jake
Full Member
Posts: 25
Jeanneau Model: Sun Odyssey 35
Yacht Name: Sugar Mountain
Home Port: Gilford, NH
Country: USA
|
Post by jake on Jun 6, 2021 18:21:20 GMT
Hi all! I am new to this forum and have a question. I have a 2006 Sun Odyssey 35, and the motor feels sluggish. It starts right up, but only gets about 2 knots at 2500 rpm. Does this sound right? Any ideas? Thanks!
|
|
|
Post by Charlie-Bravo on Jun 6, 2021 18:47:28 GMT
Welcome to the forum, a good place with lots of help.
I also have a 2006 SO35, and your 2 knots isn't good, at 2500 rpm I would be making 5.5 to 6 knots with a fairly clean hull, revving to 3000 rpm + gives 7.5 knots but with a lot of noise and increased fuel consumption.
Quite a few possibilities, is she clean below the waterline? perhaps you have 'collected' some plastic tarp .. hanging off the keel bulb and acting as a sea anchor.
What prop have you? if feathering or folding perhaps it is stuck / jammed in the wrong position.
Does she sail faster? if so that should rule out the sea anchor and point to a propeller issue, could be a sheared key on the prop shaft, or perhaps the key wasn't installed so the prop is spinning a bit on the shaft, .
Perhaps ..... if all is well propeller wise, clutch slip could be the cause, but hope not.
Is it any quicker in astern?
Let us know what you find.
CB
|
|
|
Post by Don Reaves on Jun 6, 2021 19:20:12 GMT
I have a 2004 SO 35, and agree with everything Charlie-Bravo said. Also, check your prop for barnacles. They can make a very big difference.
|
|
jake
Full Member
Posts: 25
Jeanneau Model: Sun Odyssey 35
Yacht Name: Sugar Mountain
Home Port: Gilford, NH
Country: USA
|
Post by jake on Jun 6, 2021 20:34:07 GMT
Thanks for the response. It sails faster than it motors. Same sluggishness forward and reverse. The boat has always been in fresh water.
|
|
|
Post by Don Reaves on Jun 6, 2021 23:51:19 GMT
So if you're in fresh water, barnacles aren't the problem. Where are you located? I'm in the Great lakes, where Zebra mussels can cause the same type of problem, though in my experience, it's not as common.
|
|
|
Post by sailingabe41ds on Jun 7, 2021 0:13:42 GMT
Hi..
Any other history? Did the boat ever go beyond 2 knots? Is this something new? It would not be prop pitch problem if the boat went beyond 2 knots before and this is something new. Are you the original owner....was a survey done and all was fine till now? I put it in full throttle and see if the tach is working properly? I do not know what full rpm is on this Yanmar but if the tach reads 3300 to 3600 in you are not going anywhere then you know the engine and the tach is probably ok. Now you are left with a gear box problem or something with the prop/shaft. Talk to your diver who cleans the bottom and ask what it looks like down there... are all the blades there? Make sure your shaft is connected and nothing slipping down there....is the prop coming off....is it slipping from the shaft?
Love to hear outcome...
Best of Luck Abe
|
|
jake
Full Member
Posts: 25
Jeanneau Model: Sun Odyssey 35
Yacht Name: Sugar Mountain
Home Port: Gilford, NH
Country: USA
|
Post by jake on Jun 22, 2021 22:59:50 GMT
Update: the former owner used to get 5-6 knots at 2500 rpm. Dove down to inspect prop, no visible damage or debris interfering. Learned that the prop was removed at yard and fell off, likely not put back together properly. Boat is coming out this week to reset prop.
|
|
|
Post by Charlie-Bravo on Jun 23, 2021 9:31:36 GMT
Glad to hear you are closer to restoring the performance, if the yard in question couldn't bolt a prop on properly I hope you are in a different yard for the lift. Examine the taper on the shaft and prop with a critical eye, and have them both skimmed if the prop doesn't lock onto the shaft with a light shove, the prop spinning loose on the shaft just may have damaged the taper, and if it is, will cause the same problem for you again. Whilst it is out no doubt you will check the cutlass bearing/ anodes and sea cocks, then you can go and enjoy her confident that all is well below the waterline.
CB
|
|
|
Post by rene460 on Jun 23, 2021 12:27:02 GMT
Hi Jake, the propellor not being properly refitted would explain it. With a feathering prop, it is very easy to get the various gears aligned out of sync. It will not be the first or last time it happens.
The error will be a full gear tooth, so not a precision adjustment job. One tooth out make a noticeable difference in pitch that is quite easy to see. Also check that all three blades are at the same pitch, as a separate gear is used for each blade of the prop.
If you can get a manual from the prop manufacturers web site, it will have a procedure to follow, but nothing beats being there and looking to see that blades are at equal pitch to each other in both forward and reverse, and that overall the pitch looks reasonable. If they did not adjust the pitch adjustment screws, it will easily go into the right place. (If they did adjust those, it’s more complex and may need resetting on the bench to get the required pitch, but it is not necessary to adjust these to fit or remove the prop, so it should be ok.)
When you get back in the water, when you get into a suitable area, try the wide open throttle test, and record the boat speed you achieve for future reference. At wide open throttle you should achieve a little over the maximum rated rpm in the engine specification, not more that 10%. Increase the throttle gently as you should not exceed that 10% even if you are not yet at wide open throttle. A wide open throttle rpm of about 10% over max specified rpm indicates a prop well matched to the engine.
Reaching the specified max rpm plus 10% before wide open throttle suggests too little pitch, while not achieving that rpm indicates too much pitch. This is the test my Yanmar mechanic advised me when I put the feathering prop on my boat.
rene460
|
|
jake
Full Member
Posts: 25
Jeanneau Model: Sun Odyssey 35
Yacht Name: Sugar Mountain
Home Port: Gilford, NH
Country: USA
|
Post by jake on Jun 24, 2021 21:27:02 GMT
Thanks to you all for the great input. The prop was removed and reset yesterday, and today we got 5-6 knots at 2500 rpm! It's like a new boat! So the prop was removed and re-installed with incorrect gear settings, and the pitch was incorrect. I now have get used to driving a boat with more speed, both forward and reverse!
Btw, Fred Hutchison from Max Prop was very helpful and knowledgeable. I recommend contacting him with Max Prop issues.
Happy sailing!😁
|
|
|
Post by Don Reaves on Jun 25, 2021 0:07:11 GMT
I’m glad you sorted it out. It’s always nice to hear when someone has success with a problem like that.
|
|
|
Post by rene460 on Jun 25, 2021 11:23:41 GMT
Hi Jake, good to know it was sorted out. Frustrating, but not the first or last time it will happen to someone.
Still worth recording that max wide open throttle and corresponding boat speed, as a base line for future reference.
rene460
|
|