What size prop for DT85?

[bjf1280]

I have a 1985 Suzuki DT85 on a 17' center console Bayliner. What size prop should I be running and what should my rpms be running at. I'm not sure what is on it now as its in the water but I'm running at 30mph at 4000-4200 rpm. People are telling me I should be over 5000. Thanks

 

[waffles1]

Re: What size prop for DT85?

You should be running around 5600 rpms. If you think it is because of your pitch you'll gain roughly 200-300 rpms per 1 pitch dropped. If you are running a 15 pitch and drop to 13 pitch you gain around 400-600 rpms. There are a lot of other factors involved but this is a good rule of thumb. I went from 17 down to 13 and gained about 900 rpms. My '88 dt85 came off a different boat and the 17 was too much pitch. Good luck.