91 Mercury XR4 low rpms

[JOE54]

maybe 200 rpm , measure the transom from pad to top of transom report back

[Gray2.4L]

Couldn’t get a perfect reading but seems to be 21-21.5 inches from pad to top of transom

[JOE54]

prob 22 " use 3 hole , if it is indeed 21.5 might could use 4th i wouldnt though id get a 6 in plate for it and get it dead on then 3" or higher BELOW pad to center of propshaft and a real good prop

[Gray2.4L]

So have prop shaft 3 inches (or more) below pad? Should be able to get a plate relatively soon. As for prop what do you think I should go with. I could get the 22 worked to 20 to get it up to 5400 and then let the plate do the rest.

[JOE54]

what brand /model/ name on prop----- would wait on that until mtr and set up is spot on

[Gray2.4L]

Right now it’s a Mercury Tempest Plus 22 pitch, after I put in the info from the old 26 on the Merc prop selector website it said 21-22-23 pitch so went with the 22, dropped 4 pitches and gained less than 500 rpm

[JOE54]

good starting place , now get your mtr height corrected and well make some speed/rpms

[Gray2.4L]

Ordering a jack plate, going with a TH marine Z lock 5 in vertical adjustment. What size setback. I was thinking either 4 or 6 setback, 8 or 10 seems a little much. What’s your thought in setback for 18 foot bass boat?

[JOE54]

shouldnt need more than 6

[Gray2.4L]

Ok, read that a good method to do it is mount and lower jackplate as low as it will go, then mount motor and go up holes on the actual motor till best results, then adjust plate from there to get even better results. I think I’m just going to mount it so that jackplate all the way down has the AV plate even with pad, and all the way up should have the av plate 5 in above pad or so

[JOE54]

i do not like mounting mtrs higher than 3rd hole on anything , mount it in 3 hole and start up

[Gray2.4L]

Just got it measured and center of prop shaft is about 7 inches ( +- .25, couldn’t trim all the way down) below pad, once I get the plate I think I’m going to start at 4 and go from there, does that sound about right?

[JOE54]

sounds good ,bet it has to come on up though ,