Help id’ing part thats smoking. 1986 aq151a

[NorinRadd]

Bought a 1986 17.5 double eagle with an original aq151a. A part I cant id has a breather tube that has a bit of smoke and blow by when im in high rpm. No smoke or blow by at low speeds.

Also been struggling to find a basic parts diagram of the outer engine. So many things I dont know what im looking at. Can anyone provide one?

Part with hose is roundish. Attached to block on portside. Will add photo. Prt is circled in yellow. Hose has green line.

Please and thanks

 

[NorinRadd]

Picture

 

[Fun Times]

You mentioned tube, is it rubber or metal?

Sort of hard to tell in the photo but In generally looking around had me wondering if it’s item number 16,

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Or 36, https://www.volvopentastore.com/Cyl...on_id.885085722--store_id.366--view_id.777186

Either way, here’s all your 151A engine parts to search around in, https://www.volvopentastore.com/Mar...Q151C-7744660/dm/store_id.366--view_id.765178

 

[NorinRadd]

You mentioned tube, is it rubber or metal?

Sort of hard to tell in the photo but In generally looking around had me wondering if it’s item number 16,

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Since 1998, iboats is the most trusted water lifestyle online store for boat parts and accessories, boats for sale, and forums. Enjoy great priced products with fast shipping.

www.volvopentastore.com

Or 36, https://www.volvopentastore.com/Cyl...on_id.885085722--store_id.366--view_id.777186

Either way, here’s all your 151A engine parts to search around in, https://www.volvopentastore.com/Mar...Q151C-7744660/dm/store_id.366--view_id.765178

I had seen both of those diagrams. One is at the back of the block and the oil pump is at the bottom inside the oil pan. Its crazy there isnt a basic photo of this motor like from factory. With basic parts diagram. You know, pointing out basic parts. Impeller, fuel pump, water pump, carbs. The basic stuff. Most is self explanatory but this thing. I have no idea. I cant get a good photo of it. Cant find it on parts diagrams on those parts sites.

 

[NorinRadd]

Hard to get a good photo

 

[Fun Times]

Seems the hose vents down to nothing?

Volvo AQ151 Motor

Repowering my boat, Running Volvo Penta AQ 151B ,Has bronze intake and exhaust manifolds and new distributer . 900 hr on new Head 2100 on Motor. Will be parting out on Ebay if no takers at $750.00. Comes with lots of spares water pumps etc. call...

www.bdoutdoors.com

Volvo Penta 230 Workshop Manual (Page 37 of 102) | ManualsLib

www.manualslib.com

 

[kenny nunez]

That hose is the crankcase vent that is supposed to be plugged in to the air intake box. There should be a nipple or a hole where the hose fits.

 

[NorinRadd]

That hose is the crankcase vent that is supposed to be plugged in to the air intake box. There should be a nipple or a hole where the hose fits.

The air intake box? as in the muffler for the spark arrestors that look like air intakes? Are they also air intakes?

Crankcase vent also is okay to smoke?!

 

[ESGWheel]

Crankcase vent also is okay to smoke?!

Short answer, yes.
Longer answer: is it too much? If a LOT it may be an issue.

These engines, by their very design, have what are called ‘blow by gasses’. These are small amounts of combustion gases that makes it by the piston rings. If this is not vented off, pressure will build inside the crankcase and start causing seal and gaskets to leak. The blow-by gases are typically routed back to the intake of the engine to ‘burn off’. Back decades ago, in cars, the venting was simply a tube pointed to the road. But as time goes on, they got more sophisticated. You my have heard the term “Positive Crankcase Ventilation” or of the “PVC” valve > these are the same thing > bring these blow-by gasses back to the intake. So yes, the hose goes up to and gets positioned next to the spark arrestor which is the engine’s intake. Here is an article (link) on crankcase ventilation that may help.

A LOT of blow-by gasses is indictive of a worn engine, e.g., the piston rings are not doing their job. A good health check for the engine is to do a compression test. It’s the rings that ‘hold’ the compression.

 

[ESGWheel]

Here is a picture of what the spark arrestor looks like for my VP engine. Not sure of your configuration but this is the idea. Perhaps the hose bib has gone missing on your spark arrestor and thus why its pointed into the bilge?

 

[Fun Times]

^ Nice kenny nunez and ESGWheel.

14 into 8 from 36/31, https://www.volvopentastore.com/Fuel-System-A/dm/store_id.366--view_id.777318

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Since 1998, iboats is the most trusted water lifestyle online store for boat parts and accessories, boats for sale, and forums. Enjoy great priced products with fast shipping.

www.volvopentastore.com

Volvo Penta AQ171A Dual Carb Cover # 841701 | eBay

Used and working cover.

www.ebay.com

You can see the nipple here,

 

[ESGWheel]

NorinRadd,
So, I think this is now solved. But as a recommendation: take the device apart (apparently, it’s called a muffler) and thoroughly clean it. I assume there are some sort of metallic spark arrestors inside as well that can be removed. A bucket of warm soapy water (Simple Green works well) and let them soak for a while agitating them occasionally. Thoroughly rinse. Repeat if needed. Reassemble and good to go. Note that cleaning it should be an annual PM.

 

[NorinRadd]

That hose is the crankcase vent that is supposed to be plugged in to the air intake box. There should be a nipple or a hole where the hose fits.

Amazing thank you

 

[NorinRadd]

Short answer, yes.
Longer answer: is it too much? If a LOT it may be an issue.

These engines, by their very design, have what are called ‘blow by gasses’. These are small amounts of combustion gases that makes it by the piston rings. If this is not vented off, pressure will build inside the crankcase and start causing seal and gaskets to leak. The blow-by gases are typically routed back to the intake of the engine to ‘burn off’. Back decades ago, in cars, the venting was simply a tube pointed to the road. But as time goes on, they got more sophisticated. You my have heard the term “Positive Crankcase Ventilation” or of the “PVC” valve > these are the same thing > bring these blow-by gasses back to the intake. So yes, the hose goes up to and gets positioned next to the spark arrestor which is the engine’s intake. Here is an article (link) on crankcase ventilation that may help.

A LOT of blow-by gasses is indictive of a worn engine, e.g., the piston rings are not doing their job. A good health check for the engine is to do a compression test. It’s the rings that ‘hold’ the compression.

Thank you!!! Yes I have replaced pcv many times. I figured it was some sort of breather. Was debating pitting a filter on the end of it like the old valve cover breathers. I do get some blow by. But I believe it was exaggerated from the hose pointing straight down. Smoke was very minimal and like I said. Only at wide open throttle.

 

[NorinRadd]

Here is a picture of what the spark arrestor looks like for my VP engine. Not sure of your configuration but this is the idea. Perhaps the hose bib has gone missing on your spark arrestor and thus why its pointed into the bilge?

Too bad these damn flame arrestors are $1000. So outrageous.

 

[NorinRadd]

NorinRadd,
So, I think this is now solved. But as a recommendation: take the device apart (apparently, it’s called a muffler) and thoroughly clean it. I assume there are some sort of metallic spark arrestors inside as well that can be removed. A bucket of warm soapy water (Simple Green works well) and let them soak for a while agitating them occasionally. Thoroughly rinse. Repeat if needed. Reassemble and good to go. Note that cleaning it should be an annual PM.

Mine are very dirty. Planned on cleaning. Thank you. One is coming undone. But the cheapest I can find them is $700 usd. Which is crazy. Ill replace the motor before soending $1000 cad on some wound brass

 

[NorinRadd]

^ Nice kenny nunez and ESGWheel.

14 into 8 from 36/31, https://www.volvopentastore.com/Fuel-System-A/dm/store_id.366--view_id.777318

All Products | iBoats

Since 1998, iboats is the most trusted water lifestyle online store for boat parts and accessories, boats for sale, and forums. Enjoy great priced products with fast shipping.

www.volvopentastore.com

Volvo Penta AQ171A Dual Carb Cover # 841701 | eBay

Used and working cover.

www.ebay.com

You can see the nipple here,
View attachment 388241

Thank you! Didnt notice the nipple ill go check this evening