Cold-starting O/B

[lockie]

My 2hp Yamaha dinghy O/B is very hard to start on days when it gets down to about 10degC. I try different combo's of throttle and choke, but it's still a bugger. When it finally does start, it runs fine, and at higher temperatures it starts first pull and runs fine.

The plug has done only a few hours, and I have stripped, flushed and cleaned the tank, filter, line and carby and refilled with fresh mix.

lockie

[Jentine]

Check the compression. Low compression will inhibit starting due to blow by but once the parts are warmed, the compression rises enough for normal starts. It should be around 125 psi.

[lockie]

Got plenty of compression.

[Blue Stocking]

Magneto coil is on the way out-- it was on mine to cause that symptom.

[GordMay]

You pull the Choke button out, into the "Start", position, right?
➥ http://www.yamaha-motor.com/assets/s...-03-58_567.pdf

[Blue Stocking]

Originally Posted by GordMay

You pull the Choke button out, into the "Start", position, right?
➥ http://www.yamaha-motor.com/assets/s...-03-58_567.pdf

MY yamaha 2CMH has a little flip lever than you turn from 1 o'clock back to 11 o'clock for choke.
Jus sayin.

[lockie]

Yep, like I said, I've tried all combinations of choke and throttle settings.

[Ex-Calif]

Originally Posted by Blue Stocking

Magneto coil is on the way out-- it was on mine to cause that symptom.

These engine apparently have a reputation for this but improving the spark quality is my vote as well. I dont know what the points setup is on this type of motor either but worn or improperly gapped points are another common spark weakener. Not a factor if electronic.

Cold fuel won't atomize as well producing a lean mixture that is hard to light.

The idle jet would be suspect but you've cleaned the carb properly and it runs well warm.

Better spark could mean better starts.

[Stu Jackson]

I had a hard starting problem some time ago. It was eventually traced to a faulty "kill switch" wiring issue. We'd have to pull the darn thing 60 (!) times to get it going. Now, no problems at all. Check everything out carefully. Evinrude 1990 2 stroke 9.9 hp.

[Blue Stocking]

Originally Posted by Ex-Calif

These engine apparently have a reputation for this but improving the spark quality is my vote as well. I dont know what the points setup is on this type of motor either but worn or improperly gapped points are another common spark weakener. Not a factor if electronic.

Cold fuel won't atomize as well producing a lean mixture that is hard to light.

The idle jet would be suspect but you've cleaned the carb properly and it runs well warm.

Better spark could mean better starts.

Don't know which model he has. My 2CMH Yamaha has CDI ignition. No points, fixed coil-to-flywheel setting. Stop switch is the red plastic "Y" on the tiller. Direct drive.

[Nemo55]

Beginning to sound like an old Classic Motorcycle thread,,finicky carbs at low temp.
I used to get around the problem by using a blow dryer on the motorcycle carb in the mornings, yes i know its not a Motorcycle,,but it is out in the weather all the time just like a Motorcycle.
I would either use a little shot of ether before starting, or increase spark value with a high performance coil.