125 Merc question?

[moreyes]

I have a friend with a 125 merc on a Ranger 17' Cherokee. 2 questions,1st is it seems like that boat should be capable of going faster than 41 mph (gps) @ 5200-5400 rpm, not sure of prop other than what al. prop that came on boat? 2nd one when he is running full throttle across the lake it sounds almost like it is missfiring or the prop is slipping then getting traction but the tach doesnt move at all? Any suggestions on a prop and the other issue.

May bait be lively,moreyes

[prchjerker]

Youre probably not going to get anymore speed out of that particular rig.The miss firing or slip noice could be his rev limiter.You do not, repeat do not want to run those inline 4 cylinders over 5250 rpms.Not good on the crank.Another possibility is if hes over trimming and the prop is slipping or cavitating.P.J.

[MR.Pike]

Listen to Perchjerker!! He's right.



<;{{{{{<<( Mr.Pike

[MNNICK]

5250 tops on the RPM alright. Move up in pitch on your prop. I run an aluminum 21 on an 1895 Yar-Craft and I'll run a consistant 40 mph (gps) at around 4900-5000 RPM. Good fishing.

[Eye Catcher]

You keep running that Inline four at 750 above Factory recommended top Rpm and we better not see your name on here bashing Merc when it blows up. (and it will).
To the orginal question it sounds like your motor may be 1 hole to high.
That boat should be able to preform quite nicely with a 21 pitch lazer 2 stainless prop from Merc .