New motor(vetus) does not rev up to the max!

[Jani-SRI]

Seatrial done...lift up planned for later today.


About 2050rpm-2100rpm when boat is moving freely. So after the pump adjustment, same 100 increasement as without load.

Boat barely broke the 6KTS speed....



By the way... When the propeller was installed, it was moving freely and not touching to anywhere.... The blades were also opening well.

[hoppy]

Originally Posted by Jani-SRI

I read from the flexofold manual, that it is ok to even replace the propeller under water, but then the screws should be ordered from flexofold with pre- applied tread lock. The normal tread lock does not cure under water they say..

You need Loctite 248

LOCTITE 248 - Threadlocker medium strength - non-drip - Loctite

[unclemack]

Pressing the prop hub forward as hard as you can while turning it to simulate the thrust of the prop in forward gear might be useful as a quick first check.
Obvious signs of interference/rubbing might exist but might not be visible without removing the prop.
Check for a tiny bit of fore-and-aft movement which will be there if backlash is present - there's supposed to be some.

Plasti-gage is a useful product for checking clearances between internal parts in an assembly with no access for direct measurement.

Worth having the alignment of engine and drive mountings checked too.

Best to get a decent engineer to check everything for you if you can.

However you lock the threads be sure not to void Flexofold's warranty.

[Badsanta]

Get a portable Lazer tachometer to check your RPMs your tach may be off. I found one on ebay for $20 works great.

[Mike Banks]

Maybe the blades are opening too far? See if there is an adjustable stop, or a screw adjustment that limits the pitch. How big is this boat anyway? Mine is 42 foot long and a 30 hp Yanmar at 3000rpm gets it up to about eight knots if the hull is clean. My propeller is not a folding type though. This is a small diesel engine designed to rev--so one has to let it rev. I think your problem is is propeller related.

[Jani-SRI]

No adjustment for the blades on the flexofold. When it is fully open then it is fully open. IT should be fully open when in action.


So....today the boat was lifted up from the water. Hull looked clean, prop had slightly growth. The propeller was correct size 18x14-3L. There was no need to disassemble anything. The numbers were clearly visible on the side of the blades. The prop. was turning freely and there was good gap from the leg zinc anode. I pushed but there is no any movement. So there is no problems with the washer or anything causing friction.
The technician wondered how small the prop. actually looks....

--> The prop. was cleaned, boat was put back to the water and tested again.
...This time the engine rev max to about 2300rpm and the boat speed increased to around 7.5 - 7.6kts. So good improvement, but I am not happy yet. Not until I see the close to hull speed 8.2 knots or the rpm close to 3000rpm.


I asked if I could turn the engine to confirm the real ratio in the gear...but the technician did not see any point in that and was not super eager to assist. BUT... as I explained at earlier, there is a stamp of 2.15 on the SB side of the gear box.... I have checked the PS side as well and there is a type plate with all the info. It says 2.15 there as well. I think it should be safe to believe this is correct. It would really has to be someone real dumb ass to fit SO wrong gears inside of the housing that I think it is not really even plausible.....no..not even from Italians as someone suggested?






So.... the adjusting of the pump helped quite a lot. Because when the propeller was new, the engine revved to 2000 while on the way, now 300rpm more...
Tomorrow have a talk with Vetus rep. again and then we have to talk what to do next.

[TurninTurtle]

One other (oddball) place to look....

Same exhaust outlet as the old engine used?

You can limit an engine's power by exhaust back-pressure. We used to use just a variable exhaust baffle for throttle on RC models.

[Cadence]

Originally Posted by Jani-SRI

No adjustment for the blades on the flexofold. When it is fully open then it is fully open. IT should be fully open when in action.


So....today the boat was lifted up from the water. Hull looked clean, prop had slightly growth. The propeller was correct size 18x14-3L. There was no need to disassemble anything. The numbers were clearly visible on the side of the blades. The prop. was turning freely and there was good gap from the leg zinc anode. I pushed but there is no any movement. So there is no problems with the washer or anything causing friction.
The technician wondered how small the prop. actually looks....

--> The prop. was cleaned, boat was put back to the water and tested again.
...This time the engine rev max to about 2300rpm and the boat speed increased to around 7.5 - 7.6kts. So good improvement, but I am not happy yet. Not until I see the close to hull speed 8.2 knots or the rpm close to 3000rpm.


I asked if I could turn the engine to confirm the real ratio in the gear...but the technician did not see any point in that and was not super eager to assist. BUT... as I explained at earlier, there is a stamp of 2.15 on the SB side of the gear box.... I have checked the PS side as well and there is a type plate with all the info. It says 2.15 there as well. I think it should be safe to believe this is correct. It would really has to be someone real dumb ass to fit SO wrong gears inside of the housing that I think it is not really even plausible.....no..not even from Italians as someone suggested?






So.... the adjusting of the pump helped quite a lot. Because when the propeller was new, the engine revved to 2000 while on the way, now 300rpm more...
Tomorrow have a talk with Vetus rep. again and then we have to talk what to do next.

Maybe you are just not going the get the 13 X the squire root of you water line length. That is a broad estimate

Keep us posted.

[Badsanta]

Thanks for the updates.

[Jani-SRI]

Originally Posted by TurninTurtle

One other (oddball) place to look....

Same exhaust outlet as the old engine used?

You can limit an engine's power by exhaust back-pressure. We used to use just a variable exhaust baffle for throttle on RC models.

Same Same.... The outlet is pretty big though... diameter might be even bigger than from the engine. The waterlock is same as well... Volvo with stainless ends and rubber body. That should be ok for 65hp says volvo if I remember correct.



Normally I would get a tachometer, but I am here in France and everything seems to be extremely difficult in here. IF I would order one, then I need to have address and the marina people are looking me quite bad already when I ordered some stuff earlier... And I cannot find any shop. I would not like to use 80e or so because the ball is now pushed to Vetus. If they want to check they can check. The pump adjustment helped a bit, so I think the whole problem got to be engine related. The technician was not REAL vetus tech and he was quite carefull with his moves...So maybe just need to adjust the pump some more...?