Velvet drive info

[rossjo]

Right ... same kit ...

With the Service Manual I posted, he should be good to go ...

[prowlersfish]

Agreed

[~DarkNemesis~]

I hadnt cleaned the bottom yet, but when i did I found this stamp...71B

[rossjo]

71C is in the service I posted earlier today (all 70X and 71X models are - 70A,71A,70B,71B,70C,71C).

[~DarkNemesis~]

Thank you.

[crazyperkdriver]

i have a velvet drive with no tags on it a 70 or 71 or 72 how can i tell what the gear ratio is

[prowlersfish]

if looks like the one in the photo above its a 1 to 1 If it looks like the ones on page 1 then it would be a reduction unit

[crazyperkdriver]

thanks i have a reduction unit

[prowlersfish]

With out the tags it will be hard to tell what ratio it is . It its installed in a running boat then you could use a photo tach to compare engine to shaft speed . If you can tell use what exact model boat and engine , I may be able to what the boat can with . ( no guarantee it was not changed though )

[crazyperkdriver]

motor and trans have been changed but can i just spin the fly wheel side and mark the prop side and spin to see how many times it turns before the prop makes a full rotation will this work ?????

[crazyperkdriver]

which will give more top speed a one to one or a reduction style trans ? i have switched the motor to a 400 hp (stroker 383 full roller motor with a mild cam) it had a mercruiser 260 hp (350) in a 26 ft. sport fisher style hull new motor has a ton of low end torque and i would like to b able to go apx 40 + if possible. which trans would be best to use

[prowlersfish]

motor and trans have been changed but can i just spin the fly wheel side and mark the prop side and spin to see how many times it turns before the prop makes a full rotation will this work ?????

No you can't you need to engage the clutches and that takes a min of 400-500 rpm ( need trans oil pressure to engage the clutches

[crazyperkdriver]

yep have to have clutches engaged tried to check but its like its in neutral thanks for all your help