Diagnosing my Yammy 15hp

Farrukh Ashraf

Farrukh Ashraf

Active member
The motor is 3 season old and never gave any sort of trouble until Sat evening after the hunt. Always starts on first pull but on Sat morning it took 3-4 pulls to fire up, after the hunt it wont start, after many pulls i checked the line, fuel tank but couldn't figure out.Then i tilted the motor up and pulled and it started right away, put it back in position and made it back.Once home i tried to start again but same thing, it just wont start, tilted again and it started right away, any thought guys?? Have to figure it out before next weekend.
Many thanks
Farrukh
 
Pop the cowling...when you pump the fuel line bulb do you see the primer fill? Does it stay filled? You also could be be flooding the carb...I have a 15hp 2 stroke yammie, same one you have? PM me I can help you trouble shoot if you want...
 
could be a few different things could have been flooded, the carb could be gummed up or the fuel line may have air in it. Is the bulb on the fuel line hard? If I had to guess the carb is gummed up and should be rebuilt.
 
Have the same engine too, never had an issue, one pull to start whether it's 60 or 10 degrees out.

I think Larry is spot on with the carb. Do you use any kind of fuel additives for ethanol? Startron? Ringfree? Most issues with engines these days are fuel related due to the ethanol. I have a friend with a 25 yamaha that used to take 7-10 pulls to start and would idle like crap, he didn't use fuel additives. Fresh fuel with the right additives and the engine starts on the first pull every time.
 
Pop the cowling...when you pump the fuel line bulb do you see the primer fill? Does it stay filled? You also could be be flooding the carb...I have a 15hp 2 stroke yammie, same one you have? PM me I can help you trouble shoot if you want...
Click to expand...

Ill try that tomorow David, will let you know if thats the case and ask further advice.Thanks
 
could be a few different things could have been flooded, the carb could be gummed up or the fuel line may have air in it. Is the bulb on the fuel line hard? If I had to guess the carb is gummed up and should be rebuilt.
Click to expand...

Capt. the bulb is hard, but why it would start right away when i tilt the motor??
Farrukh
 
Have the same engine too, never had an issue, one pull to start whether it's 60 or 10 degrees out.

I think Larry is spot on with the carb. Do you use any kind of fuel additives for ethanol? Startron? Ringfree? Most issues with engines these days are fuel related due to the ethanol. I have a friend with a 25 yamaha that used to take 7-10 pulls to start and would idle like crap, he didn't use fuel additives. Fresh fuel with the right additives and the engine starts on the first pull every time.
Click to expand...

Craig i'm using sea foam, have been using from the start of the season, but why it starts right away when i tilt the motor??
Farrukh
 
could be a few different things could have been flooded, the carb could be gummed up or the fuel line may have air in it. Is the bulb on the fuel line hard? If I had to guess the carb is gummed up and should be rebuilt.
Click to expand...

Capt. the bulb is hard, but why it would start right away when i tilt the motor??
Farrukh
Click to expand...


If the engine is tilted the fuel in the carb moves to the lowest point and maybe allowing the air to mix in thus it runs
 
could be a few different things could have been flooded, the carb could be gummed up or the fuel line may have air in it. Is the bulb on the fuel line hard? If I had to guess the carb is gummed up and should be rebuilt.
Click to expand...

Capt. the bulb is hard, but why it would start right away when i tilt the motor??
Farrukh
Click to expand...


If the engine is tilted the fuel in the carb moves to the lowest point and maybe allowing the air to mix in thus it runs
Click to expand...

Does that mean i'm flooding the carb?? and why
 
could be a few different things could have been flooded, the carb could be gummed up or the fuel line may have air in it. Is the bulb on the fuel line hard? If I had to guess the carb is gummed up and should be rebuilt.
Click to expand...

Capt. the bulb is hard, but why it would start right away when i tilt the motor??
Farrukh
Click to expand...


If the engine is tilted the fuel in the carb moves to the lowest point and maybe allowing the air to mix in thus it runs
Click to expand...

Does that mean i'm flooding the carb?? and why
Click to expand...


It's hard to say maybe you are pumping the bulb too much squeezing too hard? like I said more than likely the carb is gummed not an expensive repair the kit is relatively cheap if you can do it yourself. Like Craig said best way to prevent this in the future is to treat the fuel especially in the off-season
 
what mix ratio are you using?
i had my share of issues with fouled plugs, and gummed up carbs,
i started using amsoil 100:1 saber - problems are gone.


good luck!

Dan
 
what mix ratio are you using?
i had my share of issues with fouled plugs, and gummed up carbs,
i started using amsoil 100:1 saber - problems are gone.


good luck!

Dan
Click to expand...

Dan i'm following the mix reccomended by the sea foam , i think its 1ml / gallon.
 
It sounds to me like the float is hung up and not lettling the bowl fill with gas. Once you tilt it the float moves and problem goes away. Get a can of 2+2 carb cleaner. When it doesn't want to start, pull the air breather box off the carb. Spray cleaner down the throat of the carb. If that's the issue, it should try to fire. If so, pull the carb of and then pull the bowl off. Clean the float, bowl and needle valve. It doesn't sound like the jets are clogged, or it wouldn't run right once started. Doesn't sound like a fuel line or pump issue either, it wouldn't start at all or wouldn't stay running.
 
It sounds to me like the float is hung up and not lettling the bowl fill with gas. Once you tilt it the float moves and problem goes away. Get a can of 2+2 carb cleaner. When it doesn't want to start, pull the air breather box off the carb. Spray cleaner down the throat of the carb. If that's the issue, it should try to fire. If so, pull the carb of and then pull the bowl off. Clean the float, bowl and needle valve. It doesn't sound like the jets are clogged, or it wouldn't run right once started. Doesn't sound like a fuel line or pump issue either, it wouldn't start at all or wouldn't stay running.
Click to expand...

Makes sense Kevin, i'll try that ASAP, Thanks.
 
So what was the fix? What did you do?
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Emptied the gas tank completely,put some 2 gal of fresh gas plus almost half a bottle of sea foam, with deep purple 2 sroke oil,ran the motor for a while and started noticing difference in running(smoother), let it run for a while.
Next morning tried again and the motor started right away, again let it run for a while, tried again early morning and started right away again, hopefully problem solved.
 
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