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#1
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posted to rec.boats.cruising
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Hi Roger and everyone who replied!
Thanks so much for the constructive feedback! Couple of points to clarify: - I forgot to mention, the gear ratio is about 1:2.06 (can't read the label on the gearbox) - I recently had the bottom done completely - it is as smooth as it gets. - I also had the propeller checked by the manufacturer and they confirmed that the pitch is what it has been manufactured at. - I have a brand new shaft and coupler and these are properly connected. So, I guess my best bet is to check the transmission. Now, how do I do that? - Can I check the clutch/transmission without disassembling everything? Any ideas? - Can I check and repair the transmission without hauling the boat out of the water? - I also notice that there is a very high pitch noise from the engine after about 3700rpm until the max. rpm. Could that also indicate a toasted transmission? Thanks again! Dennis |
#2
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posted to rec.boats.cruising
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By process of elimination, it pretty much has to be something
slipping. That high pitched noise suggests a clutch. It could be as simple as the shift cables being misadjusted so the clutch isn't fully engaged. Unfortunately, if that is true, the transmission is probably going to have to come out of the boat because the clutch surfaces are glazed. First thing to check: Cable adjustment for full travel on the lever at the transmission. If cable adjustment fixes the problem, the transmission is still probably on borrowed time. Don't depend on it in a tight spot. Next: What RPM do you get in reverse? Marine transmissions usually have two clutches and the reverse one is unlikely to be damaged. If maximum RPM in reverse is significantly less than when bringing it up to full power in forward, the engine is being loaded up more. That probably means the forward clutch is slipping. This test is hard on the engine so just do it once and with a well warmed up engine. You can buy or rent tachs that read a little bit of reflective foil taped to a shaft. Check engine RPM at the flywheel to be sure the tach is right. Then check the tach against shaft RPM. If you verify slipping, be sure the key is still in the shaft coupling before you pull the transmisson out of the boat. Shaftlines have been put together before with the key missing. The set screws can wear a groove around the shaft so it won't back out and feels tight to the hand but the shaft will slip in the coupling. A mark or piece of tape on the shaft will reveal this pretty quickly. A missing key on the prop could also be overlooked since the taper will keep the prop tight and turning until it is heavily loaded. That could also make your high pitched noise. -- Roger Long "Dennis" wrote in message ups.com... Hi Roger and everyone who replied! Thanks so much for the constructive feedback! Couple of points to clarify: - I forgot to mention, the gear ratio is about 1:2.06 (can't read the label on the gearbox) - I recently had the bottom done completely - it is as smooth as it gets. - I also had the propeller checked by the manufacturer and they confirmed that the pitch is what it has been manufactured at. - I have a brand new shaft and coupler and these are properly connected. So, I guess my best bet is to check the transmission. Now, how do I do that? - Can I check the clutch/transmission without disassembling everything? Any ideas? - Can I check and repair the transmission without hauling the boat out of the water? - I also notice that there is a very high pitch noise from the engine after about 3700rpm until the max. rpm. Could that also indicate a toasted transmission? Thanks again! Dennis |
#3
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posted to rec.boats.cruising
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![]() Dennis wrote: Hi Roger and everyone who replied! Thanks so much for the constructive feedback! Couple of points to clarify: - I forgot to mention, the gear ratio is about 1:2.06 (can't read the I think your gear ratio should be closer to at least 3.0. Your transmission sounds like it is configured for a planing power boat. Sherwin D. label on the gearbox) - I recently had the bottom done completely - it is as smooth as it gets. - I also had the propeller checked by the manufacturer and they confirmed that the pitch is what it has been manufactured at. - I have a brand new shaft and coupler and these are properly connected. So, I guess my best bet is to check the transmission. Now, how do I do that? - Can I check the clutch/transmission without disassembling everything? Any ideas? - Can I check and repair the transmission without hauling the boat out of the water? - I also notice that there is a very high pitch noise from the engine after about 3700rpm until the max. rpm. Could that also indicate a toasted transmission? Thanks again! Dennis |
#4
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"sherwindu" wrote
I think your gear ratio should be closer to at least 3.0. Your transmission sounds like it is configured for a planing power boat. No, that's a fairly typical reduction for a sailboat. The greater the reduction, the larger the prop. Sailboats usually compromise effeciency under power with smaller reduction ratios and props in order to reduce drag under sail. -- Roger Long |
#5
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posted to rec.boats.cruising
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The analogy with an outboard may not carry over to an inboard, but on my
sailboat there is a distinctive improvement in performance using a 'pusher' type engine gearing. Most outboards that do specify their use on sailboats usually have gear ratios 3.0 or higher. The best pusher I ever used was my British Seagull 6 bladed prop with a gear ratio of about 4:1, and I saw pictures of this engine pushing huge heavy barges. Roger Long wrote: "sherwindu" wrote I think your gear ratio should be closer to at least 3.0. Your transmission sounds like it is configured for a planing power boat. No, that's a fairly typical reduction for a sailboat. The greater the reduction, the larger the prop. Sailboats usually compromise effeciency under power with smaller reduction ratios and props in order to reduce drag under sail. -- Roger Long |
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