Cold starting Yamaha

Yesterday I managed to kill my start battery trying to start my 55HP 95 Yamaha. When I got home I hooked up the on board charger and after about 10 minutes I hit the starter and of course it fired right up. I am going to take the cables off and clean them and replace the wing nuts with regular nuts. However, the battery spun the motor for a good while before it ran down, so my question is, how do you guys start your 2 stroke carb Yammys? I went through this with my Mercury a few years back until I learned what it wanted. Any tips on how you start yours. I was told by the guy that installed it to raise the fast idle up to full, press the choke button and fire it off, releasing the choke when it fires. This is cold starting first thing in the day. After it has been started once it fires right up for the rest of the day. Battery is 5 years old, but it seems to take and hold a charge. This is the first time I failed to get it started, even though it has been balky cranking the first time. I have been told this is uncharacteristic of Yamahas motors. It is a remote control console type motor.

It's going to start easier out of the water due to no back pressure or water drag. I would check the basics. Timing, carb settings, spark intensity and voltage drop while cranking. You may be using too much choke. My buddy did that to his yammy. Was used to his old merc. Crank then push choke til it started hitting. He would flood his before it was spinning long enought to catch.

Yes that is how I finally learned to start the Merc. I may try starting without the choke and see if that helps.

Take the air box cover off and actuate the choke, bet you will find that the choke valves, butterflies some might call them, are not closing fully due to binding or the choke solenoid not pulling to the limit of its travel. That motor should be forgiving of a little extra fuel at start up, not easily flooded.

Ray,
I see this all the time on Lake greenwood people put their boats in and the first thing they do is hop on the key trying to start their outboards cranking and cranking and nothing !!! what I always ask them is do you have a firm bulb they go what? I say pump the bulb on the gas line until its firm and give that a try Bam!!! outboard fires right up!!! make sure you got a firm bulb and see if that helps !!!

I always pump the bulb up firm before the boat hits the water, just part of my launch routine. Might try different methods, such as half choke, 2/3's choke, etc., every OB is a bit different for one reason or another on those cold starts. You'll find the secret soon.

150 yammi 2 stroke, firm bulb, pull choke, fast idle all the way, starts in about 4-5 seconds every time when it's cold. After the first start of the day just hit the key and she goes, on mine at least.

If your motor has the enrichment type carb. I would lower motor crank about 4 sec. Then rase fast idel and push in on key and crank about 10 sec. It should crank. You need to pressure the crankcase first.

get a 4 stroke

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Originally Posted by Mickey

If your motor has the enrichment type carb. I would lower motor crank about 4 sec. Then rase fast idel and push in on key and crank about 10 sec. It should crank. You need to pressure the crankcase first.

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His motor has a choke.

Here is how I used to get my 1992 - 85hp yami to start
1) Pump bulb till hard
2) Trim motor all the way down (to let gravity help getting the fuel into the intake) If motor is not at least level, preferably tilting back, the fuel will run out the front of the carb instead of into the intake.
3) Raise fast idle lever half way
4) Push key to choke
5) Hold choke while cranking
6) Once started let choke go, feather it if the motor starts to die
7) Lower idle lever as rpm's increase

most Yamaha motors have a non vented gas tank. What that means is: disconnect the fuel line from the motor every time! A little temperature rise willl flood your motor every time if you don't. My Yamahas start if you just look at them and smile!

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Originally Posted by Rambored

most Yamaha motors have a non vented gas tank. What that means is: disconnect the fuel line from the motor every time! A little temperature rise willl flood your motor every time if you don't. My Yamahas start if you just look at them and smile!

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Got to be vented somehow or would suck the tank in, I think anyway

My Yamaha is on a Skeeter BBoat and the gas tanks are both vented. Don't know about others.

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Originally Posted by Rambored

most Yamaha motors have a non vented gas tank. What that means is: disconnect the fuel line from the motor every time! A little temperature rise willl flood your motor every time if you don't. My Yamahas start if you just look at them and smile!

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The tank that comes with the motor (when purchased new) has an "auto venting" cap. It is just like the older OMC tanks. There is not a value on it to close. It vents automatically.

new spark plugs will go a long ways to solving your problem if you haven't put any in new for a long time. The 2 strokers foul the plugs pretty easy with oil making them hard to start.

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Originally Posted by clfarms1

new spark plugs will go a long ways to solving your problem if you haven't put any in new for a long time. The 2 strokers foul the plugs pretty easy with oil making them hard to start.

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fuoul
Mine don't. I haven't changed plugs in any of my 2 stroke outboards in years and they start very easy. I like the firm primer comment, and the suggestion to remove the airbox to see if the choke is closing fully. If the choke doesn't close fully or the fuel bowl on the carb is not full, it will be hard to start. No doubt checking the plugs would be wise, I just don't find that they foul very easily....... I run several OLD 2-stroke outboards and they all start very easily cold or warm. Both 4-strokes and 2-strokes are hard to start when a part is not working properly or when the engine is not tuned correctly.
JMO,
JBJ

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Originally Posted by bayoumonster

fuoul
Mine don't. I haven't changed plugs in any of my 2 stroke outboards in years and they start very easy. I like the firm primer comment, and the suggestion to remove the airbox to see if the choke is closing fully. If the choke doesn't close fully or the fuel bowl on the carb is not full, it will be hard to start. No doubt checking the plugs would be wise, I just don't find that they foul very easily....... I run several OLD 2-stroke outboards and they all start very easily cold or warm. Both 4-strokes and 2-strokes are hard to start when a part is not working properly or when the engine is not tuned correctly.
JMO,
JBJ

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It gets a little colder up here, when it was about 20 the other day my buddies 2 stroke started hard, new plugs got down to about 7 and started alot better. But I agree with your comment that not tuned correctly is probably what is wrong.

Indeed...... I'm from Louisiana and don't really know what really cold weather is compared to you guys. Didn't think about the extreme temps' affect on plugs/starting.
Good fishin',
JBJ

Thanks for all the suggetions fellows. I am still trying to find the right combination. When I figure out what it wants I will post the results. I spoke with the shop where I bought it and he told me a couple of things to do, so gonna give that a shot next.
SeaRay

I have yet to find an outboard this doesnt work on. If you push the choke in then turn the key the choke may not be working. raise fast idle to about half way, turn the key on THEN push the choke in, Then crank. Continue to hold the choke in until the motor ALMOST stalls THEN release the choke. Had a 75 mariner that I would have to crank at least 25 times before it would stay running. Never had to crank it more than once after started using this method. Hope this helps

Well I got this far. It will fire up, but as soon as I release the choke it dies. If I keep clicking the choke on it will rev up then die when I release. Course I get a ton of smoke because the mix is so rich. I checked the hose at the motor and gas sprays out when I depress the ball cock in the fitting. The hose assembly is new, and yes it is installed correctly with the arrow toward the motor. Seems like I am not getting gas to the carbs. May be headed back to the shop where I got it. Just trying to avoid a 50 mile trip one way.

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Originally Posted by SeaRay

Well I got this far. It will fire up, but as soon as I release the choke it dies. If I keep clicking the choke on it will rev up then die when I release. Course I get a ton of smoke because the mix is so rich. I checked the hose at the motor and gas sprays out when I depress the ball cock in the fitting. The hose assembly is new, and yes it is installed correctly with the arrow toward the motor. Seems like I am not getting gas to the carbs. May be headed back to the shop where I got it. Just trying to avoid a 50 mile trip one way.

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Sounds like the Idle jet is clogged

This is probably not going to make sense but while I was waiting to hear from my mechanic I got to thinking that the motor seemed like it was not turning over as fast as it should. I checked the battery and it was fully charged so I took the terminals off and found the + lead was corroded so I cleaned it and replaced the wing nut with a regular nut, did the same for the - terminal. Tried to start it again and it fired right up. Once it catches and runs for a minute or so, it will start back up immediately so I will try it again with a cold start tomorrow. Could low voltage have been keeping it from starting?? Since it would fire up and then die, I was sure it was a gas issue. Sounds too simple but I will try it over the next few days and see if it cranks.

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Originally Posted by MDCrappie

Sounds like the Idle jet is clogged

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+1 for me. Classic symptom of a clogged idle circuit. Low battery voltage won't cause it to run and die like you describe, but can eventually ruin expensive electrical components.

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Originally Posted by MDCrappie

Sounds like the Idle jet is clogged

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:hesaid

Once you get all your connections cleaned, get some copper coat gasket maker. Spray it on everything as you put it back together. Then coat the top of everything when you are done. Works VERY well. I use it in the shop all the time. Its also great as gasket maker...its actual purpose...lol.

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Originally Posted by bayoumonster

+1 for me. Classic symptom of a clogged idle circuit. Low battery voltage won't cause it to run and die like you describe, but can eventually ruin expensive electrical components.

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This is an older motor(1995). Was the idle circuit electronic on this motor?? Old as it is I figured it was mechanical and ran off the magneto circuit on the flywheel.

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Originally Posted by SeaRay

This is an older motor(1995). Was the idle circuit electronic on this motor?? Old as it is I figured it was mechanical and ran off the magneto circuit on the flywheel.

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No not electric - it is just passages for air and fuel. The comment about damaging the electronics with the low battery is separate from your fuel, but he is right. Some of that vintage Mercury could catch fire if the battery was disconnected while running.

I have a Mercury 115 HP built in 1989. I learned that mine had to be level or it wouldn't start. If I left the motor tilted up at all it was a bit$h to get started when cold.

It tried the motor today, after it sat out in 30 degree weather overnight and it fired off time I hit the starter. Real test will be Friday when I go at daylight and try it on the water. Sure sounds like it turns over much faster now though.

so, I did not see anybody mention that Yamaha is a non vented gas tank. EVERY TIME you put the motor on the trailer pull the gas line and allow the motor to run dry. Next time you put the boat in the water crack the gas tank cap to relieve pressure and then connect the gas line and firm the bulb. A yamaha should start with pull starter or electric immediately. If it does not you probably need new plugs. I am speaking from experience with small two strokes, but I believe all Yamaha tanks are non vented.

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Originally Posted by Rambored

so, I did not see anybody mention that Yamaha is a non vented gas tank. EVERY TIME you put the motor on the trailer pull the gas line and allow the motor to run dry. Next time you put the boat in the water crack the gas tank cap to relieve pressure and then connect the gas line and firm the bulb. A yamaha should start with pull starter or electric immediately. If it does not you probably need new plugs. I am speaking from experience with small two strokes, but I believe all Yamaha tanks are non vented.

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Not that it's a big deal, but I don't believe that's possible. The tank MUST be vented for two reasons: 1) there would be a vacuum that the pump couldn't overcome if there were no vent to allow air in the tank to replace the lost fuel, and the engine would stall due lack of fuel. 2) As the summer sun heated the tank, there could easily be enough pressure generated to cause the plastic tank to split and spew fuel all over the boat.
JMO---I've been wrong before. :)
JBJ

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Originally Posted by Rambored

so, I did not see anybody mention that Yamaha is a non vented gas tank. EVERY TIME you put the motor on the trailer pull the gas line and allow the motor to run dry. Next time you put the boat in the water crack the gas tank cap to relieve pressure and then connect the gas line and firm the bulb. A yamaha should start with pull starter or electric immediately. If it does not you probably need new plugs. I am speaking from experience with small two strokes, but I believe all Yamaha tanks are non vented.

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Couple things wrong here:

DO NOT pull the fuel hose and "let the motor run dry" on any multi-carb motor. If one carb runs "Dry" before the other then you will have the motor running with the cylinder(s) fed by that carb running WITHOUT lubrication. Not a good thing. Probably won't blow the motor there, but will likely cause damage.

Yamaha tanks ARE vented. Here is the description:

Galvanized Fuel Tank Meets tough NMMA/BIA and ABYC standards. Includes auto-venting and level gauge. Suitable for premix and automatic oil injection. Made with galvanized coating for superior corrosion resistance. --- CAP ASSY, CAP ASSEMBLY

I was told by an BIA certified instructor at a small outboard repair class the same thing about running the gas out, which is why you should always use a stabilizer in your gas. He said never run the gas out, because of the lack of lubrication as the bowls empty. Also, my tank is a built in tank, which is the same tank used on any make outboard so whatever it is, they all are, cause I had a Merc on here before I put the Yamaha on. It is my belief that they are all vented on most current models. The trouble was in fact a corroded battery cable on the + lead. Once I cleaned it up and replaced the wing nut with a regular nut and tightened it down it cranked almost immediately. Started it right up this AM when the temp was 38 degrees. Learn something new everyday. I never would have believed this was the problem.

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Originally Posted by SeaRay

I was told by an BIA certified instructor at a small outboard repair class the same thing about running the gas out, which is why you should always use a stabilizer in your gas. He said never run the gas out, because of the lack of lubrication as the bowls empty. Also, my tank is a built in tank, which is the same tank used on any make outboard so whatever it is, they all are, cause I had a Merc on here before I put the Yamaha on. It is my belief that they are all vented on most current models. The trouble was in fact a corroded battery cable on the + lead. Once I cleaned it up and replaced the wing nut with a regular nut and tightened it down it cranked almost immediately. Started it right up this AM when the temp was 38 degrees. Learn something new everyday. I never would have believed this was the problem.

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That's great that it's fixed and wasn't high $$. If not already you may want to put a "Nyloc" nut on the batteries terminals so they are less prone to vibrate loose.

my 06 50 hp 2stroke yammy has a very particular sequence that it likes. If i deviate from this it tends to take quite some time to start.

1) pump up bulb to make sure fuel bowl is full

2) do not lift the fast idle lever at all (not even a little)

3) Push in the key so that when you are turning it the motor automatically engages the choke. Turn over for 4-5 seconds

4) she will start once and sputter on the second turn over, then will die again. 3rd time she runs good, after 5 seconds of running i raise the fast idle a bit to get her idling a bit faster and let her warm up for a few minutes before gettin a move on.

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Originally Posted by Prowler

my 06 50 hp 2stroke yammy has a very particular sequence that it likes. If i deviate from this it tends to take quite some time to start.

1) pump up bulb to make sure fuel bowl is full

2) do not lift the fast idle lever at all (not even a little)

3) Push in the key so that when you are turning it the motor automatically engages the choke. Turn over for 4-5 seconds

4) she will start once and sputter on the second turn over, then will die again. 3rd time she runs good, after 5 seconds of running i raise the fast idle a bit to get her idling a bit faster and let her warm up for a few minutes before gettin a move on.

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Try lifting the fast idle a little. turn the key on THEN push in the choke, then turn to crank, hold the choke in til motor almost goes dead then release the choke. When I did this I never had to crank my motor more than once