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[daydreamer1252]

I predicted I would be back. Here I am!

I have a 84 Mercruiser 120 (2.5) serial 6809214 and am going to be replacing it with a reman block and head from a like year OMC. My problem is one source indicated that the carburetor main jets (Mercarb) were different for a 3.0 and a 2.5 engine. I do not know if the "new" engine (bought from and individual who has no memory) is a 3.0 or a 2.5. The head is installed and torqued by the shop that rebuilt it or I'd just measure the bore. I cannot find any reference to the stroke to tell if there is any difference there. Is there any other way you clever people know of to tell the difference or will I have to resort to some Rube Goldberg measurement of fluid through the spark plug hole or something equally "painful"? I don't want to run the engine too lean and ruin the work I am putting into this. All help is, as usual, appreciated...Thanks

 

[Bondo]

Re: On To The Next Question...

Is there any other way you clever people know of to tell the difference

Ayuh,.......

A 2.5l has Only a Pulley mounted to the front of the Crankshaft........

A 3.0l has a Harmonic Balancer,+ a Pulley,..............

 

[daydreamer1252]

Re: On To The Next Question...

Thanks for the reply Bond-o. However all I have is a bare block and head no pulleys no flywheel no lifters, no push-rods, no valve cover, no oil pan just a bare block with no paint and head all bolted up. Is there another way? I hope!!