My first oil change was also a big mess. Then I leaned the best way to do this. I have M35B - I am not sure if yours has a drain plug at the bottom of the pan - but that is what I use to drain the oil. For $ 34.00 I purchased a pump with 12VDC motor from Harbour Freights [url]http://www.harborfreight.com/catalogsearch/result?q=12VDC+pump[/url]
Part Number Item #94639
I place a 1 quart yogurt container under the drain plug and let the oil drain into the container while I pump the oil out. The Pump will remove the oil faster than it will come out of the drain. After it has completed reinstall the drain plug. The instruction in the manual is incorrect for the 5QRT. The correct amount is 3.5QRT. Before draining - if you run the engine for 3 minutes - it will drain faster. If you make the oil much hotter it will burn your fingers.

Capt Sam

I have the same engine and most always make a mess. I have a two gallon metal vacuum can with a thin plastic hose that goes into the oil dip stick. This has not worked well. I have also tried a hand held pump which worked with a lot of effort and a mess. A friend of mine had a tall white plastic vacuum container used with a tube in the dip stick that worked well with great suction. I am going to find where he got it. One trick is to get the oil hot-not burning hot-it flows much easier. I found over the years that my boat holds exactly 4 quarts with a new filter. There may be a little left, but not much.

I bit the bullet and paid $50 for the west marine vacuum oil changer -- it's now gone up in price since last season, and I bought it on sale, so I think now it is closer to $100 ([url]http://www.westmarine.com/oil-change-pumps/west-marine--manual-oil-extra...). Amazon sells the same thing for under $50, with Prime to boot: [url]http://www.amazon.com/America-5060-Topsider-Multi-Purpose-Removing/dp/B0...

They both come with small hoses that you just stuff into the oil pan drain or the dipstick up. Works brilliantly and is extremely clean; never more than a few drops of oil. The vacuum extractors are way simpler / cheaper than the electric variety.

My oil / filter changes are nearly dripless; I use a ziplock when changing the filter and it works pretty well.

Just a note:
The deep part of the oil-pan is at the front and by using the drain tube you can remove most of the oil in that section, but not all. If you also look you will see that the rear of the engine slopes back and some oil is going to accumulate there as well so you will want to go through the dipstick to try to get to the back (lowest point).
I have used the 2 gal vacuum can for about 30 years and if careful it does a decent job with little mess. I never liked the fact that when changing the oil it turns black pretty fast because of the oil you can't remove but the Catalina 30 I had is still running and there has not been a problem related to the oil.

I agree with David and Gary. I also purchased a vacuum oil changer and have found this the easiest and cleanest way to drain the oil. Simply stick the tube down the oil drain hose of an M25, a few strokes on the handle and in 5 minutes with warm oil (or 20 minutes if cold) the job is done. Nary a drip to clean up!

I too use a West Marine pump and highly recommend it though I find the pickup hose is so small that if the oil isn't hot it wont flow.

I carry mine on the boat at all times... first because I once had an overheating problem and had to change the oil after resolving that issue but also when I change fuel filters after I take them off the 1st thing I do ids use the pump to drain them so I don't drip any fuel trying to pour it out of the filters. I also had some oil in the bilge once and used the pump to extract the oil off the top of the water in the bottom of the bilge.

One tip if you get the kit with the pump on top of the 3 gal bucket.... its very top heavy. I keep the pump in its original box (always) then I put that box in a larger box in which I had purchased 6 gals of winter anti freeze. Fits perfectly and the extra space in the larger box gives me room to store a sheet (which I put under the whole unit when using) as well as a one gal gas container (painted yellow) which I fill with diesel when I'm changing filters. This allows me to easily fill the filters before installing them on the engine and having to bleed the whole system.

With the vacuum pump, I find that the hose will jam in the curve at the bottom of the dipstick tube and you won't get much out. Take the insert out so you are working in the big hole not the dipstick hole and carefully roll the hose while you apply light down pressure, it will go down into the sump and you'll get more oil. But you'll still leave way too much IMHO.

The sump is a terrible design for a boat engine mounted on a steep incline, you do leave a lot of filthy oil in there. I've said it before but it amazes me that they would do such a stupid thing as having the drain at the top end of the pan. Just ridiculous and it shows a serious lack of attention, or care, by Westerbeke. One would think for the price of these motors they could have put a new plug into the back of the pan.

I have some minor leaks around the pan gasket, when it becomes bad enough to change the gasket I'm taking the pan to a metal shop and have them braze a new drain plug in the low end where it should already be.

Nothing bugs me more than seeing filthy black oil immediately after changing it. People try to justify it, it's just carbon black don't worry about they tell me. BS to that, my Kubota tractor oil has always been gold coloured when I change it because I get every drop out.

If I ever have to pull the pan I'm going to put a fitting(s) so that I can have a permanently mounted oil change pump on the side of the engine. I had this set up on a Beta 25. I really miss it. I also have seen this on a perkins 4-108. It took less than 5 minutes to change the oil.

I feel fortunate that the PO installed a 12V oil pump out on my M35. I have checked the price online and it runs about $120. It has a metal pick up tube that runs down to the very bottom of the oil pan and picks up most of the old oil. I think it will be money well spent to have one onboard.

i USE A SMALL PLASTIC CONTAINER THAT WILL FIT UNDER THE ENGINE AND DRAIN OIL FROM THE OIL DRAIN ATTACHED TO THE REAR OF THE ENGINE. WHEN THE CONTAINER IS FULL I REPLACE THE PLASTIC LID, WHICH SEALS, AND REMOVE IT FROM UNDER THE ENGINE AND DRAIN IT INTO A GAL MILK BOTTLE. iT TAKES ABOUT THREE FILLS OF THE PLASTIC CONTAINER TO COMPLETE THE JOB.
RAY KALINSKY LITTLE MISS MAGIC

The 5 qt figure is incorrect. My manual said that too, but was corrected to 4 qt in a later version. 4 qt is the correct amount for the 35BC engine. You will never get all of that amount extracted, though. Like others have mentioned, the engine is tilted and the drain or the dipstick may not be at the deepest place. The tilt is not too bad though, and the remaining oil should not be very much. Don't forget that there is oil in the filter you remove. I usually get around 3.5 or more qt out of the engine including what is in the filter. Don't forget to extract the oil from a warm engine rather than cold. I run it at dock for maybe half an hour before the change. Warm, but not hot. To get that last bit I alternate between the hose from the bottom of the pan and the dipstick.

I don't find too much of a mess except for getting the filter off. For that I use lots of paper towels under it and try to remove it fast.

When filling with clean oil, don't forget to also check the level after running it for a little while. That will get the oil back into the filter and lines for an accurate level.

When I take the oil filter off I put one of my multi-purpose Pampers under it and hold it there as I unscrew it. Use the Toddler or bigger size, the Newborn size is kind of touch and go for holding all the oil that is likely going to come out.

Check out on line a Mityvac 7400 7.3 liter oil extractor. That might be the answer. Has anyone used one? They are $66 at Amazon. West Marine has a similiar looking one for $96.

Got one from Amazon last summer and have used it twice. Works great with warm oil. Removed ~4 qts from my M35A.

Edit my respoinse to say I get out 3.5 qts. or a little more PLUS what is in the filter so it is pretty close to 4 qt. total.