Nbra rules for 49ci omc triple

[modifiedoutboard]

was looking at rules for OMC 49 Triple in NBRA book and noticed
number of ports for reed block is not specified?

Can anyone confirm this............

Thanks

[modifiedoutboard]

GROUP 4:
OMC 49.7ci 3 CYLINDER / MERCURY 49.9ci 3 CYLINDER /
YAMAHA 42.6ci MODELS 6H5 AND 6H4 / TOHATSU 42.5ci 3 CYL CUBIC INCHES - 49.7 / 49.9 / 42.6 / 42.5
NUMBER OF CYLINDERS 3 / 3 / 3 / 3 BORE +0.070 - 3.0 / 2.875 / 2.638 / 2.677
STROKE +/- 0.010 - 2.344 / 2.564 / 2.598 / 2.520
NUMBER OF CARBURETORS - 3 / 2 / 3 / 3
REED OPENINGS - N/A / N/A / 4 / 4

[modifiedoutboard]

Whom should I ask about # reed ports in the 49 OMC, would like to make one legal for all sanctioning bodies if possible............

[Larry M]

This is from the NBRA rule book.
A. Must meet bore and stroke criteria.
B. No additional reed cages or carburetors are permitted other than the number specified by the manufacture.
C. No other means shall be used to introduce air/fuel mixture into the crankcase other than the service crankcase and service carburetors supplied by the original manufacture.
D. Reed cages and carburetors must be conventionally located. No size measurements specifications apply to either.
E. Material may not be added to the engine to increase the size of the reed cages. However,material may be removed to do so.
F. Material may not be added to the carburetor to gain a size advantage.

This is for the OMC 49.7 3 cylinder, Mercury 49.9 3 cylinder, Yamaha 42.6,and the Tohatsu 42.5 3 cylinder
NBRA Tech member
Larry McAfee

[Tim Kurcz]

Whom should I ask about # reed ports in the 49 OMC, would like to make one legal for all sanctioning bodies if possible............

You read the NBRA rules correctly: There is no limit to the number of reed openings for SE, but cages must be dimensionally the same as the service 6-port. That said, if you want to build a single engine legal in both APBA and NBRA, the limiting factor is the 6 ports required by the APBA...........

Tim

[modifiedoutboard]

This is from the NBRA rule book.
A. Must meet bore and stroke criteria.
B. No additional reed cages or carburetors are permitted other than the number specified by the manufacture.
C. No other means shall be used to introduce air/fuel mixture into the crankcase other than the service crankcase and service carburetors supplied by the original manufacture.
D. Reed cages and carburetors must be conventionally located. No size measurements specifications apply to either.
E. Material may not be added to the engine to increase the size of the reed cages. However,material may be removed to do so.
F. Material may not be added to the carburetor to gain a size advantage.

This is for the OMC 49.7 3 cylinder, Mercury 49.9 3 cylinder, Yamaha 42.6,and the Tohatsu 42.5 3 cylinder
NBRA Tech member
Larry McAfee

Thanks Larry
The limiting part to this engine is the reed cage, I guess for NBRA I
Will port the reed blocks and add a couple more to it.
Then bore carb to match mod block and port block to match.

See you this summer....


Thanks,

[modifiedoutboard]

You read the NBRA rules correctly: There is no limit to the number of reed openings for SE, but cages must be dimensionally the same as the service 6-port. That said, if you want to build a single engine legal in both APBA and NBRA, the limiting factor is the 6 ports required by the APBA...........

Tim

Wonder list stuff that is not inspected ?

[Larry M]

Anthony, I will be looking forward to meeting you. There is a good field of SE motors in NBRA and I think you will have some good competition.
Larry Mac

[form-e one]

mmmm i only have one port in my reeds,,,mmmmmmmmm

[form-e one]

as far as ime conserned,,, all motors not v-rude,,, should be opened up to compete with the v-rude,,, rule to read all motors bore /stroke,,, front mounted carbs as by manufacture...ie no 2 barrell carbs,,, carbs must be offerd by manufacture of said angine to be used.. just a thought

[form-e one]

ie front case cant be alterd,,,,,,carb studs can be relocated,,, ??

[form-e one]

we need to bring up the other motors to compete with the v-rude and build the class,,,hec even fushlins 60 cuber got beet hands down,,,ssssoo???

[modifiedoutboard]

Anthony, I will be looking forward to meeting you. There is a good field of SE motors in NBRA and I think you will have some good competition.
Larry Mac

I hope to be there and appreciate your help.

regards,