Steering/Prop handling Problem ???

[klyross]

First time poster - here goes.
Repowered a Ranger R72 with a 115 ETEC (old '94 Johnson 115 that got 'tired'). Using the same SST prop. Pre and post RPM/MPH remained very close (5500 and 42mph). (Initially had trouble with stalling when shifting into gear from idle - this was fixed with a software upgrade.)
Problem - when on plane and making a slow wide angle left turn, occasionally the back end will momentarily push/slide right, before immediately straightening out and tracking straight again (no rpm loss). The closest thing I can think of to describe this action, is a Twitch. The steering does have free play and sometimes seems a bit harder to steer right. We have adjusted the tab under the cav plate - did not seem to help.
I have considered a new steering box, different prop. Hoped to get some comments here before bringin' her in for service.
Thanks...

 

[Dhadley]

Re: Steering/Prop handling Problem ???

That will happen and can be caused by one (or more) of several things. The tip cup can be wearing or worn away. The X dimention may be a little high for the prop condition when turning. You might try trimming in slightly just before turning. A different style prop, like a good 4 blade, may help. Skeg condition and steering condition will all play a part too. Obviously water condition will have an affect.

 

[klyross]

Re: Steering/Prop handling Problem ???

ok, me dumb.
What is a tip cup and X dimention?

 

[Dhadley]

Re: Steering/Prop handling Problem ???

If the tip of the prop has lost it's cup, or didn't have any to begin with, then it will do what you describe. X dimension is basically motor height.

Your top rpm is a bit low but everything may be related to prop condition. Is the prop really an OMC / BRP SST II? What shape is it in?

 

[klyross]

Re: Steering/Prop handling Problem ???

It is a stainless steel prop - that is all I know for sure. The original owner of the boat
put it on and it performed well for the old motor. The prop is in decent shape, it has a
couple dings/nicks in it but nothing I would call major. (but then again, maybe one extra 'ding' in the
right spot could be the final straw.)
I was going to try a new aluminum prop on it -
I guess that could tell me if is a prop issue.

 

[Dhadley]

Re: Steering/Prop handling Problem ???

Please send me a pic of the prop. Dale@props-plus.com

 

[klyross]

Re: Steering/Prop handling Problem ???

Was afraid you might say that -
Boat is in storage in Minn. and I will not be back there
for a month+. So much for trying to get a jump on
spring, eh?