Marlin Firearms Forum banner

1 - 17 of 17 Posts

·
Premium Member
Joined
·
4,276 Posts
Discussion Starter #1
Hi folks,
This is the engine that was on the 14' Lund I posted about earlier. During its first test run, when the nearby lakes were still ice free, the engine did not run well for me. So, I did a carb rebuild and cleaning, replaced the plugs and fuel filter, replaced the thermostat, and replaced the lines on the gas tank
I put the engine back on the boat and took it to a small local river for a test drive. It started on the third pull and after adjusting the idle screw and the fuel mix screw, it was running nice and smooth at all speeds, once it was up to temperature.
Now, my question for those that have experience with small outboards, while idling there was blue/white exhaust coming from under the cowling. My 2000 Mercury 8 hp kicker which is near identical to this 9.9 doesn't do this. What could be the cause? Possibly the exhaust gasket?
Andrew
 

·
Registered
Joined
·
6,732 Posts
Could something on the engine have been burning off as it heated up? Especially after the carb rebuild?
 

·
Premium Member
Joined
·
4,276 Posts
Discussion Starter #4
Best thing I think is to run it with cowl off and pinpoint where its coming from.
I gave that a try, but the exhaust fumes blocked visibility immediately. I will try it tomorrow while using a small fan.
Thanks,
Andrew
 
  • Like
Reactions: Maineiac

·
Premium Member
Joined
·
4,276 Posts
Discussion Starter #5
Could something on the engine have been burning off as it heated up? Especially after the carb rebuild?
It's coming up from the base of the cowl. I had everything wiped clean before putting it back together. I will try to pinpoint it tomorrow. I suspect it's an exhaust gasket issue.
Andrew
 

·
Registered
Joined
·
185 Posts
There should never be any exhaust coming from under the cowling The exhaust port dumps exhaust right through to the vents on the leg. Make sure it's warmed up then have a look. The direct air intake is under the cowling. This would choke out the motor quickly. Was the cowling fully seated when you did your first run after the service?
 

·
Premium Member
Joined
·
4,276 Posts
Discussion Starter #7
There should never be any exhaust coming from under the cowling The exhaust port dumps exhaust right through to the vents on the leg. Make sure it's warmed up then have a look. The direct air intake is under the cowling. This would choke out the motor quickly. Was the cowling fully seated when you did your first run after the service?
I had the upper portion of the cowling (lid) off when I was running the engine. The exhaust seems to be coming from under the engine block. I will assume that there is a gasket that sits under it. I wonder if there is damage to it?
Andrew
 

·
Registered
Joined
·
1,616 Posts
My old Suzuki motorcycle smoked like crazy, so do most chainsaws.

Make sure to carry some oars with you though, just in case.
 

·
Premium Member
Joined
·
4,276 Posts
Discussion Starter #10
Just an update on this 9.9 Mercury. I got it running back in December and took it out just before the lakes iced up. It started with one pull and ran just fine. That is until it stopped pumping gas from the tank and I was a mile from the launch. Thank goodness for trolling motors and a fully charged battery.
After I got back home I took the carb and fuel pump apart and discovered my mistake. I had put two thin gaskets together, where there was only suppose to be one on the fuel pump. Now, I would like to hit the water again and see how it runs, but we need to thaw out. Maybe by weeks end the local river will be free of ice.
As a result of this experience and on some good advice from a few folks here, I bought myself a used 20 horse Honda four stroke. It's a 2003 but it is in immaculate condition. I work with the previous owner. He estimates he has about 20 hours on it and it is certainly believable.
Andrew
 

·
Registered
Joined
·
6,732 Posts
Nice acquisition on that Honda 4 stroke. That should do a good job for you for a long time and be reliable, too.

The 4 stroke engines seem to be a lot more reliable than the 2's even if they are a bit heavier. I don't miss the 2 strokes.
 
  • Like
Reactions: alawrence

·
Premium Member
Joined
·
4,276 Posts
Discussion Starter #12
Nice acquisition on that Honda 4 stroke. That should do a good job for you for a long time and be reliable, too.

The 4 stroke engines seem to be a lot more reliable than the 2's even if they are a bit heavier. I don't miss the 2 strokes.
I owned a 1999 Yamaha 40hp 4-stroke. The engine ran well, but a gear in the lower unit failed. That was a $1200 repair. I expect more reliability from this Honda.
Andrew
 

·
Registered
Joined
·
7,586 Posts
Every year you, must check at least once or twice, pull the prop off and make sure you don't have any fishing line rapped around your prop shaft, that cuts the prop shaft seal
And let's water into the gear case, a quick pressure and vacuum test will tell you if your seals are good.
P.s. is that Honda carburetors or fuel injectors?
 

·
Banned
Joined
·
3,193 Posts
don't forget to replace water pump impeller it is insurance for outboards to prevent over heating also do not store any motor with ethanol gas left in fuel system.
gas left in system and overheating are the two most common killers of outboard motors
 

·
Registered
Joined
·
7,586 Posts
I replace a water pump impeller every 3 years.
Every spring my boats are used in the Hudson river for striper fishing, the river is always riled up, lots of dirt and muddy looking water , and pumping that true my motor, bugs me.
And the guys at the launch trying to drive their boat on the
Trailer, and don't have there trailer deep enough in the water, and gunning there motors making roster tails of dirt
And mud at the launch, I shut my motor off
Don't want to pump that grit true my impeller.
 

·
Premium Member
Joined
·
4,276 Posts
Discussion Starter #17
Every year you, must check at least once or twice, pull the prop off and make sure you don't have any fishing line rapped around your prop shaft, that cuts the prop shaft seal
And let's water into the gear case, a quick pressure and vacuum test will tell you if your seals are good.
P.s. is that Honda carburetors or fuel injectors?
This Honda has a carb.
I service my outboards on a regular schedule. The lower unit oil is changed at the end of every season. The impeller is replaced every 2 years, along with the spark plugs (my two stroke engines). These simple tasks keep me on the water without having to worry about break downs.
Andrew
 
1 - 17 of 17 Posts
Top