Good Evening,
Have been working on a SD and have almost got every thing ready for assembly. My question on the pulleys is with your experience what size pulley for the engine and what size pulley for the shaft would you all go with on the following. 18 hp kohler magnum (older),10x8 Hill prop,30'' shaft,1542 lowe. As mentioned I will most likely et it assembled this week, and from there was going to get the pulleys and belt on order. Thanks for any input.

Go to the Gates industrial timing belts web site. Use their Design Flex program to select a belt and pulleys. You will probably be able to be able to run a 1.3:1 reduction or so. You will need to know driver and driven shaft sizes and center to center distance. You will be looking for a Polychain GT2 belt and pulleys.

Thanks mag10,
This imformation is a big help. I hope to be able to order it monday.

Have a couple distributors quote it. Prices seem to vary quite a bit.

Ended up going with McMaster. They were easy to deal with. Next day shipping for eight dollars.
At first we went with the L series belt and pulleys. But when we opened the box it was obvious that it didn't have the strength to do the job. Sent them back and went with the HTD (high torque drive) and are very happy with this series pulleys and belts. Going to try and get the prop shaft finished tommorrow. Mag10 I did take your advice on the gearing and was going wit the poly chain until i seen the price. Have already reached the cutoff point with the budget.

Let us know how it goes. Is the HTD belt the one with the square profile tooth? I have always been a bit skeptical about those belts in a high RPM, high shock load application like a mud motor. If you don't mind me asking, how much does that set up cost through McMaster?

Mag10

Two pulleys,a 1440 mm belt (30 mm width)and two taper lock bushings wer 186.00 and we recieved it the next day. The HTD is an 8mm pitch and the teeth have a radius. The description was for high torque and rpm requirements. Also made mention of being stronger than chain. There was a little bit of instruction on there site that steered me a little in the wrong direction. It suggested to deduct 10 % of the circular length that you need. So I did and questioned the guy on it . But he said that was correct. On a 1440 mm belt that comes up to about 5 and some odd inches. On the second order I made the correction and ordered the circular length that we needed. But like i mentioned they were super easy to deal with. Like every one else we are learning as we go. And one lesson that I have learned is to figure out belt & pulley length and width requirements and build around that. Going to try and finish up this weekend. Gator season is right around the corner. I will post up some pics .