OMC stringer 800 upper gear case interchangability

[pattyson]

Can I swap an upper gearbox say from a ford 306 to a 3.8l? Does the upper gearbox just changes the direction of the drive, or does is it have a specific gear ratio for the motor? Mine has a cracked housing and leaks. I found one for a 306. Not sure if I need to pull it apart and change the gears. How can you tell what gear ratio they are by looking at the gears, if I need to.
Thanks a bunch
Dave

 

[wrench 3]

The 3.8l has a lower gear ratio than the V8 Ford. If your stuck you could get someone to rebuild the 3.8 case with your gears in it.

 

[pattyson]

Wrench thats what I was kindda thinking. I took apart my old one. So I got scammed on CR and had a guy install this POS. I don't even trust if it is correct for my 3.8l. I wasn't smart enough to keep my old parts. Is there a way to find the ratio? Count teeth on the gears? Anyone know what a 3.8l should be? I'm not a gear ratio guy... What would happen if I put the V8 gearbox on my V6? Sluggish or over rev? Im a fisherman, and very rarely go anywhere in a hurry... I have a kicker motor that I use mostly.

 

[pattyson]

I just counted the teeth on the gears... Input gear 21 output 20. I dont know if that means anything.

 

[wrench 3]

21/20 is the correct gear set for the 3.8l.

 

[pattyson]

Any thoughts on what would happen if I put a 21:17 or 16 geared box on my 3.8l?

 

[southkogs]

On a stringer your gear ratio (and I won't pretend that I fully understand the effect) will also affect your water flow - your impeller is in the base of the upper. IMHO, I would suggest finding the right upper.

Sent you a PM.

 

[pattyson]

Great point Southkogs. Thanks

 

[Bondo]

Any thoughts on what would happen if I put a 21:17 or 16 geared box on my 3.8l?

Ayuh,.... It'll lug to beat 'ell, 'n probably detonate holes in the pistons,...

It won't be able to pull squat for Rpms at Wot, 'n will be Gutless,....

Dependin' on what pitch prop worked with the proper gear ratio, some of the difference could be made up with a prop change,.....

If it were runnin' a 23" pitch prop, ya might drop to a 15" pitch, 'n possibly be sorta ok,...
If it were runnin' a 15" or 17", ya got nowhere to go,....