70 hp won't start

[still life]

I am writing about my 1978 70hp Seahorse. I am not the most mechanical fella, but have picked up a manual and am interested in learning/doing more diy maintenance. Here is the maintenance that my shop has done in the last year: resealed lower unit, new waterpump, replaced thermostat, carbs cleaned, & float levels set. Comp- 130, 132, 130. I flush it and run the fuel out after every use. The motor ended up running good last summer, catching us a lot of crab!

Tried starting recently (w/ fresh fuel), but it would not start. I took a look at the 'cold start procedures' and feel like I'm following those steps correctly. Plugs look okay, battery is charged, it just won't fire up? Any suggestions or ideas?

Aside from the starting issue, what are your thoughts on these 70hp johnsons? I have a couple buddies that have similar age/hp mercs that start up every time & run awesome. I've already put close to $1k into the motor, & am wondering at what point do I cut my losses and move on? Thanks for your feedback & happy holidays!

 

[kenmyfam]

Re: 70 hp won't start

Did not see a spark test in your post ???
Has it been checked out ??

 

[JB]

Re: 70 hp won't start

Go here, Still Life. http://forums.iboats.com/showthread.php?t=299680

Do "Outboard won't start".

Let us know what you find, and good luck.

 

[still life]

Re: 70 hp won't start

thanks guys, I'll give it a shot.

 

[billy4hp]

Re: 70 hp won't start

I am writing about my 1978 70hp Seahorse. I am not the most mechanical fella, but have picked up a manual and am interested in learning/doing more diy maintenance. Here is the maintenance that my shop has done in the last year: resealed lower unit, new waterpump, replaced thermostat, carbs cleaned, & float levels set. Comp- 130, 132, 130. I flush it and run the fuel out after every use. The motor ended up running good last summer, catching us a lot of crab!

Tried starting recently (w/ fresh fuel), but it would not start. I took a look at the 'cold start procedures' and feel like I'm following those steps correctly. Plugs look okay, battery is charged, it just won't fire up? Any suggestions or ideas?

Aside from the starting issue, what are your thoughts on these 70hp johnsons? I have a couple buddies that have similar age/hp mercs that start up every time & run awesome. I've already put close to $1k into the motor, & am wondering at what point do I cut my losses and move on? Thanks for your feedback & happy holidays!

I have a 1978 70hp Johnson longshaft that run's like a top. Couldn't ask for a more reliable setup than what I have...

Older outboards are pretty easy to troubleshoot and maintain. All they need is fuel, air and spark as long as you have compression. Figure out what your missing and it will fire right up for ya...

I personally do not advocate running any two stroke outboard out of fuel, primarily since the fuel is also the lubrication when you run it out of fuel you are also running the cylinder dry of lubricant and having the carbs set there empty is just asking for a needle and seat assy. to stick...

JMHO..

And Happy Holidays...

 

[Joe Reeves]

Re: 70 hp won't start

(Running Engine Out Of Gas)
(J. Reeves)

If the engine has but one carburetor, it's unlikely that running the engine out of gas would do any harm. When the carburetor runs out of the fuel/oil mixture, the engine stops running.

However, a engine that has more than one carburetor should simply be shut off. The reasoning is that the top carburetor will run out of fuel first due to gravity and the engine will continue to run on because of the still existing fuel in the other lower carburetors.

This results in having at least one aluminum piston running up and down a steel cylinder wall with improper or no lubrication. Not a good idea!

 

[still life]

Re: 70 hp won't start

Billy & Joe- thanks for the heads up on no longer running the fuel out. The folks at the local shop said that running the fuel out was as important as flushing the motor out with fresh water (to prevent carbs from getting getting dirty and gummed up). I agree with you guys and don't like the idea of leaving the carbs dry and un-lubricated.

As far as the motor not starting-
-Checked for spark: good
-Got new plugs, just because it seemed like a good idea.
-Opened up the carb cover and noticed that the flaps weren't opening and closing when I pushed in the choke. Manually moved the linkage to open/close the flaps, and this seemed to loosen it free making the choke button operational again.
-Sprayed some carb clean/starter fluid into the front carb openings (when looking at the spark plugs my brother noticed some water beads on it; making him think there was some moisture in the carbs. thought the starter fluid would help dry out the moisture.)
Finally it started! Ran it for a few minutes. Had to keep pushing the choke in periodically to keep it alive. Was able to idle it down eventually. Planning on taking it out into the bay tomorrow to really let it run. Hoping its good to go?...

 

[billy4hp]

Re: 70 hp won't start

Billy & Joe- thanks for the heads up on no longer running the fuel out. The folks at the local shop said that running the fuel out was as important as flushing the motor out with fresh water (to prevent carbs from getting getting dirty and gummed up). I agree with you guys and don't like the idea of leaving the carbs dry and un-lubricated.

As far as the motor not starting-
-Checked for spark: good
-Got new plugs, just because it seemed like a good idea.
-Opened up the carb cover and noticed that the flaps weren't opening and closing when I pushed in the choke. Manually moved the linkage to open/close the flaps, and this seemed to loosen it free making the choke button operational again.
-Sprayed some carb clean/starter fluid into the front carb openings (when looking at the spark plugs my brother noticed some water beads on it; making him think there was some moisture in the carbs. thought the starter fluid would help dry out the moisture.)
Finally it started! Ran it for a few minutes. Had to keep pushing the choke in periodically to keep it alive. Was able to idle it down eventually. Planning on taking it out into the bay tomorrow to really let it run. Hoping its good to go?...

Still Life,

I'd find another shop IMHO...

Also having to keep choking the engine is a possible indication of a fuel delivery problem (something partially plugged in a carb, weak fuel pump, etc). So if you are going to take it out do it with caution. If there is any indication that it's not running properly, shut it down before some serious damage occurs. Once again we are talking that the fuel is also the lubrication so if it's not getting enough fuel to run properly then it also is not getting enough lubrication which can result in major engine damage in short order.

If it were me, I would attempt to get on plane and then come off plane seeing how the engine behaves. If all is well back on plane and then run up to say 3000 rpm or so and then back off plane to see how everything behaves. If all is well repeat moving up 500 rpm or so at a time. The entire time keep an eye on the water tell tale, etc...

Better to be safe than sorry, especially since you have sunk more money into this engine than it's probably worth if it's running in one piece...

Good luck and Happy New Year,

Billy