prop advice experience

[ian parkes]

I recently bought a Valiant 490 with a suzuki DF70 .
I have no experience of other boats so can only go by gut feel and advice , but I think the engine will pull a 19" prop instead of the existing 17".
This seems to be the opinion of the cornish ribbers but not having had time to actually test with a gps revs for speed etc or get anyone else to drive the boat I can't be sure .
All I can say is the feel of the boat and the way it accellerates it feels like it could be bit low geared . Peak revs are about 6000 but haven't taken an exact note .
The prop I have fitted is a 13 1/4 x 17 13 spline .

What Iam looking for is iether a secondhand 13 1/4 x 19 prop or a loan prop .
It could be an expensive mistake to order a new prop if its not what i need
if Any one who has the same set up could advise me then I would be grateful.

Also any info of what props are the same spline would help .

[Nos4r2]

You're definitely overrevving-max rpm should be 5800 (I googled your engine)
The link below might help.

http://www.boatinglife.com/product.j...873C13?ID=3444

Did the previous user do a lot of skiing or tow toys?

[Mollers]

Originally Posted by Nos4r2

You're definitely overrevving-max rpm should be 5800 (I googled your engine)
The link below might help.

http://www.boatinglife.com/product.j...873C13?ID=3444

Did the previous user do a lot of skiing or tow toys?

It was a diveboat Nosser, nuff said.

[ian parkes]

Originally Posted by Mollers

It was a diveboat Nosser, nuff said.

The owner used it a bit for diving but, as I understand it was only for him and his wife , I don't think it was a dedicated dive boat carrying loads of divers , its not big enough , the rack would only carry 4 cylinders and with only approx 60 hrs use ??

Maybe it was specced as a dive boat , who knows but I have got to try it out with a GPS and check the revs properly .
As i have just said to Roy making it pull a higher ratio would make the slow speed handling more difficult in rough water as the engine could be labouring ?? Just my feelings

[Nos4r2]

In my (limited) experience, with the max pitch prop on mine possible it becomes awkward in tall waves (7'+).The engine laboured and wouldn't plane unless I surfed down them 1st but in normal weather it went like a rocket.It took pretty extreme conditions to create a problem though- wind against tide blowing force 7-8 in Old Harry tide race.

Most of that was because I couldn't get the searider flooding hull to drain though so in theory you should be ok as long as you're within manufacturers recommended WOT rpms.


I'm not 100% sure this is correct-someone call me a tosser if I'm wrong!

[ian parkes]

Well what you are saying sounds reasonable to me and also goes along with what I felt in a following swell at the weekend .
Its all very well gearing the boat up to go like hell on flat water and cruise well at low rpm but if that makes the trip home a nightmare when it blows up rough then Ill leave it as it is .
I have been told by a suzuki dealer that my 17 pitch prop is standard on a DF70 and a valiant dealer also said they send them out with standard prop. so I aint panicking to get one this week , just incase we go to Scilly again

[ADS]

Lets see some pics of the new boat Parksey, I did after all find it!

[randski]

[ian parkes]

Originally Posted by ADS

Lets see some pics of the new boat Parksey, I did after all find it!

Oh well done Bob , you are a star mate .

And thanks ADS if I had been 10 mins later getting to this I would have lost it , if you get down here come for a trip and the drinks are on me , been too busy loving the boat to post here lately .

[ian parkes]

oh and that smooth suzuki better then any 2 stroke coughing death out the back awaiting its final total loss stroke.
Sorry 2 stroke owners remarks made for the benefit of a fellow cornishman who has insulted our Suzuki's once too often .