2 Questions. Power tilt and thermostat

[akwalker]

I just picked up a 1973 65 hp 650. When I tilt the motor all the way up, it slowly lowers itself after about a minute. There are NO external leaks in the system. Is it possible the trim cylinders are leaking by internally? If so, where would I find a rebui;d kit for this vintage motor?
Question 2 is, does this motor have a thermostat? I can find one on the engine, or on the parts breakdown. Also, is it normal for the telltale water to **** out with such force that its hitting the water about 10 feet behind the boat? Thanks for any input.

 

[twocycle]

Re: 2 Questions. Power tilt and thermostat

I think condolences are in order here. Sorry but you've acquired one of Mercury's biggest pieces of junk they ever made. They were/are problem ridden to a point that if it is still alive that it's a miracle in itself. That being said here goes. If you don't see an external leak in the trim system then it's leaking internally and probably rebuilding the trim cylinders would fix it, but you need to check to see if you're losing fluid first and if so find the leak. Fill the resevoir full and operate the trim a number of times, probably best when you're using the boat then check to see if the level drops. Only check and/or fill with the trim cyls retracted. (engine in the full up position).
As for the thermostat the answer is YES it should have one unless someone has removed it and as for the water flow from the telltale YEP they will spit a stream that'll scare the fish away.

Hope this is of some value.

Happy boating.
John
Ower/Operator
UB&M

 

[phatmanmike]

Re: 2 Questions. Power tilt and thermostat

jey john.

my 1973 merc 50hp , my 1979 merc 115hp, my 1975 merc 85hp and my 1975 merc 50hp all were absent thermo's. is his 65hp a different thang?

 

[Chris1956]

Re: 2 Questions. Power tilt and thermostat

akwalker, It is possible that the PTT system has air in it, or either one of the piston seals is bad or the control valve is bad. These are not self bleeding, and you must remove the cylinders to bleed them properly. You can get a cylinder rebuild kit from Mercury for ~$40, which will rebuild one cylinder. (You , of course will need to figure out which one is bad.) If you look at the post for the 850 with the leaking cylinder, a procedure is described for replacing the teflon piston seal. I recommend a manual, since you will need it if you plan to keep that motor.

I also thought it did not have a thermostat

 

[Texasmark]

Re: 2 Questions. Power tilt and thermostat

Easy enough to tell. If it has one it should be under an additional appendage cover on top of the existing water jacket cover. If the water jacket cover (that the spark plugs stick thru) is uniform all over when viewed from the rear then you don't have one.

I too feel that Merc didn't add stats till they started building the 3 cyls and that's about when they started looping rather than direct charging.

Mark

 

[lisfisher]

Re: 2 Questions. Power tilt and thermostat

is there a manual release valve on the PTT on this engine? If so , it may just need to be tightened?

 

[akwalker]

Re: 2 Questions. Power tilt and thermostat

I think condolences are in order here. Sorry but you've acquired one of Mercury's biggest pieces of junk they ever made. They were/are problem ridden to a point that if it is still alive that it's a miracle in itself. That being said here goes. If you don't see an external leak in the trim system then it's leaking internally and probably rebuilding the trim cylinders would fix it, but you need to check to see if you're losing fluid first and if so find the leak. Fill the resevoir full and operate the trim a number of times, probably best when you're using the boat then check to see if the level drops. Only check and/or fill with the trim cyls retracted. (engine in the full up position).
As for the thermostat the answer is YES it should have one unless someone has removed it and as for the water flow from the telltale YEP they will spit a stream that'll scare the fish away.

Hope this is of some value.

Happy boating.
John
Ower/Operator
UB&M

Ouch, nothing like telling it how it is, lol. Its funny, but I had the same engine a bunch of years ago on a 16' Starcraft bowrider (less the PTT), and I didn't have a lick of trouble with it. I appreciate the responses. What are the problems you are refering to?

 

[phatmanmike]

Re: 2 Questions. Power tilt and thermostat

akwalker, john musta been drinking or sumthing ....

just kidding.

they are great motors if you take care of them. ever been to oldmercs.com

if you wanna know ANYTHING about inline mercs, contact THIS guy http://cgi3.ebay.com/ws/eBayISAPI.dll?ViewUserPage&userid=clams_canino

Also, there is an online discussion group (newsgroup) dedicated to inline 6's care and feeding! The NNTP server is: news.kraits.org and the newsgroup is: bigweek.mercury-inlines. In Outlook Express use: tools/accounts/add/news and then follow the prompts to join us there!

 

[twocycle]

Re: 2 Questions. Power tilt and thermostat

I've worked on inline Mercs for years guys and most of them are good engines, but it just so happens that the 3 cyl. engine this guy owns isn't one of 'em. They've been know to pop the dome off the top cyl. and burn holes in the dome. That's just for starters. As for the thermostat the very first year they didn't have them so it would be necessary to know the serial number to be sure if this particular one has one and the ones that did have thermostats and aren't on the water jacket cover on the back of the engine, they are under the exhaust housing cover on the port side of the engine. This design was quite different from engines Merc had made before and it's too bad that it didn't work out better. This engine went on to become several other horsepowers later on and it was improved in the later models and horsepowers, but still not Merc's best effort! And to phatmanmike - It ain't an inline 6!

Happy boating.
John
Owner/Operator
UB&M

 

[twocycle]

Re: 2 Questions. Power tilt and thermostat

jey john.

my 1973 merc 50hp , my 1979 merc 115hp, my 1975 merc 85hp and my 1975 merc 50hp all were absent thermo's. is his 65hp a different thang?

Yes the 65 HP 3 cyls. were a different animal. The very first ones didn't have thermostats, but I believe it was the second year they started installing them in them, but only the 3 cyls.

Happy boating.
John
Owner/Operator
UB&M

 

[twocycle]

Re: 2 Questions. Power tilt and thermostat

akwalker, john musta been drinking or sumthing ....

just kidding.

they are great motors if you take care of them. ever been to oldmercs.com

if you wanna know ANYTHING about inline mercs, contact THIS guy http://cgi3.ebay.com/ws/eBayISAPI.dll?ViewUserPage&userid=clams_canino

Also, there is an online discussion group (newsgroup) dedicated to inline 6's care and feeding! The NNTP server is: news.kraits.org and the newsgroup is: bigweek.mercury-inlines. In Outlook Express use: tools/accounts/add/news and then follow the prompts to join us there!

Ain't a 6 inline guy. It's only a 3 cyl. Big difference! I'm a believer in the old inline 6's. Merc made them in various horsepowers over the years. After 1970 they made a 115, 135, 140 & 150 outta that same basic engine. Bigger carbs and power porting & exhaust tuning allowed them to do it. Even so they have two achilles heels. One has to do with the inner water jacket cover on the exhaust side of the engine and the other when they went to the internal bleed system they used plastic (nylon) restrictors that would get sucked out and then the engine couldn't keep from puddling fuel in the intake system. This was mainly an agravation, but the water jacket cover problem actually caused a lot of failures of the more major expense type....................
If Mercury would build the inline 6 today, it would be a great engine and much more reliable because they could cast the block without having to have a removeable inner water jacket cover and they most likely could redesign the bleed system as well. Lost foam casting has done great things for aluminum casting design.
Enough of that. Sorry.

Happy boating.
John
Owner/Operator
UB&M

 

[akwalker]

Re: 2 Questions. Power tilt and thermostat

Okay, Guys, here's the latest with the PTT issue,,,,,, figure this one out. Took the boat to the lake today. Since the trim wouldn't hold the motor in a set position, I put a tilt pin on it so at least I couls get the motor attitude correct. Anyway, I must have tilted the motor up and down about 15 times messin around with the trim. I get home, and tilt the motor all the way up, and now it holds just fine!! Any ideas? Maybe a check valve was stuck and is now free? "Motor, heal thyself"