Mercury 35hp prop help

[jhopkins]

I have a 1988 Bass Tracker Pro 17 with a 1988 Mercury 35hp and needing prop advice. I got the boat a little over a year ago and had a few issues with it due to it sitting for a while and this spring I rebuilt the powered, replaced all electronics and fuel related items.

The motor came with a Quicksilver 10.5 x 13p prop that spun 4560 rpms & 23mph. The boat would plane out but took forever. I talked to a local prop shop and put on a Quicksilver 11.25 x 10p and the boat gets on plane much quicker with this prop. This prop spins 5210 rpms & a little over 24 mph. Going from the 13p to 10p averaged 216 rpms per pitch decrease. These numbers are with the trim pin in hole #3, hole #4 the prop blows out when turning.

Since I am below the WOT rpm should I go down to a 9p? My local shop says as long as I'm above 5000 rpms I am good. I don't want to put too much strain on the motor due to low rpms.

 

[ahicks]

You're pretty close now it sounds like. If you wanted absolute max available from it, which may not be a lot different than what you have, from what you say the 9" may do it.

 

[Sea Rider]

What's the min-max factory stated wot rpm range of that OB ? 5210 wot revs were achieved, lightly, medium or heavily loaded ? With deck weight evenly distributed, assume manual trim, should be set for OB to sit at 90?, that's perpendicular to water level. Trim to that fixed position, go for a wot spin and check if having water splashes back or over transom, and if prop aerates at tight close turns at speed on flat calm water cond.

Is current prop an exhaust through prop or an old obsolete one ? If max wot rpm is way more than 5210 ideal would be going for one less pitch to pull wot revs towards max. Will achieve better hole shot than with last one.

Happy Boating

 

[jhopkins]

5400-6000 rpms is the WOT range of the motor. Prop is thru hub exhaust. The stated rpms were with two people without fishing gear so i would say a medium load. Manual trim with pin in 3 hole, when in 4 hole the rpms shoot up when turning.