need help identifying this engine

[pontifor]

Hi, I just bought 28' 1973 Luhrs SportFisher and it seems that the engine id plate is missing!! It says '250' on the decal on the electronics housing, looking at service manuals etc I *think* it's a LM340, but I really don't know for sure. Any wisdom this forum could offer would be greatly appreciated.

Cheers,
Stefan

 

[Tahoerover]

Block casting number is on the left hand side of the engine.

 

[pontifor]

ok the block casting number is

4179930-360-1

followed by a large number 6

does this identify the engine? it says 360 in there but it would be nice to be sure.
thanks!
S

 

[Tahoerover]

Must of had a replacement at some time 4179930 is a 360 block used from 1975 to 1993. It may still have 340 heads.

 

[greasemonkey]

Must of had a replacement at some time 4179930 is a 360 block used from 1975 to 1993. It may still have 340 heads.

Which would be an excellent bonus

Pontifor ,on the other side it should have the date,I think the 340s were 235hp?

 

[Tahoerover]

Which would be an excellent bonus

Pontifor ,on the other side it should have the date,I think the 340s were 235hp?

Nope the 340 was 250hp, 360 is 275

 

[pontifor]

Cool, a hybrid. I will check the other side of the block for a date. This motor starts and runs, but at low rpm it stalls when the drive is engaged, any clues on how to diagnose this? I ordered a new ballast resistor but that is just a guess..

thx,
S

 

[Tahoerover]

It may be something as simple as a tune up or idle speed or mixture adjustment.