechanic go over it before you start putting much money into it.

If you choose to do it yourself and are mechanically inclined, we will help you along the best we can. Maybe Don S will give you a link to a manual for your engine and drive.

Check out this link as well. Type in aq170 in the 'engine type' box and hit enter. There is more info to be had there.

http://www.volvo.com/volvopenta/global/en-gb/marine_leisure_engines/parts_service/publication_search/publication_search.htm

Good luck!

 

[jstange2]

Re: Compression on Volvo L6

Thank you captmello! I can do quite a bit mechanically, and for the things that I can't, my buddy can fix literally anything. The spark plugs somehow smoothed out the motor and out of 7 or 8 hard runs and throttling back, it only died once, but that may be from the hard run for 12 or so minutes.
Thank again for the information. I found the manual for the engine now I need the one for the drive.