1994 225 Evinrude -proper set up

[Sand Bass]

I have read how important it is to prop this motor near max rpm. My boat will turn 5800 rpm wot. To get it there I have to trim motor all the way up and give it full throttle for probably 15 seconds. Problem is I rarely run boat wot. Most of the time I run motor from 2500 to 3500 rpm and trimmed somewhere in the middle. My question is that since I do not cruise with trim all the way up should I prop for more rpms (full 6000)? Boat is a 20'6" Champion bass boat (1995). I cannot raise motor much more because prop looses its bite on the water. Prop is a 24 raker that is flawless.

 

[Reel Appeal]

Re: 1994 225 Evinrude -proper set up

Sand Bass,<br /> Try a prop with the next lower pitch,such as a 23 or 21.Should bring up rpm's and reduce motor load(strain).Speed difference should be minor(if any)....

 

[Hooty]

Re: 1994 225 Evinrude -proper set up

You sure could do that and it would keep the revs up during cruise. I'd just be careful and not over-rev when going to full power.<br /><br />c/6<br /><br />Hooty

 

[Dhadley]

Re: 1994 225 Evinrude -proper set up

The rev limiter is at 6700. If the Raker is losing bite at a higher X dimension it may be time for a prop with more technology (bite). Raising the X dimension and staying with the same pitch (in a different style prop) should raise the top rpm's, improve the holeshot, reduce the load on the engine at ALL rpm ranges and extend the life of the motor.<br /><br />Good luck!

 

[Sand Bass]

Re: 1994 225 Evinrude -proper set up

Real Appeal, I was thinking of dropping to a 23 but raker makes only even number pitches so I would have to drop down to a 22. I do not know anyone with a bass boat and a big v-6 running that low pitch so I figured it would not work well (too much over max rpm)(6k). I think turbo makes odd number pitches but I have not found one that I would buy (I am paticular when purchasing used prop). Dhadley, do you have any prop suggestions that would not be too expensive? My wife had a fit when I purchased the raker for $275.

 

[Dhadley]

Re: 1994 225 Evinrude -proper set up

Ah, a Raker for 275.00. It must have been rebuilt at some point. If so its possible someone used SST pitch blocks to do so and it lost all the lift a Raker normally has. Especially a 24 Raker. I would look at a 4 blade 24 Turbo or at least a 24 Stiletto. Both are great props and I prefer the Turbo because of the larger diameter. I rarely see a used one for sale. <br /><br />Have no fear about the rpm. Its a needle bearing two stroke motor. There are no valves to break or hit the piston, there are no lifters to "float" nor push rods to worry about. The reeds in your motor work well at 7000+ and the (stock light) rods in your motor work up to about 9500 rpm. Your ignition system will start to reach its limit at about 7200-7400 rpm. Once you get there we'll tell you which components to get to go further. Right now we need to concentrate on a prop. Your set up is really good now but if you'll post accurate top speed at 5800 we can calculate % of slip.<br /><br />If I hear of any used props I'll let you know. Right now all I have are new ones.<br /><br />Good luck!

 

[Sand Bass]

Re: 1994 225 Evinrude -proper set up

Dhadley, I am skeptical when purchasing a used prop (as you are). Maybe I do not have the prop I think I have? I bought this prop from an individual that has a boat slip at the marina where I launch. The prop does not say "raker" so I did not believe him at first. I took the prop to a local prop shop and asked why it was not stamped "raker" and the guy said it came off a volvo outdrive and is stamped (3855146) to identify the fact that it fits a volvo. He assured me it is a raker prop. He also said the prop is in excellent condition and never been worked on in any way (far as he can tell). The prop has no nicks or dings of any sort. Leading edges are perfect. On the outside of the hub it is stamped 3855146. I paid the shop $35 and they pressed in an OMC hub. Do I really have a true raker?

 

[Dhadley]

Re: 1994 225 Evinrude -proper set up

Yes thats a Raker for a Cobra SX. And yes the hub needed to be changed to fit your outboard. <br /><br />Whats your top speed at 5800? We can figure the slip % and see where where we're at now. Do you have a manual or hydraulic jack plate?<br /><br />Let us know!

 

[Jim@KSC]

Re: 1994 225 Evinrude -proper set up

Just butting in...<br /><br />There's a clue in your first post, sand bass. You said you had to trim all the way up (out).<br /><br />It really sound like you have too much lower unit in the water, especially for a raker, like dhadley indicated.<br /><br />If you don't have a jackplate, do you have remaining holes where you can raise the motor?

 

[Sand Bass]

Re: 1994 225 Evinrude -proper set up

I have a Rite Hite manual jack plate. It is easy to adjust. I assumed I was getting too high because when I am cruising (3k rpms) and hit the gas the prop will slip for a few seconds and then bite after boat has picked up speed. I will try lifting motor and see what happens. Hopefully I can pick up some rpms without getting too much slip or loosing bow lift. I will borrow a GPS this weekend to check true boat speed. I will post results.<br /><br />Thank You

 

[Dhadley]

Re: 1994 225 Evinrude -proper set up

OK thats not bad. It shouldnt slip for very long before biting, maybe a second. That leads us to believe it is still a true Raker. To expand on Jim's comment heres a very general rule of thumb we go by. If you can trim a motor out (positive trim) all the way and the prop still bites (does not ventilate) then you can (most likely) raise the X dimension. Many times the prop runs best when it starts to vent at near full positive trim. Again - this is a general rule of thumb and each rig may be slightly different. Each prop definately is. <br /><br />Its easy with your set up. Try raising the jackplate a 1/4" at a time. Or raise it more and work your way back down. Watch your water pressure. You have a good baseline now. When you test, write everything down. Even ride "feel". Trust nothing to memory. Always test with the same average load. Don't test in flat calm water if you normally run in 4' following seas. You get the idea. <br /><br />Good luck!

 

[Sand Bass]

Re: 1994 225 Evinrude -proper set up

I raised the motor about 1/2 inch. Went to the lake today. At wot motor did 6000 rpms (yea!). Boat speed was 68.6 mph (gps). I think the motor runs a little stronger in cool weather?? Water pressure was good. At wot I still had a little trim left but boat would start rocking and "fish tailing" (bad) if I trimmed up that last bit. I was by myself but carried some extra tools and gear to try and add some weight. At slow speeds motor cannot be above level (back of cavitation plate)or prop cavitates. The faster I go the more positive trim I can use without slippage. Once I get to 4000+ rpms I can use most all positive trim and prop will hold. I can control the slipping at low speeds just by keeping the trim level or a little below. The slipping during accelleration does not bother me...it gets the rpms up quickly like a powerband. Holeshot is great. The transom on this boat slants back so motor has a lot of negative trim when all the way down. Does this set up sound ok? <br /><br />Thanks

 

[Dhadley]

Re: 1994 225 Evinrude -proper set up

Sounds pretty darn good to me. Especially if you are happy with it. It souds like it starts to get loose at WOT. Cool, huh?<br /><br />Congrats!!

 

[Sand Bass]

Re: 1994 225 Evinrude -proper set up

Thanks for the help. I am happy with the performance of my boat. I just wanted to make sure the motor was happy. <br />Thanks again!