Prop Size/ Engine Rebuild or Repower ?

Ex Hobie Sailor · **Posted:** 15 Mar 2020 06:43

Had a question what size prop Tartan 37 owners with W-33 Westerbeke are running. I have a 3-Blade Maxi Prop 18RH set to 20 deg pitch as recommended by PYI.

I can cruise 6K maybe 6.25 in calm water. I cannot reach top RPM @3000, can only reach @2700 and exhaust comes out black. Not black smoke, but unburned fuel ? Otherwise engine running fine, starts right up, runs like a red swiss watch. I reduced the pitch to 18 deg two years ago, my cruise dropped to under 6K, and still could not reach top rpm and there was black exhaust. The other issue is I recently installed new shaft/strut/cutlas.l Shaft was cut at threads (threadeds cut short) to fit Maxi Prop, not sure if another prop will have enough thread ? Considered a Martek 3 blade folding prop, but had Maxi refurbished last year at PYI

I was seriously considering a repower with Beta 38, met with Beta dealer, he said my engine could use an overhaul for sure, it burns a quart every 10 hrs, has some leakage at rear main seal, but at 2250 hrs has a lot of life in it. He said it was just broken in and was a thing of beauty. He said just add oil, if it becomes hard to start or burns more oil than a rebuild or repower is in order. He said most likely engine was run to charge batteries and cylinder walls are glazed, another issue he brought up is the over propping, lugging the engine ng, but said i was ok as long as exhaust not black. I also have a friend with Sabre 28 withe W-33, said he used a lot of oil also, I also saw another blogger saying his W-33 used used a Qt every 10 hrs. Maybe this is normal for this engine ? Another question, is this, was trying to save me $$ or does he makes more on
rebuild ? He seemed like a really honest guy, not pushing anything.
I like new, but still paying off the boat...2 more years to go.

Any thoughts ?

puffcard · **Posted:** 16 Mar 2020 17:02

I'd say you likely have an Mitsubishi S4L2 block. There are a ton of parts available on eBay, was a very common block used in all sorts of forklifts, CAT mini-excavator, Toro Groundmaster, etc. I just saw a brand new complete long block for $5k. But if yours is running, I would rebuild it. The parts are very cheap, and available. The kits $500, shop $750-$1500. Rebuild fuel pump and injectors, another $500. If you can take it out, just pay the machine shop to break it down and rebuild it. Need to look on the head by the injectors of the "S4L" stamping. Using a qt every 10hrs is not normal, wasn't that way when new...right.

Ex Hobie Sailor · **Posted:** 27 Mar 2020 14:20

Hello Puff Card,
Good advice on the rebuild. I am 5th or 6th owner, this has been the normal as long as I have owned her. Leakage from either Rear Main Seal or Oil Pan Gasket is contributing to oil consumption. BTW, measured prop, it is a 16" 3 blade Maxi Prop. I'm resetting the pitch ratio to 16 deg, and going to get a laser tach to check the actual crankshaft rpm this season. I found some notations from PO that tach was off, usually reading higher than actual RPM.

Ex Hobie Sailor · **Posted:** 20 Mar 2021 19:34

Repowered with Beta 38 last September 2020, out with the old...in with the new !

puffcard · **Posted:** 21 Mar 2021 19:27

Love the Beta, we went with the 35hp, same engine block. The 38hp just turns a little faster. If you are long distance cruising or thinking about it. It's the right move, for confidence.

madmike · **Joined:** 06 Sep 2020 10:08 **Posts:** 111

What propeller and pitch are you using with the Beta engines?

#162 came with a Beta 38 and 3-blade Max Prop. We're wondering if the previous owner got the right settings on the propeller.

puffcard · **Posted:** 22 Apr 2021 14:44

For reference, we installed a new prop two years ago. Went with the Flexofold 17-11-3B RH. We repowered few years ago with the Beta 35, rated 2,800 and have the Hurth transmission, that has a 2.14:1 ratio. I think I could of gone with touch more pitch. I ran over-pitched with the W50 for years and got use to it.

ekern · **Joined:** 22 Oct 2006 17:21 **Posts:** 14

Contemplating changing from 25-year-old "Classic" MaxProp 2-blade 16 RH to new "Easy" MaxProp 3-blade on Condor #419 also with a 1982 W33, rebuilt in 2004 and then installed in 2018 and now with about 600 hours on it. Did you keep the oversized 18" MaxProp? Any guidance?

madmike · **Joined:** 06 Sep 2020 10:08 **Posts:** 111

We bought our boat with a Beta 38 and 17" MaxProp Classic 3 blade set at 18 degrees. That worked great. Except we abused it by hitting a submerged object. We sent it back to PYI (they are really helpful and easy to work with) and they replaced the blades and refurbished the hub. The new blades are 16" which PYI recommended setting to 20 degrees. This also works great.

Refurbishing the Classic prop was a bit cheaper than replacing it with a brand new Easy.

Besides avoiding underwater rigid obstacles, PYI's advice to us for longevity was to (1) grease the prop every 6 months with scuba gear, and (2) be gentle: wait 5 seconds in neutral when switching between forward and reverse.

Tartan37.com

Prop Size/ Engine Rebuild or Repower ?

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