# 1rst problem with 25 4 stroke yamaha



## Specknreds (Oct 15, 2008)

I WAS going fishing Friday, but I'm now having the first trouble with my 04' 25hp 4-stroke Yamaha. I took the boat cover off too run the motor and load the boat. It cranked on the first pull (always cranks on first or second pull) but when I touched the throttle it choked out and died. I pulled the cover off and noticed some gas. I pumped the bulb and gas went everywhere. I couldn't see where it was coming from. The carb sits with its side to the motor and you can't see the side or get your hand behind it. I took it to the shop and they said that it was an overflow and that something is stuck. I asked what would cause this and they said "sitting up". It has sat less than 2 months and I know I cranked it at least once in that time. They were saying that every since our local gas stations started serving ethanol, they have been swamped with boats with the same problem. Has anyone else had a problem like this? They assured me that I wouldn't miss my trip Friday, we'll see.


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## ben2go (Oct 15, 2008)

Ethanol blended fuels have a habit of eating rubber and gaskets.I would say the float needle in the carb probably had the rubber end ate off by the ethanol.I've had it happen on other motorized things.When you are leaving the water with the boat,pop off the fuel line, and let the engine run till it dies.Then try to start it to make sure the fuel is gone.This will help keep the ethanol from sitting on vital carb parts and eating them up.


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## Specknreds (Oct 15, 2008)

I was told that it wasn't good to run the fuel out of 4 strokes. I don't know, but I'm calling Yamaha in the morning to find out. My boat normally gets run at least 2 times a month. Should I run the fuel out anyway. 2 months is the longest it has ever sat up. I've been on vacation and been in other peoples boats for the last few months.


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## ben2go (Oct 15, 2008)

Specknreds said:


> I was told that it wasn't good to run the fuel out of 4 strokes. I don't know, but I'm calling Yamaha in the morning to find out. My boat normally gets run at least 2 times a month. Should I run the fuel out anyway. 2 months is the longest it has ever sat up. I've been on vacation and been in other peoples boats for the last few months.



I've never heard of that.I would play it safe and call Yamaha.I'm not sure where or how the fuel is pumped to the carb.The pump could be damaged from the ethanol and leaking gas.


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## dedawg1149 (Oct 15, 2008)

there are alot of post on ethanol about it deteriorating rubber lines and gasket they also say it causes condensation in your fuel tank .get you a water separating fuel filter


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## Specknreds (Oct 16, 2008)

I've got my boat back!!! The spots and dots had better look out tomorrow.

Problem was a cotter pin inside the carb had rusted (should have been stainless). The peices of rust clogged everything. Mechanic said that ethanol could have played a roll in this due to moisture it bonds with.

Found two rubber boots on the linkage leaking a little also. After tearing them down, he showed me that they we eaten from the inside/out. Most likely ETHANOL.

Yamaha said that I shouldn't need to run the gas out. They wouldn't say if it would harm anything either on a 4-stroke. They said to keep good gas in the tank and run it once a month. They said that if E 85 Ethanol becomes legal to use, DON"T, Yamaha will not warranty your motor.

The mechanic charged $127. I thought that this was very reasonable for a carb rebuild and 2 boots.


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## daltonmcgill (Oct 16, 2008)

ben2go said:


> Ethanol blended fuels have a habit of eating rubber and gaskets.I would say the float needle in the carb probably had the rubber end ate off by the ethanol.I've had it happen on other motorized things.When you are leaving the water with the boat,pop off the fuel line, and let the engine run till it dies.Then try to start it to make sure the fuel is gone.This will help keep the ethanol from sitting on vital carb parts and eating them up.


my dad use to do that run all the gass out of it but it sat for 5or 6 years without getting crank and then we tried to crak it and it cranked and ran without nuttin wrong but the impellear is messed up in it


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## Quackrstackr (Oct 16, 2008)

You should try running some of the new Marine Stabil. It is formulated for marine engines having to deal with ethanol.

You never want to run a 2 stroke until it dies but I have never heard that about a 4 stroke. A 2 stroke gets it's cylinder lubrication from the fuel so no fuel, no lubrication for the cylinders until the pistons come to a stop.


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## Jim (Oct 16, 2008)

Glad it's fixed. =D> 

100 bucks is peanuts compared to what a major repair would cost.


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## Waterwings (Oct 16, 2008)

Good to hear about the repair going well, and the low costs! Go catch some fish tomorrow!


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## Specknreds (Oct 19, 2008)

I just refueled and believe it or not, I ran 32 miles (GPS) on 1.99 gallons of gas. I think that the carb job has helped my fuel mileage. I have ran 90 + miles on the GPS on less than 6 gallons. The main area I fish is 13 miles oneway from the ramp. You gotta love 4-strokes and no mixing oil!! It seems a little louder than before, but ran flawlessly.

I need others imput on another issue. The stock prop is 9 7/8 x 10 1/2 and I just put a new prop on 9 7/8 x 11 1/4. Using the GPS I'm running 28.7 MPH with just me in the boat and with 2 people and a full load it's running the exact same. It seems as if I'm hitting a rev limiter??? I hate spending more money, but I think that I'm going to buy a 12 1/2 pitch prop and try it.


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## Zum (Oct 19, 2008)

I have a 30hp,2 stroke.
Went from a 10 to a 13 pitch.I either havn't found the sweet spot yet or it's alittle to much pitch.It's probably alittle to big,wish I had a 11/12 to try.
It will plane with the 13 but I like the get up and go alittle better with the 10.


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## Specknreds (Oct 19, 2008)

If you weren't 2000+ miles away, I'd say lets meet and swap props for a day. Thats a little to far for a $ 75 alum. prop. when I get the right one, I go with a stainless.


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## Zum (Oct 19, 2008)

Stainless is nice,not for the waters I'm fishing though.
I'm not sure but you might want to read up on stainless props compared to aluminum.Again I'm not positive but some people say they have to drop a pitch because the stainless has no give to it.
I guess what I'm saying is maybe a stainless 12 pitch won't be the same as an aluminum 12 pitch in performance.


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