Fast Fred's OMC Mod 50 secrets Thread #2

[Fast Fred]

a Mod50 rod is 2.344

[Powerabout]

a Mod50 rod is 2.344

do ya mean 4.344 centre to centre?

[Fast Fred]

stroke, stroke is 2.344

[formeone]

over the years ive heard that the boost ports takes away from the torque of this motor???..???

[850cc racer]

single throat carbies on a 49er, race motor. "standard" inside.. changing to the later primer type choke carbs.. what would be a good jet size, the carbies i have are off a 60hp and had 54d's in it.. should i bump them up and to what?

850

[formeone]

on our 49.7 cubers here with free flow exhaust we run .064 hole size jets,,,we just drill our jets out measure with dial indiater,,,, we run same sizes from 3000 feet{ yes we have a race that high} ugg.. to sea level ,,, on our motors here,,, hope it helps...

[Popa Sam]

single throat carbies on a 49er, race motor. "standard" inside.. changing to the later primer type choke carbs.. what would be a good jet size, the carbies i have are off a 60hp and had 54d's in it.. should i bump them up and to what?

850

If they are from a 60 the manifold opening flange is 1.375". If you get carbs from a 70 or 75 they will be 1.5" and perform much better. On the EP that won the Nationals in 89 and 90 we ran .056D most of the time. Ran .0585D in winter.

[Fast Fred]

Tim Kurcz, i was thinkin that the press in liner was mostly cuzz of Heat, that the cast in liner would just over heat, sounds like may be not, ever try the stright in front on a stock case?

[850cc racer]

hey there fred, i know its not a straight in but the FT over here 8port front well the ones i have seen are all cast in blister port blocks. not like our pressed in sleeve mod 50's.. i believe even the early mod 50's were cast in?

[850cc racer]

cheers for the jet reply guys, ive put a set of 59's in them.. i have 56 and 57d's aswell incase we need to change them.

850