How to change the oil on a 305 Mercruiser

[Dreamer1Q]

I cant believe I am asking this question, but boy are boats different then my racecars. Is there a special way to do this, or is it just pull the plug and hope you get it all in a pan. I feel like I am in 1st grade again

 

[Haut Medoc]

Re: How to change the oil on a 305 Mercruiser

Buy an oil pump at west marine & suck it out of the dipstick tube, make sure you run it till the oil is warm.....JK

 

[MRS]

Re: How to change the oil on a 305 Mercruiser

Buy oil drain hose kit that way you can run hose out drain plug hole and it makes life awhole lot cleaner.

 

[vipzach]

Re: How to change the oil on a 305 Mercruiser

Most boats don't have enough room under the engine(s) to get an oil pan under them, that is why you can buy a pump and pump it out the dipstick tube. They make them electric or manuel. They also make kits you can get to allow you to drain it from the drain plug. Like JK said though, run it fir a while an get the oil warm, it makes it much easier to pump out.

 

[KM2]

Re: How to change the oil on a 305 Mercruiser

I like the manual pump from Tempo. I think I boats sells it too.

 

[KaGee]

Re: How to change the oil on a 305 Mercruiser

Yes, go the pump route. Those who opt to drain via a hose out the bilge hole complain that it takes f-o-r-e-v-e-r to drain the oil. Plus, depending on your boat, getting to the pan to install the drain hose can be a real biatch.<br /><br />If the outside temp drops below 60, then warm up the engine prior. You going to leave a little oil, not much, whether cold or warm.

 

[NYMINUTE]

Re: How to change the oil on a 305 Mercruiser

The drain hose works well if the oil is warm. Takes a bit of time, which is a good time to perform other maintenence like cables, fuel filter etc.

 

[Bondo]

Re: How to change the oil on a 305 Mercruiser

It took a couple of oil changes,......<br />But,......<br />I figured out the BEST way,................. <br /><br />I rigged my pump to the end of the bilge-hole oil drain line,..........<br />Fast oil changes on the trailer,........ Or with My Extended Hose,.... At the Dock Too.........<br />And,..... All the oil comes out,.....<br />I Never did like the idea of sucking it thru the dipstick tube................ <br /><br />Another tid-bit,............<br />After you Crack the filter Loose,......<br />Use a Zip-Lock Baggie around the Oil Filter(or gas filter) to catch the Drippings,.......<br />Spin it Off,... Drop it In,.... Seal it Up....................

 

[f_inscreenname]

Re: How to change the oil on a 305 Mercruiser

Put a heavy duty trash bag under the motor and pull the plug. Sucking the oil out the dip stick just sucks.

 

[hoot]

Re: How to change the oil on a 305 Mercruiser

used the trash bag trick some, doubled mine up. gotta be darn careful pulling the bag out. one rip thru both bags and one freaking mess!!!

 

[Manipulator]

Re: How to change the oil on a 305 Mercruiser

If you pump the oil out via the dipstick, is there usually a quart left in the pan that you can't get out? Seems that way with my boat. How can that be?

 

[vipzach]

Re: How to change the oil on a 305 Mercruiser

You shouldn't have a quart left. When I pump mine out, there is very little left in the pan. I have pulled the plug before, just to see what is left. Did you have the filter and fill cap on?

 

[Manipulator]

Re: How to change the oil on a 305 Mercruiser

I had the filter on. I usually take that off after the oil isout of the motor. My filter has been relocated and is not attached to the engine. Looks like the guy who had the boat before me did this. It has rather large rubber lines to and from the filter. I'm sure oil remains in the line due to the way the relocation kit is mounted but not a quart.<br /><br />Tell me this, does the diptick tube lie below the pan to make sure all the oil gets out? I mean, if it ran right into the block, it would not be able to go all the way to the bottom as the dipstick would hit the pan. If that make any sense.

 

[Bondo]

Re: How to change the oil on a 305 Mercruiser

Tell me this, does the diptick tube lie below the pan to make sure all the oil gets out? I mean, if it ran right into the block, it would not be able to go all the way to the bottom as the dipstick would hit the pan. If that make any sense.

Automotive Dipstick Tubes are pressed into a hole in the Block,... And end there.........<br /><br />Marine Oil Pans,... The hole in the Block in covered by the flange,+ the Dipstick Tube is mounted Thru the wall of the pan,+ Ends Just Short of the Bottom,.... Maybe a 1/4".......Probably Less.....<br />Others,.. the Dipstick Tube runs down the side of the pan,+ is connected by a fitting in the drainhole.........<br />And,.... I'm Sure there's Other designs,.... But Most All the 1s I've run accross have Me thinking there's Always too much oil left,....<br />That's why I've got the Drain Tube.........

 

[trebor0301]

Re: How to change the oil on a 305 Mercruiser

Everybody has there own "BEST" way of doing it.Here's my NOT WHAT TO DO... Dont slide an oil pan under your motor and start draining.Yes you can probably get one under the motor but try getting the pan full of oil back out I'm just glad my buddy's weren't with me!!

 

[Dreamer1Q]

Re: How to change the oil on a 305 Mercruiser

Thanks for all the answers guys. I appreicate the help!