Yamaha 115 2 stroke

[lstortini]

I have a 1995 Yamaha 2 stroke and my problem is cold starting. Ever since I bought this engine new in 1995 it gives me problems cold starting. It will caugh and act like it wants to start then it floods. Pull the plugs, let it dry out and then it will start. When I pull the plastic carborator guard from in front of the carbs and spray starter fluid into the carbs it kicks off and keeps running. Once the engine runs for a couple of minutes I can turn it off and it will start back up with out a problem everytime and will continue to start all day once out on the water. It's tha initial cold start that is giving me problems.
I have changed the fuel/water separator and filter to a higher grade micron filter, I changed the plugs and I am mixing the fuel/oil to a 50:1 ratio. I use the best oil (yamalube) and I burn 89 octain fuel. What is the problem? Can anyone give me some sound advice on how to correct this problem.
Thank you,
Lou:

 

[BruceAML]

Re: Yamaha 115 2 stroke

The first thing you need to do is give us the complete model number from the data plate. Tell us what spark plugs you are using and the gap and torque of the spark plugs. Were the carburetors ever rebuilt and do you have the owner's manual? What position is the choke in when you start?

 

[lstortini]

Re: Yamaha 115 2 stroke

The first thing you need to do is give us the complete model number from the data plate. Tell us what spark plugs you are using and the gap and torque of the spark plugs. Were the carburetors ever rebuilt and do you have the owner's manual? What position is the choke in when you start?

- Model Number: C115TXRT
- Spark Plug: NGK B8HS10
- Plug Gap: 0.039
- Hand tightened until spark plug is properly seated
- Carburetors have never been rebuilt
- I can not find the owners manual
- I normally use the manual choke and in cold weather I set the c
oke on full and in warm weather I set it on anywhere from full to 1/2 to 3/4.

Bruce,
While surfing the net and finding you, I also came accross a man with a Evenrude Ficht 115 that had the exact problem I did and this guuy who calls himself The Marine Doctor suggested that his problem could be the temp sensor. He stated that the temp sensor delivers the temp to the ECM...the ECM then uses that data and combines it with the other data it obtains from other sensors...checks a plotting graph...then supplies the correct amount of fuel.
This is all greek to me! I'm a cabinet builder and woodworker, mechanic work is far from my feild of expertise. What do you think about this?
One last thing, when I say cold start I mean after the engine has sat for a week or two no matter how cold or warm the temp is out side.

 

[douglloyd]

Re: Yamaha 115 2 stroke

The Johnson is a Different animal-
Cold start procedure-Lower motor, pump bulb till hard, open throttle pump once or twice set at high idle,turn on key,flip up choke switch(did you hear it click?)now engage starter motor. should kick right on within a second or two.
Warm start, turn on key. all joy lets go!
Now if it is not doing that you need to go down the maintenance list.
Does the choke butterfly close completely?
Have you replaced the fuel pump?
Have you replaced the Thermostats?
Have you had the carbs taken off and cleaned out?
Good luck! It is a simple motor keep the diagnosis simple
SUCK_BANG_BLOW that's it.

 

[lstortini]

Re: Yamaha 115 2 stroke

OK Doug, I will follow your instructions and see how it goes. I let you know if it worked. Thanks for your help and concern.......Lou Stortini ,CPO, USN(ret.)

 

[Bodean2]

Re: Yamaha 115 2 stroke

I have a 2002 115hp and had the same problem. If you choke by pushing the key in, check to see if your solenoid that actuates the choke is adjusted properly. Take the cover off of your engine. The solenoid is located, as you look a the front of your engine, on the front left of your engined above the carburator. It is attached with 2 bolts. Loosen those bolts and slide the solenoid up (it is adjustable). then tighten. this will tighten the choke linkage. if the choke does not close all the way, it will have a hard time starting when cold. this takes 5 minutes. It fixed my starting problems. Please try this before anything else. It works!