1988 Black max 200hp overheating

[VkingMike]

I was somewhat confused by the bare block and 1 pc heads also. If it's an 88 200 it's certainly not a fishin motor.

Rock

My thoughts as well.

[whitehead249]

Og787233

[whitehead249]

So I’m guessing it’s a 1987 then?

[rock]

So were there no numbers or letters behind the timing arm?

Rock

[whitehead249]

[LakeFever]

Lucky bastard that’s a 225 promax block. Gotta run the good fuel in that one. No ethanol 91 oct minimum. Might want to pull a head, cc it and measure the head gasket thickness. Could be your issue right there

[rock]

Does look like an NN stamp. Can you show a pic of the side of the engine.

Rock

[skialot2]

Congratulations!!! you got a nice motor!!!

Serial number that starts 0G7***** Is probably a 1997 or 1998

0G3******* is a 1996. So, it has to be newer that that.

[whitehead249]

[whitehead249]

[whitehead249]

I will get more pictures tomorrow if I need more to help y’all out.

[David - WI]

[rock]

That is what is commonly known as a Frankenmerc. Definitely a 225 Promax block but with carbs. And no fuel pump.

Rock

[whitehead249]

So needs to have a electric fuel pump?

[whitehead249]

A couple more questions should I run it with the tstats and poppet valve? I also put a different lower unit off a Mariner 150 i was wondering if that could be some of the problem? Any and all help would be appreciated.