Whaler Central - Boston Whaler Boat Information and Photos

Posted by Joe Emslie on 06/15/14 - 3:58 PM

Went out for our annual Father's Day trip at the 1000 Islands / St. Lawrence and ran into some engine trouble about 1 mile out on our way back. Symptoms on the Mercury were as follows;
1- Loss of power
2- Restart had the power back but sever knocking in the block
3- No oily leaks anywhere
4- Cooling Water was still coming out
5- Shutdown immediately , towed to shore and a quick compression check at home showed 5 cylinders with all 95 - 100 PSI, but one cylinder now has 0 psi.

I will be bringing it to the shop asap but wondering if anyone has experienced something similar and might share the results with me. Or if anyone can offer some advice or prognosis.

Might be the time to repower as I know the 225 hp is overpowered on the rating for my V20.

Other than that it was a great Father's day !!!!!

Thanks Folks for any input you can offer.

Edited by Joe Emslie on 06/15/14 - 4:52 PM

Posted by Finnegan on 06/16/14 - 7:02 PM

Sounds like you threw a rod or something like that. A powerhead rebuild is in order.

Mercury sells rebuilt powerheads for that engine, from the factory. Or you can have a local shop do it.

Another option would be to step up to one of Merc's brand new 150 EFI 4-strokes, For 10K, these are one of the strongest 150's around, and a great deal. You won't notice much of a power difference at all.

Posted by Joe Emslie on 06/17/14 - 3:47 PM

Thanks Finn, spoke with the shop and appears that the cylinders on the port side of the engine are susceptible to this due to the exhaust exiting on this side. It was the top cylinder on the port side. Once I find out more, I'll let you know and thanks for the suggestion on the newer Merc's.

Posted by Joe Emslie on 06/21/14 - 10:15 AM

Well folks, took the head off at the shop and looks like i blew the rings which has obviously caused some damage in the cylinder, piston and head. Being the fact that this outboard is over 33 years old and that we are moving to some big water, Great lakes, I am looking at repowering with something new to give me a piece of mind when out with the family. Don't want to recreate a new thread on repowering, just thought I would give you folks the prognosis.

Posted by Joe Kriz on 06/21/14 - 11:29 AM

That's a bummer Joe but I am glad you know when NOT to spend anymore money on it.

Time to move on.

Let us know here what you put on it.

Edited by Joe Kriz on 06/21/14 - 11:30 AM

Posted by Joe Emslie on 08/08/14 - 3:42 PM

Well Joe, here's the update! My 1978 V20 now has a brand new 175 HP Etec which I am very pleased with. Top end is approx 44 mph at 5300 rpm. Have it used daily for 2 weeks while on holidays and definitely have no regrets. As the mechanic said, wish I would have done it sooner. Obviously much quieter and now can have a "talking" conversation while cruising. Currently have a 16 " Viper on it after trying a 15 & 17. 16 had the higher RPM and planes very quickly.