Prop pitch

Natterjack

Natterjack

Member
Joined
29 Dec 2011
Messages
41
Location
Isle of Wight
www.dibbensremovals.co.uk
Our Volvo MD2030 C won't go above 2,400 - 2,500rpm in gear, I assumed this was due to lack of power/fuel so checked/replaced various items (Recon Injectors/Lift pump/Fuel hose/Filters all replaced fuel tank cleaned, Exh. Elbow, Exh. & Back pressure checked).

Since launching last year (after buying Kylema 2) the max rpm have dropped to around 2,100 rpm, which I guess is due to some fouling of hull/prop.
It also now stalls or labours on 'tick over' when fwd or rev is engaged.

Kylem 2 is a Dolphin 31 - Lwl 8.1m, Beam 3.15m, Displacement 5,000 - 5,500kgs
Gear reduction is 2.3:1 - Prop is a Darglow Featherstream 15" Dia/11.5" pitch

Is it possible for the pitch or gear ratio to be so far out? I would appreciate any advice or thoughts!!!
 
I am not able to help unfortunately but bumping this thread up may get you a reply. You seem to have gone through a lot already.
 
Last edited:
Kylema 2 said:
Our Volvo MD2030 C won't go above 2,400 - 2,500rpm in gear, I assumed this was due to lack of power/fuel so checked/replaced various items (Recon Injectors/Lift pump/Fuel hose/Filters all replaced fuel tank cleaned, Exh. Elbow, Exh. & Back pressure checked).

Since launching last year (after buying Kylema 2) the max rpm have dropped to around 2,100 rpm, which I guess is due to some fouling of hull/prop.
It also now stalls or labours on 'tick over' when fwd or rev is engaged.

Kylem 2 is a Dolphin 31 - Lwl 8.1m, Beam 3.15m, Displacement 5,000 - 5,500kgs
Gear reduction is 2.3:1 - Prop is a Darglow Featherstream 15" Dia/11.5" pitch

Is it possible for the pitch or gear ratio to be so far out? I would appreciate any advice or thoughts!!!
Click to expand...

Dont guess--go to clementsmarine.co.uk and speak with their man, they will want to know the dimensions more or less how youve already noted them, and will give you all the information you require. They are widely used here in Essex and have a very good reputation. Hope you sort it. N
 
I have MD2030D, reverse gear 2.35:1 and 2-blade fixed propeller 16X11 and can achieve easily 3500rpm maximum (according to specs). Ignoring the boat size (I have LWL 9,44m, beam 3.80m, displ. 6.000kg+) your propeller size doesn't look so wrong to be able to achieve only 2500rpm max. Is the reverse gear working OK?
 
Kylema 2 said:
Our Volvo MD2030 C won't go above 2,400 - 2,500rpm in gear, I assumed this was due to lack of power/fuel so checked/replaced various items (Recon Injectors/Lift pump/Fuel hose/Filters all replaced fuel tank cleaned, Exh. Elbow, Exh. & Back pressure checked).

Since launching last year (after buying Kylema 2) the max rpm have dropped to around 2,100 rpm, which I guess is due to some fouling of hull/prop.
It also now stalls or labours on 'tick over' when fwd or rev is engaged.

Kylem 2 is a Dolphin 31 - Lwl 8.1m, Beam 3.15m, Displacement 5,000 - 5,500kgs
Gear reduction is 2.3:1 - Prop is a Darglow Featherstream 15" Dia/11.5" pitch

Is it possible for the pitch or gear ratio to be so far out? I would appreciate any advice or thoughts!!!
Click to expand...

Prop size is probably correct, although Featherstream usually set pitch in degrees. It is adjustable - forward and reverse independently. The symptoms of stalling and not reaching full revs could be engine related or a too steeply pitched prop.

Suggest you get Darglow to check that the pitch is correct and that the prop is operating correctly.
 
You say that the boat hasn't been out of the water for 2 years. From the symptoms, I suspect that you may have a heavily fouled prop. A couple of years back, we sailed from Barcelonna at the start of the season without being lifted out, the engine would not rev above 2,200 as opposed to a 'normal' max of nearer to 2,800 and the problem just got worse. I dived under the boat and found the prop was covered with barnacles and worm casing; 15 minutes work with a scrapper solved the problem. Might be worth checking the current state of your prop!
 
Here on sunny east coast we are blessed with masses of mud particles suspended in the water, failing to keep the prop clean after 3 months afloat was enough to take our max revs down from 3500rpm to 2000rpm, with huge clouds of black smoke ! up on the scrubbing posts the prop was solid with baby barnacles , a quick clean off and back to normal. Luckily we took the advice of Mike French ( French Marine Motors ) before scrapping the engine in disgust after spending £100s on cutless bearing, injector servicing , new filters etc.
Give it a look it could save you loads !!!
 
Nostrodamus said:
So is anti fouling the prop worth it?
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Really depends on your situation. Conventional antifouling is usually ineffective. It does not stick well and the very act of using the prop as a propeller (ie whizzing round at 1000RPM+) wears it off pretty quickly. There are various specialised coatings on the market including lanolin based goops that some peole use with varying success. However, not every location has a barnacle fouling problem - so if you don't get fouling, don't bother. If you do, then the remedies are either try the preventative methods, or regularly scrub by drying out or diving.
 
Thanks everyone for you words of wisdom!

I may be wrong, the pitch could be in degrees?

I did contacted Darglow some time ago and they suggested the propeller size/pitch matches Volvos recommendation and I therefore should look at other possible causes. So on that advice looked at the engine replacing bits and even getting a Volvo mechanic to have a good look, he couldn’t find what’s wrong and suggested changing prop (i.e. over propped)

Unfortunately our featherstream is an early model which cannot be adjusted easily (pitch stops can be re-machined but needs to be sent back ££££)

FYI when she was launched last year (clean prop etc) the max RPMs of 2,500 achieved around 6-7+kts - according to log, @2,200 around 6kts.

NEVER had lots of black smoke, which is what I'd expect from an overloaded engine... on the overhand If the engine was lacking power it wouldn't achieve 6-7kts would it?? is my thinking right?
 
Thanks everyone for you replies, I did post last night but I'm still waiting for moderators approval!?! Hopefully it will appear soon!!
Dan

p.s. How long do I have to be a member before I can post instantly, without waiting for the moderators to approve every post???

It makes it impossible to start or be part of a thread if it take up to 24hrs to appear, by which time the post is on page 2 !!
 
Posted On behalf of Kylema 2

Thanks everyone for your replies, I did post last night but I'm still waiting for moderators approval!?! Hopefully it will appear soon!!
Dan

p.s. How long do I have to be a member before I can post instantly, without waiting for the moderators to approve every post???

It makes it impossible to start or be part of a thread if it take up to 24hrs to appear (If at all), by which time the post is on page 2 !!

Cheers, Dan (Kylema 2)
 
Kylema 2 said:
Thanks everyone for you words of wisdom!

I may be wrong, the pitch could be in degrees?

I did contacted Darglow some time ago and they suggested the propeller size/pitch matches Volvos recommendation and I therefore should look at other possible causes. So on that advice looked at the engine replacing bits and even getting a Volvo mechanic to have a good look, he couldn’t find what’s wrong and suggested changing prop (i.e. over propped)

Unfortunately our featherstream is an early model which cannot be adjusted easily (pitch stops can be re-machined but needs to be sent back ££££)

FYI when she was launched last year (clean prop etc) the max RPMs of 2,500 achieved around 6-7+kts - according to log, @2,200 around 6kts.

NEVER had lots of black smoke, which is what I'd expect from an overloaded engine... on the overhand If the engine was lacking power it wouldn't achieve 6-7kts would it?? is my thinking right?
Click to expand...

Bump - so reply has a chance to be seen!
 
The fall off in revs is probably fouled prop. The speed is correct for that power/prop size (if your measurement is accurate). That leaves one thing - check the rev counter. A 2030 certainly lets you know if it is labouring as it will if you are only really running at those revs and that speed. Check the revs with an independent counter.
 
Tranona,

Kylema 2 says engine labours or stalls when put in gear, so I can't see what rev counter has to do with the problem.


Kylema 2,

I suggest you check that you can rotate the shaft by hand when the gearbox is in neutral. If you cannot, then most likely that something is round the prop or growth on shaft or even a shaft gland too tight.
 
Tranona - Agreed the drop off in rev's and some speed is probably due to fouling of prop/hull

I will check the engine idle speed is correct independently (I have temporarily adjusted it to 950 - 1,000 rpm according to the volvo tacho, and it doesn’t stall or labour anymore) and then due some proper speed/rpm checks over several runs.

Oldsalt - I can move prop shaft easily by hand but I intend to have her lifted & cleaned soon anyway.

Thanks, Dan
 
theoldsalt said:
Tranona,

Kylema 2 says engine labours or stalls when put in gear, so I can't see what rev counter has to do with the problem.
Click to expand...

But he also says he gets good speed without the usual symptoms of over propping. If the prop (or fouling) was holding the engine back you would expect lots of black smoke. When playing around - sorry carrying out controlled tests - with my 2030 discovered it is pretty obvious when there is serious overpropping to the extent that it won't rev above 2600 (out of 3600). If the engine is running happily then it suggests it is actually revving higher than indicated.
 
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