Are you able to change out the gear ratio in a GDSD for make the prop spin faster??

Yep

Do tell .......

You have a 1.4 to 1 reduction on a stock 35 GDSD....
You must also factor in prop pitch to get true "final gearing" !!!

The motor pulley has less teeth than the lower shaft pulley
so for every 1.4 motor revolutions you have 1 prop revolution...

The 27 GDSD has 1.5 to 1 and the 23 GDSD has 1.7 to 1 reduction
so that they all can turn the same 11" 3 blade prop.... The GDSD
prop and the PD are both 12 pitch - MB and GT use a 10 pitch and
less reduction... Hopkins will build you any pitch you like and that
is easier than a pulley change...

More info on this thread...

viewtopic.php?f=3&t=20486&p=382758&hilit=ratio#p382758

Thank you Sir, Right now I am hitting 30mph on the GPS at 4k with the prop deep in the water. If I trim it up it blows it out and hits the rev limit. The boat is a Custom 16.6/48 open plan with a hunt deck (that I want to trade or sale for a GD or GTraxs.) It has a 2 blade on it now and I am not sure if its very worn or not. Would a stock 3 blade hook better and I would go a little faster?

I am happy with the speeds just that it blows out if I trim it higher.

Thank you Sir, Right now I am hitting 30mph on the GPS at 4k with the prop deep in the water. If I trim it up it blows it out and hits the rev limit. The boat is a Custom 16.6/48 open plan with a hunt deck (that I want to trade or sale for a GD or GTraxs.) It has a 2 blade on it now and I am not sure if its very worn or not. Would a stock 3 blade hook better and I would go a little faster?

I am happy with the speeds just that it blows out if I trim it higher.

Sorry for the double post, not sure what happened....

I say don't do it. I had mine stage 2 modded and thought about it, but in the end you would rather have grunt than top speed. If you are stock you will suck in the mud. My .02 cents.

Its a modded motor. I think the prop is worn so I am going to order a 3 blade but still 30mph is pretty freaking fast at 4K rpms. When I trim it to where it "should" be with a little rooster tail it hits the rev limiter mainly due to prop slippage in the water. (cup appears to be going/gone.) I got the motor now I just need a bigger boat!

O I dont run shallow water often and there's not much mud here on the gulf coast. I do have to cross shallow water to get to some deep areas and mostly hunt deep but topped out hydrilla lakes.

damnnnnn i told you it would hit 30 lol....

and im with robin .. you want that ass to get you unstuck , save for the three blade and use the 2 as a spare

Will do!! Yeah its pretty dang fast!! I am sure it would go 32 if I could get it to bite more. It runs great at 4k trim it up a little and WOT it blows it out! its like a half turn from 4k to 4500!!

Love the motor!!

http://www.ebay.com/itm/12-X-12-7-8-Sha ... 232679ebc2
Here is a 12x12 for you and price is affordable. There also are other pitches in 7/8 threaded.

Interesting prop. I see that it is cut for either a 7/8 or Hex!

I want an 1860 or a 2060 so if you see any for sale let me know. Otherwise I am going to wait till Duckmedic gets hard up and wants to trade or sale me his 1660 until I find a bigger one!!