I just bought a 26C with a Westerbeke 30B Three and a JS transmission. I know it has a 2 blade folder as I saw it during the survey, but I won’t know what make until I haul it out in about a month.
In any case, there is a big CLUNK when going into gear. Fwd or reverse. I hope it is the blades of the prop flipping out and not the transmission.
Is this normal? I have sailed for decades with a Hallberg-Rassy and a fixed 3 blade and never heard anything going into gear.
Chancy has a Flex o Fold 2 blade prop and there is a distinctive clunk when it begins to spin. I find it quite reassuring. There is a substantial plastic bumper for the blade.
A test. When you are at the dock tied off put in gear - forward (you should hear your clunk ) give it a few seconds. - put in neutral. Give it a few seconds - Put it back in gear. If you hear a clunk again - it may be the transmision. (Because all this test is with the boat not moving. The prop should stay in its set position for going forward. And if its prop Clunk the clunk should be much less or not at all. )Transmision clunk like that could be damper plate abuse from PO.
Good luck. Let us know.
My engine is a Westerbeke 35-D3, 31HP. I’m guessing its similar to your 30B. My manual also says idle of 1000-1200 RPM. But I just started my engine and checked, and it idles nicely at 650 RPM, and no clunk with my folding prop. I’m with Joe, 1000 RPM is way too high.
I get a distinct bump sound when shifting into gear at about 600 rpm, no desernable sound to the opening of the the Gori two blade… But I think that the engine sound and vibration would mask that event
After reading this string I contacted the BETA dealer and asked for his comments. I heave a 30 with BETA 25 and Seaprop.
Current idle speed is 900rpm (900-950 is spec.)
Reduction is a little more than 2-1.
There is a clunk when the blades deploy but not alarming and the clunk is in the prop not the gearbox (I tested it at the dock and there was no clunk).
The dealer said that I would be fine dropping the rpm to 800-850 provided there is no roughness in the idle.
If it is the Martec prop, this could be the two blade , non geared folding prop. The blades move independently. When the shaft stops the blades will swing wherever they want and the top blade flops down to the closed position. Bottom one hangs down (unless you are sailing fast enough to lift it). Put the transmission in forward and this top blade snaps up and goes clunk.
Going into reverse the blades are opened by centrifugal force and the clunk is less if you are at low idle. In reverse with normal rpms this prop didn’t work very well and I guessed it’s because the blades would partly close up.