1986 EBBTIDE 180 Riveria Cobra 4.3L OEM Propeller???

[gamparano]

New owner am looking to find the OEM size and pitch for this boat. Have the Boat's User guide, but the page I need is missing. The propeller that came with boat is a 15.5x13. WOT is about 3800-3900. Get up to about 30-35 mphs, kts ?.Does anyone know the recommended Manufactuers WOT. Also I have been reading the threads and I seem to find that 4.3L 1985-86 boats on here are running 19 pitch props (?????). Also read that the WOT on 4.3L is between 4000 and 4200. Need some guidance on what I need to check to get it right. The engine has been serviced running great. have a reliable mechanic, he does do the work, but I have to take the boat to him 72 miles.

 

[steelespike]

Re: 1986 EBBTIDE 180 Riveria Cobra 4.3L OEM Propeller???

Are you sure of the prop size? 13" pitch? not diameter?It is something you might find on a pontoon or other hard to push boat.
With the 13 your rpm should be off the scale.
3800/3900 is about what you might run for cruising does the motor sound like its cruising?
If its really turning 3900 at wot you have a serious motor/ drive line problem.
I've seen 4.3s run 23" props and also seen them over rev with a 19. Unless the Ebbtide is a real slug you should be running around 50 mph.with about a 21 -23" prop.
To go 35 mph with a 13" prop the motor would have to be turning 5300 rpm.ouch!
Are you measuring knots or mph? Is it gps speed?

 

[gamparano]

Re: 1986 EBBTIDE 180 Riveria Cobra 4.3L OEM Propeller???

You were correct it. I had it wrong. The prop should be a 14 1/4 x 17. It was written on the serivce manual by the previous owner as the recommended prop. But there is nothing on the prop identifying as 14 1/4 X 17 .Got a new prop 15 x 17 and ran it. WOT was 3900, but the engine seemed to be reving way above that. The engine runs smooth, no missing, when idling. Oil pressusure good. Tach sits between 600 and 800 RPM when idling in neutral. uSE 89 Octane as recommended. When pushing throttle climbs rite up so spuutering, missing runs rie up. No stalling at shifting, gears are smooth. Can some help identify the OEM range pitch for this engine.