Merc 50hp (500) Power Loss (any more thouhgts)

[paddy87]

early 70s merc 50hp (500) serial not on hand.My problem is hard starting cold,runs okay with just me in boat but no power when under load. Spark is good,carbs have been cleaned filter screens and pump diaphrams replaced.Could it be rings or ???? Thanks.

 

[Fouled Plug]

Re: Merc 50hp (500) Power Loss (any more thouhgts)

Time to invest in a compression tester. $20 should get you a useable one. Check your numbers, and we'll go from there.

 

[paddy87]

Re: Merc 50hp (500) Power Loss (any more thouhgts)

Compresion 123-125 all cyl. Still having same problem,not sure year of motor serial no. 7088895. Do I have points.

 

[ledgefinder]

Re: Merc 50hp (500) Power Loss (any more thouhgts)

Sounds like your prop's too long (too much pitch). Are you new to the boat, or did it run OK before with the same prop?

 

[ledgefinder]

Re: Merc 50hp (500) Power Loss (any more thouhgts)

No points. You've got the 1970-74 ignition setup where the excitation & it's trigger are all in the distributor-looking thing.

 

[paddy87]

Re: Merc 50hp (500) Power Loss (any more thouhgts)

New to boat Pitch is 14 Boat is 15ft. alum. just over 60 inches across transum.

 

[paddy87]

Re: Merc 50hp (500) Power Loss (any more thouhgts)

Motor was a tiller motor converted over to seperat controls and steering, and is new to this boat, probably makes no differance.

 

[tmcalavy]

Re: Merc 50hp (500) Power Loss (any more thouhgts)

check the plug wires, each where it should be? then do a timing/synch to get the carbs synched with the timing advance. Just my 2 cents.

 

[andrewkafp]

Re: Merc 50hp (500) Power Loss (any more thouhgts)

http://www.marineparts.com/partspages/techhelp/TECH15.HTM <br /><br />and<br /><br /> http://www.dougrussell.com/partscatalog/images/MERMAR/74962/43.gif <br /><br />Reckon it's a 1977-78 Canadian motor<br /><br />NB** Thunder Bay looks like a nice place