Merc 500 Thunderbolt serial number help

[JGra]

I have a merc 500 thunderbolt. The serial number is 2516298. I know it is a 1969 but can someone tell me by the serial number what model merc 500 this is. They made 500M, 500ML, 500S, 500SL, 500E,500EL. I am trying to find out what one I have. I dont know if I have a long or short shaft. Its just alot bigger than my Merc 200. Help.

 

[JGra]

Re: Merc 500 Thunderbolt serial number help

Can someone atleast tell me what the measurements are on a long shat and from where to where do you measure. Thanks

 

[Laddies]

Re: Merc 500 Thunderbolt serial number help

Mercury serial numbers could be the same for different model engines built the same year and would not tell if the engine were long or short. Measure from the transom bracket to the cavitation plate a short shaft is about 15" and a long about 20".

 

[JGra]

Re: Merc 500 Thunderbolt serial number help

Thanks, that will help a bunch