Author Topic: need prop advise (Read 20711 times)

Wesley Ellet · « **Reply #40 on:** March 11, 2016, 04:49:56 PM »

Ya I noticed that flat pad on your boat. I race RC boats and my first boat back in 89 had that same configuration, shallow V with a flat pad. It would outrun all the others on calm water. Had em all beat at the internats till the third day. It got windy and I couldnt keep it right side up.

V153 · « **Reply #41 on:** March 11, 2016, 05:41:55 PM »

Guess I should've mentioned my Lightspeed was hammered on a lil by the boys at Burris propeller ...

David CVX-16 · « **Reply #42 on:** March 11, 2016, 06:42:16 PM »

Quote from: Wesley Ellet on March 11, 2016, 04:39:40 PM

Any idea what speed I can expect with the 20 raker?

If your 20" Raker runs 5,500 to 5,700 RPM, I would try a 22" Raker to get the RPM's down to about 5,400 to 5,500. These outboards have their top horse power rated at 5,000 RPM.

Hyperacme · « **Reply #43 on:** March 11, 2016, 07:10:12 PM »

" Any idea what speed I can expect with the 20 raker ? "

I would guess 50 mph ... + or -

V153 · « **Reply #44 on:** March 11, 2016, 07:40:54 PM »

I wouldn't increase pitch if it ran 5700 flat out with a 20. That's about perfect.

Raise the motor a hole or two first.

V153 · « **Reply #45 on:** March 11, 2016, 07:47:32 PM »

Quote from: Hyperacme on March 11, 2016, 07:10:12 PM

" Any idea what speed I can expect with the 20 raker ? "

I would guess 50 mph ... + or -

Ya. Mebbe a lil better, pendin on load?

thedeuceman · « **Reply #46 on:** March 11, 2016, 08:18:36 PM »

I run a 20" raker on a 75 GT-150 with A 73 115 hp Johnson. With everything out of the boat I can just tic 50 at about 5300 RPM.
The hull does have quite a hook in it, and it sticks in the water petty good.

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Mrs.TheDeuceMan · « **Reply #47 on:** March 12, 2016, 11:11:07 AM »

Quote from: thedeuceman on March 11, 2016, 08:18:36 PM

I run a 20" raker on a 75 GT-150 with A 73 115 hp Johnson. With everything out of the boat I can just tic 50 at about 5300 RPM.
The hull does have quite a hook in it, and it sticks in the water petty good.

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And he REALLY means EVERYTHING! ;-p

David CVX-16 · « **Reply #48 on:** March 12, 2016, 06:01:07 PM »

Joe needs a boat trailer.

Fuzzbutt · « **Reply #49 on:** March 13, 2016, 12:11:26 AM »

I've got a near mint 22" raker and have run it out to 5500 rpm at 56 mph in my cvx16. Nice enough prop but out of the hole it's not too fun and the torque steer and it's propensity to make my hull hook in high speed turns isn't ideal. I personally would look for an OMC SST and if they made a 21" get that one. I'd run that before I dropped a lot into a Raker. I can run my 19" with 150 pounds in my boat plus my 230 pound behind out to 54.6 and I still have a immediate on plane holeshot. And mine had an encounter with a rock at a ramp and has been refined by yours truly. Maybe the 20" Raker may be better but the 22 is sensitive in my opinion.

I wouldn't worry about the rpm too much. Too high is always better than too low. My 100 hp Johnson saw as high as 6200 more than a few times. I know my 140 has hit that. I don't think I'd run it that fast for hours on end but for a couple miles it's no big deal.

As said above run only premium. It's more expensive but it's cheaper than a $2000 rebuild. Most expensive oil you can mix at 50:1 also. I'd also spray an entire can of BRP's engine tune stuff (decarb) in your motor following the directions on the can. That really woke up my old motor.

Get your motor up on your transom. The highest you still have good water pressure and good steering control with is the fastest.

I really like my '79 140. Yeah they are old but they are pretty easy to maintain.

Oh and I like Champion QL77JC4 spark plugs. Get them at Rock Auto or at some auto shops like O'Rileys occasionally have them in the back for under $3 each.

We like pics. Helps a lot figuring out your setup too. Good luck.

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V153 · « **Reply #50 on:** March 13, 2016, 01:31:11 PM »

Quote from: David CVX-16 on March 12, 2016, 06:01:07 PM

Joe needs a boat trailer.

Joe needs a cargo trailer ...

V153 · « **Reply #51 on:** March 13, 2016, 01:46:34 PM »

I swear I had her doin 51 last year Joe ...

V153 · « **Reply #52 on:** March 13, 2016, 01:50:00 PM »

Like Fuzz said: Run the surface gap plugs. I experimented with all sorts of plugs but those seem to work best.

thedeuceman · « **Reply #53 on:** March 13, 2016, 02:18:06 PM »

Quote from: V153 on March 13, 2016, 01:46:34 PM

I swear I had her doin 51 last year Joe ...

Yea... Yer skinnier than me

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David CVX-16 · « **Reply #54 on:** March 13, 2016, 03:35:24 PM »

Yes, the Rakers have a lot of torque to them, but I have the no feed back (NFB) Teleflex steering system, and can take my hands off the steering wheel at speed without the steering wheel turning. The SST's come in odd pitches, and the Rakers in even pitches.

My reason for perhaps going to a 22 Raker is more speed. I tested a 20 and a 22 Raker on the same day, and the 22 Raker was faster at about 400 RPM's less, and still within range at about 5,400 RPM's. I attribute this to the fact that the maximum HP on my 1985 115 HP Johnson is developed at 5,000 RPM according to the owners manual. Why have the engine turn faster then necessary?

Only on the water testing of your boat and motor will answer questions you have.

I went to the trouble of buying and testing 3 SRX's, 5 Rakers, two types of SST's, a Lightspeed, and a OMC 2- blade bronze prop. I have my answers, but they may not be the same for you. All I can do is to give you my various prop results and observations. Good luck.

http://www.classicglastron.com/phpbb/viewtopic.php?f=103&t=8603

Hyperacme · « **Reply #55 on:** March 13, 2016, 03:54:10 PM »

" Only on the water testing of your boat and motor will answer questions you have. "

Best to test all chooses (props) on same day for set up's top speeds, weather, temps, water conditions can have an effect on speeds.
Torque steer, bow lift, stern lift & general feel also factor into "Your" best prop.

I would lift your motor (as far as your steering set up will allow) before even starting prop testing ...

84carlson · « **Reply #56 on:** March 13, 2016, 10:34:14 PM »

Well I got it in the water today, never had a boat in the water in March before. All this talk bout props got me interested in more speed, my 19" Apollo only gets about 49 mph, so I took Dave's advise and ordered a 22" Raker on E bay...Suppose to be new, got them down to $220.00. Not ready to raise the motor, but curious if I can get over the 50 mark. With my 84 -140 I used to hit 55 with a 19" sst all day.

Now its time for the Baystar steering...

Hyperacme · « **Reply #57 on:** March 14, 2016, 05:36:15 AM »

With the BayStar steering you can lift your motor without any Clarence problems

David CVX-16 · « **Reply #58 on:** March 14, 2016, 06:54:58 AM »

The 22 Raker should work. Your RPM's should be around 5,400 with a light load. The Rakers lift the bow. My boat likes the motor trimmed all the way back.

84carlson · « **Reply #59 on:** March 28, 2016, 02:32:18 PM »

Got the Raker in last week, took it out today, full fuel and lot of stuff in the boat and the over weight driver 53 mph on the GPS great bow lift and overall a great little prop. I'm sure I could pick up a little more speed if I empty out a lot of the junk. Boat speedometer was off by 2 mph..

Now I need to get the steering don, next project....