View Full Version : 97 outback prop question

06-03-2007, 10:46 PM
I just purchased a 97 outback, and noticed that 1/2 to 2/3 throttle is apx 30 mph and 3200 rpm. When I move to full throttle the rpms raise slightly above 4000 but no gain in speed.

When I got it home I slid underneath and did a visual inspection and it is an OJ 13x13. No labeling on LH or RH. (Not sure how to determine from looking at the prop) No damages found to the prop.

I pulled the Nut off after I noticed the cotter key missing, and noticed a slot for a retainer clip between the Dshaft and the prop. IT IS MISSING I'm assuming it is slotted for a clip for a reason and I'm wondering if the prop is slipping at high RPM. ANY THOUGHTS? Do I need the retainer clip?

After reading through some threads on here I found the Poor man's prop puller which didn't work in removing the prop, Didn't try very hard not wanting to damage the prop, and hoping that heat isn't causing the prop to be tighter than normal. (No visible heat markings).

Advice on these two questions would be greatly appreciated. I grew up with I/O boats, and this is my first direct drive.


06-03-2007, 11:00 PM
If you did not remove the prop, there is a good chance that the brass key is in there under the prop..... I just pulled mine this week (my post on Poor man's prop puller). I have an 04 outback and what you describe is exactly how mine acted (but I knew we hit a log/stump). You may want to look real close at all 3 blades and make sure there is not some bend it it. at a glance, mine did not look bent, but when you compared the angle of all 3 blades you could tell that one was distinctly bent. I too had a 13 x 13 LH CUP. I replaced with an OJ XMP 13 x 11. MUCH better.

Good luck.. Also, I sprayed liquid wrench on my shaft to help.

06-03-2007, 11:17 PM
Thanks for the reply.

I just shot a light through the Key hole and I can see daylight through the back side of it, but the key hold is lined up on the Dshaft and the prop. Which leads me to believe this isn't the problem. . . . . .

It doesn't seem to be bent and I have 0 viberation when driving. I need a spare prop anyways I'm checking with a buddy tomorrow to see if I can get a key and order another prop.

I hope the problem is the prop, b/c I ski at 32 mph and sitting wide open to acheive this speed is unacceptable. Only weight in the boat is a small cooler and another person 150#.

Looks like I need to start digging deeper everywhere.

06-04-2007, 02:19 AM
I have a 98 Mobius (Outback hull) and I experienced the same problem when I bought the boat used but the problem was the linkage which restricted full travel. The previous owner had done some modifications. My 13x13 four blade SS gives me has a top speed around 44mph and the rpm is around 4800. Check to see if the carb opens completely.

06-05-2007, 01:48 PM
Thank you all for the responses.
the Key was in the prop, but hard to see.
Prop is getting replaced with a new one and I'm sending the current one out to have it checked and reworked.

I got to looking at the carb and it is a 650cfm quadrajunk Holley. Rule of thumb double the CI to get the CFM.. so 350ci should have a 700 or better cfm. looks like the back two barrells aren't opening up. heading to the house to adjust the spring tensioner while I'm waiting on the new carb.

Thanks again everyone.