Rybo Runner Rebuild

[Spencer]

Hey Billfish what size shaft did you go with I am about to order a bracket for mine and I think I will need the 30". I need to know to get the correct measurments for the bracket any info would be great. Thanks

Rob

[BILLFISHS]

I WENT WITH THE 25" SHAFT THE BOAT DOES GOOD THE DUSKY GUYS SAID THEY WERE GOING TO 30" SHAFT THEY ALSO SAID IT WAS BECAUSE THE WAY THE SUZUKI PUSHED WATER UP IN FRONT OF THE MOTOR NOW WITH THIS BEING SAID MY ENGINES ARE MOUNTED IN THE BOTTOM HOLES WE TRIED THE NEXT ONE UP BUT MOVED THEM TO THE BOTTOM AND IT RUNS GREAT THERE WITH LITTLE WATER PROBLEM PUSHING UP BUT IT DEPENDS WHERE THE BRACKET IS MOUNTED ON THE BOAT I DONT KNOW HOW WE CAN FIGURE OUT WHERE MINE IS MOUNTED WE SHOULD TRY TO DO THIS OVER THE PHONE THAT WAY ITS REAL TIME AND EASIER TO MEASURE.

[Braingears]

I was searching google and came across these forums.
We have the Rybo Runner 31 molds. Once we saw the boat and molds, we knew that it would be PERFECT for us. We currently manufacture the Simplicity Marine Drives which is a surface piercing drive. Since surface piercing is designed to have half of the prop out of the water while on a plane, we have no problems dealing with the air bubles and don't have any problems with cavitation.
I currently own Break Water Boats, and I was considering calling it "Breakwater 31"

[MarkV]

A friend recommended the forum and we have been reading about your Rybo repower/rebuild with interest. We are sorry to have come to the party so late. We would love to know how the project turned out.

We have had our '83 Rybo (hull #6) since the early 1990's and performed a similar project to yours (Spencer) in early 2002 - Our OMC's w/Seadrives were tired... and 'cockeyed'. We had Cal and Cliff install their fiberglass bracket which, among other things, raised the boat about 2-3". Like your boat, our transom was in great shape. Also, we chose to keep our Pannish Controls - they are the best -

We repowered with Yamaha 250 Saltwater series EFI's - 30" shafts. When in the raised position, the engines are completely out of the water (we discussed this with Cal & Cliff prior to the repower, as we get alot of growth in our area). Our boat has a full tower and a single 200 gal tank. in flat conditions w/light winds we get the following speeds and fuel consumptions:

3700rpm=32mph@24gph=1.33mpg
4100rpm=34mph@27gph=1.26mpg

I would say on an average day out we are getting just over 1 mpg.

We would be most interested in hearing from anyone who has repowered with either 2 or 4 stroke 300 hp OB's to hear about rpm/cruise speed/w/o throttle and fuel burns at the different rates and any other experiences - good or bad.

We have learned quite a bit about our boat in the time we have had her, and would be happy to let anyone know anything they would like - including comments on the "boxes" and what we did with them. In the meanwhile, here are a couple of recent shots of our boat (yes it is the original gel coat) that still turns heads 26 years after coming out of the box...

[fishfighter]

I would like to see some close up pictures of the trunk cabin. The link that was posted is not working anymore.

I been thinking of chopping up a Wellcraft 2900 Sportbridge to a center console,leaving in the twin 350's. I would still like to have a place for out of the weather for overnight trips and that trunk cabin might be the trick.

Thanks

[sth]

I have owned my Rybo since 2001. I installed Yamaha Saltwater 250's on a Stainless Marine bracket. Boat ran great but always had cooling issues. I put new nose cones on for low water pickup and that helped. Motors finally got tired and last year I repowered with 275 Verado's. I could not be happier. No cooling issues and the boat flys. I keep the boat in the water full time and it tops out at 47 knots with full tower and fuel. Yesterday the fuel burn at 30 knots was 12 per side, 19 at 36 knots. The best thing about the motors is they are so quiet I can have a normal conversation even at wide open throttle. At the dock you cannot hear the engines running.
Do not plug the vents. One of the things I tried to improve the Yamaha cooling problem was plugging the vents. It did not help, cost about 10 knots on the top end and added a rough vibration to the ride. They were still plugged when I put the Verado's on and first time out with the new motors I overheated. I had the vents unplugged, the cooling issues were cured and the smooth ride returned. I also added about 12 knots top end.

[Bligh]

I have owned my Rybo since 2001. I installed Yamaha Saltwater 250's on a Stainless Marine bracket. Boat ran great but always had cooling issues. I put new nose cones on for low water pickup and that helped. Motors finally got tired and last year I repowered with 275 Verado's. I could not be happier. No cooling issues and the boat flys. I keep the boat in the water full time and it tops out at 47 knots with full tower and fuel. Yesterday the fuel burn at 30 knots was 12 per side, 19 at 36 knots. The best thing about the motors is they are so quiet I can have a normal conversation even at wide open throttle. At the dock you cannot hear the engines running.
Do not plug the vents. One of the things I tried to improve the Yamaha cooling problem was plugging the vents. It did not help, cost about 10 knots on the top end and added a rough vibration to the ride. They were still plugged when I put the Verado's on and first time out with the new motors I overheated. I had the vents unplugged, the cooling issues were cured and the smooth ride returned. I also added about 12 knots top end.

You are basicly saying that the steps should be left to fill with water at rest and empty at speed? And this cures overheating outboards and allows the boat to go 10 knts faster over a boat with those vents closed in on the steps? I have always watched most people modifying their rybo runners and dont most close in the vents? I also believe one boat company somewhat took the steps out and renamed the boat? Are you saying just leave them alone?

[sth]

My best guess is that the vents draw air under the hull when running which relieves a suction effect created by the steps. Releasing the suction caused the smoother ride and faster speed. I had originally thought that this excess air might be causing the motors to draw in water with too much air in it to cool the motors. That is why I tried plugging them. I now think the over-heating problem is more dependant on the engine choice.
My Yamaha's were always a problem. First I tried a jackplate to get them lower and farther from the hull. Did not help. Then I bought new nose cones with low water pickups from Bob's Mackine Shop in Florida. That helped alot but did not cure the problem if I was running hard. When I lost reverse in one of the engines I decided to replace them rather than repair them.
With the hull vents open I have no problem with the Verado's overheating even at WOT. I do not know exactly why they run cooler than the Yamaha's did but the water pickups are located low on the nose cones.
Hope this explanation helps.

[Spencer]

What length shafts are the Verados?

[sth]

Verado shafts are 30's