How much should an engine compression test cost?

JonO

I've read enough to know that a compression test is one way to judge the current performance of an outboard motor... how much should that cost?

Beyond that, and a sea trial, what other checks should normally be done? Evaluating the oil in the upper and lower for water or other contamination? And what's a reasonable cost for that?

TIA...

JonO.

Barry Rietz · Posted: Wed Jun 30, 2021 11:47 pm Post subject: Engine Condition

Jon, Depending on the number of hours showing on the meter, you might also want to do a "cylinder leakage" test while assessing the "condition" of the motor. You also need to consider the age of boat and whether the original motor was replaced at some subsequent date. Have the seller provide a detailed history along with manuals and receipts that should be part of the "ships log".

hardee · Posted: Wed Jun 30, 2021 11:47 pm Post subject:

Where I am, a commercial marine mechanic shop is going to charge by the hour, probably a minimum of one hour. Shop times are somewhere between $90 and $140 an hour. My certified Yamaha Mechanic shop is $120 and they do good work, don't try to sell me stuff I don't need, and let me know if I have something that needs to be addressed. I trust them and after 15 years I still highly recommend them.

Harvey
SleepyC Moon

JonO

Thanks for the replies. Seller says motor is a 2018 Honda 150 with 104 fresh water hours. No maintenance records are available. How would these points affect your decision on evaluating the condition of the motor?

JonO

bshillam · Posted: Thu Jul 01, 2021 9:54 am Post subject:

That new a motor should be fine but it's an expensive motor to address if it has major defects. Get a compression test, have it hooked up to a computer check to make sure it hasn't had any alarms, Have a survey and check for high moisture/separation/delamination.

JonO · Posted: Thu Jul 01, 2021 9:59 am Post subject:

Thanks, bshillam

This is on a 23 Venture, so my understanding is there is no balsa core. Wondering if moisture measurement, etc., still applies?

bshillam · Posted: Thu Jul 01, 2021 10:51 am Post subject:

No balsa that's ok, but you still want to know if a fitting has allowed water intrusion. If you go through a freeze/thaw cycle with water it could start to do some damage to the layup.

T.R. Bauer · Posted: Thu Jul 01, 2021 11:42 am Post subject:

You don't water in any cored boat. What's in their may not technically "rot", but it's not a good situation. As far as the Honda....a good hard sea trail would probably be telling about the condition of the motor and I suspect it's fine. But, if you're not doing one, a compression test will likely verify what the hour meter shows - a basically new engine.

thataway · Posted: Thu Jul 01, 2021 5:55 pm Post subject:

For the new a motor (no know issues on the 2018 Honda 150's) I would just do a sea trial. Run the motor from Idle to WOT and see what the RPM (should be 6,000) and speed (over 30 knots). If you get these, and the motor cosmetically looks good does not overheat--pees well--then go for it.

About the core--just because a boat has a foam core, does not make it immune from core issues. Many even new foam core boats can have problems. Definitely if water intrudes as T.R Bauer notes--impacts, poor lay up bad adhesion of layers. Even brand new boats can have issues. I read about a lot of them.

C Dory has had some in the distant past--none known now!!!

JonO · Posted: Thu Jul 01, 2021 5:59 pm Post subject:

Thanks. The Venture is also 2018... can't wait to do a sea trial.

JonO

Barry Rietz · Posted: Thu Jul 01, 2021 11:03 pm Post subject: Prepurchase Assessment

Jon, "Colby Smith", who is a very knowledgable, experienced, and active C-brat lives in Madison, WI. He is retired and most likely would provide answers to the many questions you have yet to ask. Send him a note to see if he has the time to assist with the evaluation. I'm down near Janesville and available if Colby is out cruising North America for the summer!

colbysmith · Posted: Sat Jul 03, 2021 12:01 am Post subject:

I Connected with Jon on FaceBook. And I am doing a lot of traveling. Isle Royale in a few days, and then Les Cheneaux Islands in August. Smile

I also suggested he talk 23's with James Wildmann. Thinking with only barely over 100 hours on the outboard, I suspect the only maintenance that may have been done would be an engine oil and lower unit oil change. At least those should have been done annually. I agree with others about a sea trial and see how it runs. I believe the boat is in another location, so it might be worthwhile to have a surveyor look at it. Also, has the boat been kept in the water or on a lift or on the trailer? 2018 would be fairly new, so I would think chances are pretty good if it wasn't used much, and not kept on the water, probably no water issues, yet. Also the boat is consigned through a dealer and perhaps they can offer a bit more of a warranty.

Actually, I just did some googling here. Jon, you might want to do some more research in the archives here. This boat does have a photo album. Going thru this album, I'd question the part about fresh water hours, as some of the photos show it in St. Augustine and Charlotte. Might be worth asking a few more questions of the salesman in regards to how many hours in salt water, and was there any hull damage with the broken trim tab.

http://www.c-brats.com/modules.php?set_albumName=Eressea&op=modload&name=gallery&file=index&include=view_album.php

However, if the boat itself checks out, to me it looks like a pretty good deal.

Colby