1967 merc 650 4cyl help

[towman17]

i just bought an old 15 foot grew with an old 67 merc 650 on it..i have never owned a boat before and know nothing about outboards.i hooked a set of earmuffs to it and ran it in the driveway and it seemed ok..put the boat in the water and it was hrd to start..after getting it started it was difficult to keep it running.it then stalled and i couldnt get it going again as the battery was drained..brought her home and charged the battery..started in the driveway and again seemed ok..put fresh gas and tried it in the water a 2nd time.same problem.this time made it about 40 feet away from the dock.at full throttle we couldnt get over 3-4 mph..got it back and died again..very hard to start after that..seems all around the starter and carbs was wet with gas as well as a bunch of gas in the water..i tilted the motor up and gas came out of the top carb..i spoke to one guy and he said the plugs that were in it were the wrong ones so i put the right ones in it and in my driveay it seems a little better..still wet with gas around the carbs..any idea whats going on and what i should look for?? ive also noticed that parts seem pretty much impossible to find..what should i do?? thanks..

 

[turtles11756]

Re: 1967 merc 650 4cyl help

the parts are easy to find. oldmercs.com, crowley marine parts. start with a mercury service manual and compression quage and check compression

 

[doorhanger]

Re: 1967 merc 650 4cyl help

Hi I have the same problem that you do I think. I just posted a similar question. If you get a response please let me know. And I will do the same. I have been messing with this boat for my father in law off and on for a few years and am determined to get it in the water this year. I rebuilt the carbs because they leaked so bad just to start. Then when it was in the water it would sound like everything was fine put the hammer down and it would sound like it revved up like it should but very little movement. Then eventually it would die like it fouled itself out. And would be hard to start just like you described or not start at all. Sometimes it would take off like it should and was fun to drive but it would act up most of the time. I think this is an easy fix it is just a matter of finding someone who knows what it is as I am limited on time. Good luck, Tom

 

[mercfixer]

Re: 1967 merc 650 4cyl help

You might want to start with basics......spark test....compression test....and if they look good,,,go for the fuel system.
If you have the first two you probably have a good shot at it. Those cards are pretty basic and so is the fuel pump. Some of the old...old...little motors used a side float carb like on the old in line six that can be a little tricky setting the float level.

 

[Fuzzytbay]

Re: 1967 merc 650 4cyl help

Plugs...J6C gapped at .30
Leaking fuel, check all of the following:
Fuel connectors at fuel pumps, and bayonet male fitting in motor cowl, and carbs.
Check fuel lines for leakage.
If there are no visable leaks, next though is fuel pump inner gaskets. Kits are 8 bucks in Canada from your local merc dealer, I'd invest in doing it, chances are, fuel is leaking out the backside, into the motor.
Fuel runningout of carb throats when tilted is normal.

Battery drained is a sign of chargeing circuit issues. Mercs of that era need a strong battery to run right.
With it running, check for a charge output from the regulator to the battery.
Make sure the two yellow wires to the regulator are hooked up and tight.
The carbs more than likely need to be rebuilt. but before you do that, check out the engine compression, these motors are awsome to have and run, yet if the compression is shot, it might not be worth fixing this one up. There is a thread in the repair FAQ's, titled link n sync of inline six's, read that and it will help get you started in the right direction.

 

[CV16]

Re: 1967 merc 650 4cyl help

Look for manual here.

http://forums.iboats.com/showthread.php?t=410338

 

[towman17]

Re: 1967 merc 650 4cyl help

Plugs...J6C gapped at .30
Leaking fuel, check all of the following:
Fuel connectors at fuel pumps, and bayonet male fitting in motor cowl, and carbs.
Check fuel lines for leakage.
If there are no visable leaks, next though is fuel pump inner gaskets. Kits are 8 bucks in Canada from your local merc dealer, I'd invest in doing it, chances are, fuel is leaking out the backside, into the motor.
Fuel runningout of carb throats when tilted is normal.

Battery drained is a sign of chargeing circuit issues. Mercs of that era need a strong battery to run right.
With it running, check for a charge output from the regulator to the battery.
Make sure the two yellow wires to the regulator are hooked up and tight.
The carbs more than likely need to be rebuilt. but before you do that, check out the engine compression, these motors are awsome to have and run, yet if the compression is shot, it might not be worth fixing this one up. There is a thread in the repair FAQ's, titled link n sync of inline six's, read that and it will help get you started in the right direction.

if i remove the carbs to clean and or do a carb kit does that mean i have to go through that link and sync process?? and what would you concider to be the minimum level for when i do the compression test?? thanks.

 

[Wingedwheel]

Re: 1967 merc 650 4cyl help

If you rebuilt the carbs and didn't replace the floats you might want to try that.

 

[Moody Blue]

Re: 1967 merc 650 4cyl help

if i remove the carbs to clean and or do a carb kit does that mean i have to go through that link and sync process?? and what would you concider to be the minimum level for when i do the compression test?? thanks.

Don't be intimidated by the link and sync. Its pretty straight forward if you follow the steps, and its ESSENTIAL for your motor to run right.

As for compression readings, the most important result is to have all the cylinders reading within 10% of each other. I'd be happy with anything over 100PSI, and you motor will run with much less but at a lower performance.

 

[towman17]

Re: 1967 merc 650 4cyl help

ok thanks guys..i just downloaded a manual for the motor and im gonna borrow a compression gauge and start tinkering with it over the next few days..ill get back with more info.thanks again..

 

[stubbstheman88]

Re: 1967 merc 650 4cyl help

ok i have had te exact same motor for about thwo years now and i know exactly whats wrong because it happened to mine too>>> first of off u need to do a complete carb job>>> replace as much as u can with the new things they give u>>> U might need to mangle the pins(above the float) becuse the gas today sucks... to fix the electrical problem i would definat6ly look for a short>> the wires that go everywhere are held down by bolts that often come loose and even if the bolt is loose it will still drain your battery completly>>>> i hope this works as well as it did on mine>>> those are some great motors!

 

[towman17]

Re: 1967 merc 650 4cyl help

ok great thanks..after you removed and rebuilt the carbs did you have to go through that link and sync process aswell?? or did you just slap the carbs back on??

 

[Fuzzytbay]

Re: 1967 merc 650 4cyl help

Skip the link n sync and be stuck with one of two things, a motor that dosen't run right, or one that holes a piston. The lync and sync is easy to do, plus today only as an added bonus, I'll throw in this site to the deal!!!!
http://www.maxrules.com/timingindex.html
Go through the menu, pick out your motor, and read away, it will help a bunch I am sure.

 

[towman17]

Re: 1967 merc 650 4cyl help

ok so i was just outside tinkering with the motor and my neighbor came over with a spray can of carb cleaner..while the motor was running he sprayed a small amount into the top carb and it almost stalled..but when he sprayed it into the bottom carb nothing happened..so he did it a few more times with the same result..what could that mean?? he also told me to play with the scew to the right of the carb opening on the front..its a flat head screw..what is that screw for and how many turns out should they be?? i had to stop for a while cause the wife was yelling about the exhaust smell in the house..

 

[towman17]

Re: 1967 merc 650 4cyl help

i tried to download the manual for the motor but its not working so i bought one from ebay..now i have to wait a week or so for it to get here..does anyone have any ideas about whats going on with my carbs whiler spraying carb cleaner while the motor is running as i mentioned in my last post??

 

[Fuzzytbay]

Re: 1967 merc 650 4cyl help

Good that you bought a manual. Now its time to stop guessing whats wrong, and troubleshoot the motor. First if your neigbours not a merc mechanic, or knows a lot about the old inliners, say thanks but no thanks, or you may have a nice boat anchor on your hands instead of a motor. Spraying carb cleaner into the throat of a carb cleans.....the throat of the carb, nothing else, and maybe if its the wrong stuff, scores a clylinder......or worse.
Now to the troubleshooting, your motor needs four things to run. First compression, second spark, third fuel/air mixture and last but not least they all need to happen at the right time, ie timing.
Did you get the compression test done? The bottom carb won't do a thing if the two cylinders it serves have no compression.
Do you have spark on all clyinders? Good spark, get a tester and check.
IF you have those two things then its on to the fuel system, but don't jump the gun, if you keep fidling with stuff, without knowing whats wrong, you just make it harder to fix.

 

[towman17]

Re: 1967 merc 650 4cyl help

ok i think im just going to take off this motor and sell it..i found a 1978 merc 402 40hp for a pretty good price..the only thing is it grinds when you put it into forward or reverse..its not sitting on a boat its on a stand with the controls lying on the grass so not sure if that would affect anything..what im worried about is if this motor is powerfull enough for the boat..my boat is an old 15 foot grew..is the 40hp powerfull enough?? im not planning on doing any water skiing or anything..just putzing around the lakes and some fishing with the wife and kids(two 5 year olds)..i doubt it but maybe pull the kids around in one of those inflatable tubes..anyone have any opinions??

 

[Fuzzytbay]

Re: 1967 merc 650 4cyl help

I am not a big fan of 402's, so my oppinon shouldn't be called upon. As for the grinding, well that is somthing to check out. I'd do the basic tests, compression, visual, plus look at the bottom end oil, plus check the screw looking for metal on the magnet.
On the power end, well dropping 20hp on the boat will be noticable, it should still move it good enough for fishing, as for tubing, well you can almost tube behind any boat...
Shame to give up on the 650, there good motors.

 

[towman17]

Re: 1967 merc 650 4cyl help

ive been told the 650s are great..i just dont know if i should get into doing major repairs on it..im waiting for a friend to bring me his compression tester so i can try to find out why the lower carb isnt doing very much..im worried the rings or pistons are finished..but ill wait till i check the compression before i make a choice..i also found a 1991 merc 30hp..oil injected with power trim..pretty cood price also..will that be strong enough..i just dont want the motor to have to work too haprd to push the boat with all of us in it..im not concerned about speed really.

 

[towman17]

Re: 1967 merc 650 4cyl help

oh and thank you for all the help so far fuzzytbay..