Ribcraft 585/150 Evinrude prop size help! - Page 2

JABS · 11 April 2008, 09:18

Cavitated with the engine trimmed well in.

Hightower · 11 April 2008, 20:02

Quote:

Originally Posted by JABS

Cavitated with the engine trimmed well in.

Could be the outboards too high, but lowering it won't solve your lack of RPM or speed.

JABS · 13 April 2008, 15:40

Yes, Andy, we did wonder if the outboard was too high. I intend to photograph and talk to Ribcraft.

GPS fixed over the weekend but the hail prooved too much. Yes, fair wather ribbers!

Downhilldai · 16 April 2008, 00:22

Who rigged it?
Have you been back to them about your problems?

Neil Harvey · 28 April 2008, 19:13

Is it fixed yet??

JABS · 28 April 2008, 21:22

No!!!

The 1 pitch prop that was kindly lent to me was the wromng fitting.

We have tested with the 21 and on a very calm Solent got 4400rpm ad 41 knots. I still think there is more there!!!

I still think I need to try a 19 or 20 pitch prop, so am looking out!

The delay was due to bad weath and then a faulty GPS!

Cheers Neil.

Hightower · 28 April 2008, 21:47

I recon that you're just about there performance wise.

Biggles Ribcraft with the 140 Suz on the back never went past 41 knotts and my 6.2 Vipermax was 42 knotts reving at 4500 rpm with a 21" prop when she was rigged light and now is 39 knotts at about 4900rpm with a more normal load and one crew member with a 19" prop.

If you do find a cause of your low performance I certainly would like to hear from you as I was sure that my Rig was underperforming too.

Neil Harvey · 30 April 2008, 17:37

Quote:

Originally Posted by JABS

Could the Tacho be out??

Tony

Yep. I just got the engine report from the service on mine, and it shows my revs maxing at 5741rpm.
Now, the tacho was registering 6400 which is why I went to a 21" prop. However, on moving up to the 21", I appeared to lose speed, which did not seem correct given the engine is now peaking rev wise (according to the tacho) at 5800 ish, which is peak power output.

But, it appears the tacho is out, so it was in the right rev range in the first place, and I was getting a couple of knots higher top end. So, the 19" will be going back on

Tony, if you want to borrow it before it goes back on, no probs. I a thinking about being out tomorrow and Saturday if the weather is not too horrendous both days. But after that, the 19" will be back on the boat

That 21" sure was an expensive spare

Neil

JABS · 30 April 2008, 18:25

Thanks to everyone.

My next action is to run the engine with the test lead and the Evoinrude diagnoatic software to ceck th tacho.

Other than that, maybe I am there.

Hightower · 30 April 2008, 19:15

Quote:

Originally Posted by JABS

Thanks to everyone.

My next action is to run the engine with the test lead and the Evoinrude diagnoatic software to ceck th tacho.

Other than that, maybe I am there.

Have you bought this off ebay? I'd be interested in if this works and how easy it is to use if that's OK

JABS · 30 April 2008, 21:50

Quote:

Originally Posted by Hightower

Have you bought this off ebay? I'd be interested in if this works and how easy it is to use if that's OK

Yes, looks OK. Haven't hooked it up yet. All the guy has done is to make up a lead and put the software on a CD.

I need to buy a USB to serial converter because I don't have a serial port on the laptop.

If you want to try it, let me know. You can borrow it with pleasure.

Hightower · 30 April 2008, 21:54

Might be handy for the future, thanks Tony.