Are Mercury engines worthy??

[TC777]

Hello all, I found a 1977 boat with a mercury engine. I think it is a late 70s model, 70hp. I am new to boating and I do not know much about it. What do you guys think about a 1970s 70hp mercury? The guy said that it has good compression on all cylinders. He said it revs up slow. Any input would be appreciated. Thanks.

 

[JB]

Re: Are Mercury engines worthy??

"Revs up slow" is a bad, bad sign. Probably not making power with all cylinders.

Those were good engines 30 years ago, but not immune to abuse or neglect.

 

[TC777]

Re: Are Mercury engines worthy??

Thanks JB for both the replies, Any suggestions on what to check for with the "revs up slow" situation? Could it be something minor? Or is it more than likely something major?

 

[coolguy147]

Re: Are Mercury engines worthy??

distributor or simple as a carb clean

or worse poor compression

 

[Silvertip]

Re: Are Mercury engines worthy??

Buying an engine with a known problem just because it may be a "deal" generally turns out to not be a deal but rather a money pit. If you are not capable of working on this engine yourself, shop charges will eat up any savings in a hury. You may also find that many shops are even reluctant to work on 30 year old engines anymore because the engine is older than the tech working on it. Be smart and buy a known good rig and by all means, NEVER buy something you cannot test drive so you can experience yourself what "revs up slow really means". I'm betting the real reason is that the engine is worn out and that's why it's for sale.

 

[jbjennings]

Re: Are Mercury engines worthy??

I wouldn't get that motor. Why? it's hard to work on, has expensive electrical parts on it, the lower unit is almost sure to be leaky, etc. etc.
If you don't know how to work on it yourself, you'd better not even consider getting it. As stated, that motor is a major money pit, and even in perfect condition, not worth much, so if you put good money into it, you'd never get it back. I do own a '73 65hp merc and still use it, but it has JB weld on the cracked water jackets, and I have to change the lower unit oil pretty much every time I use it. It's the dreaded 3-cylinder 65hp merc, but actually it runs really nice. I would love to get rid of it, however!:redface:
JMO,
JBJ

 

[TC777]

Re: Are Mercury engines worthy??

Thanks guys, the compression on this motor is 100,100,105. Any more ideas? I appreciate it!

 

[jbjennings]

Re: Are Mercury engines worthy??

My 65hp merc from '73 has 138 to 143 psi on all 3 cylinders.
JBJ