Logo
FULL SITE MENU

New boat no clue Merc 75hp Please help

S

stormy69

New member
"Hi, Im so glad I found this s

"Hi, Im so glad I found this site! Seems like a ton of very knowledgeable and helpful people!

I just bought a 86 rinker with a 75hp Mercury engine. serial #6615110. I am assuming the motor in original with the boat, Looks to be.
Trying to find out year( checked the link to serial number ID. couldn't find it).No other info anywhere on the motor inside or out. From what Ive read it's 50:1 ratio. Please correct me if that is wrong.
No owners manual, is it possible to get one from that long ago? If anyone knows Thanks in advance. Much appreciated."
 
"Welcome to the forum!

Oil

"Welcome to the forum!

Oil mix is right.

Personally, I'd replace the water pump [impeller] and lower gear case lube. Good idea to replace these on an annual basis, not longer than 2 years.

Look at compression, you'll want a reading of 110+ each cylinder on cold motor with throttle wide open [WOT]. Pull kill switch and do with all spark plugs removed to ensure motor swings well.

Check plugs for condition, keep some spare on the rig with tools when the need arises.

Make sure that all the lubrication points are greased well, good idea to pump grease through until the fresh grease shows.

If you flush the motor with the garden hose or in a drum, DO NOT rev over 3k. Motors need the back pressure from the prop to prevent powerhead failure. You'd want to see up to 5500 RPM WOT on the plane. Anything less [< 5k] indicates issues. Wrong prop, poor compression or other issues.

Any motor can last years, IF they're maintained correctly.

These here Olde Sea Dawgs will assist with any queries you might have.


So, there ya have it in'na nut shell!"
 
"most important thing to know,

"most important thing to know, if there is a carb thats got a plugged jet then no gas gets to the cyl, that means no OIL. If you run it, it will burn that cyl and piston. If the engine sat for any time remove and clean the carbs.
75 9126915 - 9167505 1977
75 6432901 - 6613220 1984 4 cyl
75 6613221 - A197881 1985 4 cyl
75 9427676 - 9444515 1985
75 A197882 - C221499 1986 4 cyl
75 9444516 - 1986
75 C221500 - D000749 1990 3 cyl
75 9586000 - 9629999 1990 3 cyl
75 D000750 - D081999 1991 3 cyl + Sea Pro
75 9630000 - 9682499 1991 3 cyl"
 
"You can still get an original

"You can still get an original owners manual from a Merc dealer (at worst they can order it in).

Merc part number 90-110273, runs about 25 bucks."
 
"Thanks for all the great info

"Thanks for all the great info! You guys ROCK!!!!

So I just have a reg mercury motor? No name?
From the list above I gather its an 85? But it only has 3 spark plugs, I thought that made it a 3 cyl. not 4. I'm just a girl what do I know
wink.gif

Thanks again Guys you are great!"
 
"Hmmm, a mystery [img][/img]

"Hmmm, a mystery


Any chance your serial is G61xxxx OR

there is a 4th sparkplug hiding way down at the bottom that you can't quite see because the lower cowl is in the way?"
 
"Hmmm whadda ya know 4 plugs!

"Hmmm whadda ya know 4 plugs! You guys are so smart! I can't thank you enough for being so nice and so helpful. Thanks Benjamin, JB and Graham( here after known as Lambykins
kiss.gif
wink.gif

Now advice on how to share a boat with your brother LOL We went in halves and he wants to fish while I want to tube.... Oh the drama...

I'm sure I'll be back with lots of questions.
Thanks again Guys!"
 
"Hey G, looks like your fan cl

"Hey G, looks like your fan club has taken off!


Idea to share the boat? Uhm, well, fishing is a night sport too...

Only reason why we seem so smart is that our wives help us to post answers here...
biggrin.gif


Happy tubing!!!"
 
Back
Top