Mercuriser 170 hp 3.7 liter exhaust boots

southwest395

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I have a mercruiser 3.7 liter 170hp 4 cylinder. On the inside of the motor on the exhaust theres rubber that connects the pipes. it goes from a four to a three inch. not sure the exact diameter.What cause those to burn or go bad. mines got a hole in it and looks burnt on the inside. this is what mine looks like.0.jpg
 

Don S

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Re: Mercuriser 170 hp 3.7 liter exhaust boots

Poor/no water flow causes the burning. When was the last time the impeller in the drive was replaced?
 

southwest395

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Re: Mercuriser 170 hp 3.7 liter exhaust boots

Just did it this year. How do I find out on a closed cooling system if the impeller is sucking up the rar water. And if its not what cause that problem
 

southwest395

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Re: Mercuriser 170 hp 3.7 liter exhaust boots

I purchased the boat a few months ago and found that the impeller was completely shot, I changed it, but i'm not sure if the damage to the boot was done prior to me changing it, i'm assuming that is the case; However, on the off chance that it isn't, is there anything else that could have caused the damage to the exhaust boot? does it matter what way the rubber fins are turned when its installed ?
 

southwest395

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Messages
137
Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago and

Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago and

I purchased the boat a few months ago and found that the impeller was completely shot, I changed it, but i'm not sure if the damage to the boot was done prior to me changing it, i'm assuming that is the case; However, on the off chance that it isn't, is there anything else that could have caused the damage to the exhaust boot? does it matter what way the rubber fins are turned when its installed on the impeller? I have a mercruiser 3.7 liter 170hp 4 cylinder. On the inside of the motor on the exhaust theres rubber that connects the pipes. it goes from a four to a three inch. not sure the exact diameter.What cause those to burn or go bad. mines got a hole in it and looks burnt on the inside. this is what mine looks like.
 

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Don S

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Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

I merged your two threads on the same subject together, please don't post the same question multiple times.
 

stonyloam

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Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

If your old impeller had fins missing they are probably in the heat exchanger where they can block the raw water tubes. Pop the end caps off and take a look (don't worry only water in there the coolant will not come out). When you install the impeller turn the shaft clockwise, and the impeller will be correct.
 

southwest395

Petty Officer 2nd Class
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Apr 30, 2012
Messages
137
Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

I merged your two threads on the same subject together, please don't post the same question multiple times.
so if i already put the outdrive back together and filled up. do i need to pull it back off and start over
 

southwest395

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Apr 30, 2012
Messages
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Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

i had to have my heat exchanger fixed and plugged two tubes. they did a presure test and it was fine.
 

stonyloam

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Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

Re: Mercruiser exhaust boot 170hp 3.7 4 cylinderI purchased the boat a few months ago

so if i already put the outdrive back together and filled up. do i need to pull it back off and start over

If you think you put the impeller in wrong it would probably be wise to do so.
 
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