charging system 1982 thompsom

cub120

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Mar 25, 2023
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how does the charging system work on my 1982 thompsom, it is a 4 cylinder but i can't see a alternator on it. It appears to be charging according to the meter on the dash but don't know what to check or where to find the charger . First time owning this boat so not use to not seeing a alternator or generator. All help would be appreciated Thanks Carl
 

Bondo

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Ayuh,..... Welcome Aboard,..... We gotta know what motor it's got,.....
4 cylinder ain't good enough,..... from Whom,..??.. 'bout what vintage,..??
 

racerone

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Dec 28, 2013
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Perhaps a Mercruiser with the 470 or similar.--Charging system under flywheel.
 

cub120

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Mar 25, 2023
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it is the 470 at least that is what it says on the valve cover so that answers my question. never seen one without a alternator, generator thank you for the response
 

racerone

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There were issues with them.-----Many were converted with a kit with a conventional belt driven alternator.
 

cub120

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Mar 25, 2023
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what kind of issues so I know what to look for and where would I get the conversion kit
 

racerone

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The ----Sierra ---Marine parts catalogue has it.-----List at around $1000 or so.------Find a used one on E-bay ???----Any shop that scraps boats as well.
 

Bondo

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what kind of issues so I know what to look for and where would I get the conversion kit
Ayuh,....... The 470 has many varied potential "Issues",.....

Keep the raw water pump impeller changed every other year,.....
The 470 will Not stand an overheat,.....
 

airshot

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Not a choice motor for most, lots of issues and hard to gets parts and they are costly. I would consider expanding my search to something more popular..
 

Bondo

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Not a choice motor for most, lots of issues and hard to gets parts and they are costly. I would consider expanding my search to something more popular..
Ayuh,....... Chevy based power,...... ;)
 

Scott Danforth

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what kind of issues so I know what to look for and where would I get the conversion kit
Start googling Mercruiser 470 issues.

If your original voltage regulator still works, no need to change to an alternator.

However if the motor overheats as much as 10 degrees, that motor will eat the voltage regulator and spit the head gasket
 
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