Starting & warm up

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
I notice that when I start the 40hp in the water with the motor tilted up (enough to clear the launch ramp in shallows) but down enough to pump water it runs really bad. Its hard to start, needs lots of choke to stay running, makes lots of smoke and feels like its running on one cylinder for a while until it warms up then it's OK.<br /><br />But if I wait until the boat can be shoved off to deeper water and drop the motor all the way down before starting it runs great. It starts easy one or two "squirts" of choke warms up quick and no smoke.<br /><br />Shouldn't this motor run OK when trimmed up a bit?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: Starting & warm up

Float level set a tad too high. Carbed two strokes need lots of fuel when cold so bump the choke a time or two as needed during warm up if there is a tendency to stall. Raise the fast idle lever a little to let it warm before pushing off. You can hear it in the engine note when she's ready to go.
 

BF

Lieutenant
Joined
Apr 8, 2003
Messages
1,489
Re: Starting & warm up

my merc V6 just plain won't start if it's cold and tilted up. Once started, it can be tilted up w/o a problem and stays running. I still remember us running the battery out the first time we tried to start it trimmed up (the purchase felt like a big mistake for a while there) :)
 

MarkHPCA

Petty Officer 2nd Class
Joined
Jun 2, 2004
Messages
145
Re: Starting & warm up

Wouldn't the reduce back pressure in the exahust due to being partially out of wthe water effect the running?
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: Starting & warm up

At low RPMs, a lot of fuel puddles in the crankcase. Tilt the motor towards the carbs and the puddling gets deeper delivering even less fuel to the cylinders. Add cold motor to the equation and the results are predictable. 2-strokes like to be tilted a bit towards the cylinders for easier starting.
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Starting & warm up

Just a quick update: Have made a point of starting the motor in the full down position and it has been running great. When the carbs come off for a cleaning I'll check the float level to be sure it's not too high. I couldn't find anything in the owners manual about running with the motor tilted up, but I suspect it should run right.
 
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