Pulley size

Mark 8262

Residential and Commercial Pressure Washing Specia
Can Anyone tell me what size pulleys I need? I have a TSF 2221pump With a Kohler 27 hp engine looking to get 10 gallons a minute at 3000 PSI. Can someone post the formula

Thank you


New member
If you know gallons you want, multiply that times Rated RPM and divide by Rated GPM to get your rpm

TSF2221 (1750 / 10.2 ) multiply times the gpm you want to get, gives you the rpm you need

if you want 8 gpm from a TSF2221 (1750 / 10.2 ) x 8 =1372 rpm

Also the rated GPM divided by the rated RPM gives a number to multiply by your rpm to get gpm

TSF2221 ( 10.2 / 1750 ) multiply times your rpm to get gallons/min

I know there's a chart for this...

Mark 8262

Residential and Commercial Pressure Washing Specia
I just stopped by a gear and pulley machine shop and talked to them. They also said that there is a horse power rating on the pulleys. Although the pulleys I had on the machine were the right proportion the were not the right size (according to them). He told me the pulley I had on there would be hard on the belts. I keep burning up belts on this machine. I had not told him that at the time. He suggested a 5.3" engine pulley with a 10.6" pump pulley with 3 groves. Said this would cure my problem.


New member
For space and weight I want to go with 2 belts. I am going from 3 B-section belts to 2 5V belts, which transmit more horsepower. I think the b-section belts shouldn't go over 10 hp each, so three belts is right. If you're starting over with new pulleys, they are similar price. I think the extra weight of three groove pulleys is a drain on horsepower, but not too sure. Never heard of 3V or 5V belts till recently.


New member
Bigger the pulley's more surface area for the belts to go around. I am running a similar pump, using 2 "b" belts with a big pulley on the pump/engine, 350 hours not a sound yet. I am using cogged belts that are not Chinese, ie Napa or something similar. Only issue with big pulley's is the cost and if they fit under the belt guard.

I have a single belt on a ts2021 with big pulley's 1500 hours atleast not a sound either.


New member
Please help. I don't understand the math I've tried lol. I am using a diesel Kohler kdw1003 says rated 1,500-3600 rpms And pump is GP hp8040 and say 1840 rpm for 8gpm and 4000 psi. So here is my questions
1..what rpms do I run my engine.(what's best)
2..say it is 3600 rpms so then what type and especially what size pully and belt to use.
3.. does the size of the shaft matter. Not the length but the width. I think my pump is 7/8 or 3/4 but the I still have to buy the engine and it comes in several sizes 1" ..1-1/2..1-5/8 etc.
If u can help it would be much appreciated. I am lost lol...

Sirocco Jerry

Active member
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for 1840 rpm pump..
use 3 groove "B" or "5V" belt pulleys.. use a 4.2" on the motor, and 8.0" pulleys
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