Hole Shot Disapeared?????

[the gaffer]

Hi, I have a Volvo Penta 5.0 GXI (270hp) on a Regal 1900, I bent a blade on the prop (a 14.5 x 19, 3 blade aluminum) so when I was looking for a new prop I was unable to test the RPM's etc as I did not have a working prop to test with. So I thought I would be safe to just go for something similar, I ordered and fitted a 4 blade Solas 14.25 x 19 and tested it at the weekend and have lost my hole shot completely,the stern bogs right down into the water and it takes for ever to get up on a plane, and that without towing anything or anyone?????? Any thoughts? I did have 2 more adults in the boat that last time, but still I was expecting similar performance. Once it eventually gets up on a plane 15-20 seconds, top end seems fine (50mph), but this is a 270hp 19 foot boat, it should be tearing ***** out of the hole, not sucking it!

Do you think I just chose the wrong prop, or is something more sinister going on?? I did not do anything else to the boat except change the prop??

 

[Kainon]

Re: Hole Shot Disapeared?????

I think you need to play with your trim position when starting off. and where the people stand/sit matters ( and how much they weigh, 150 or 350 ) Especially on a 19'.

THe 4 will give you more bite, should drop the WOT about 100-200 though speed may be slightly more.. You should have this moved to the prop section.

 

[Kainon]

Re: Hole Shot Disapeared?????

after post thoughts,

Double check the pitch, should be even numbered, 18, 20, 22. 3 blades usually run odd.

Also if the prop is cupped that will also effect, and Rake.. ( check out the prop section )

Go for a ride by yourself, and check the performance again and pay around with the trim position from a standing start, you dont always want full down at the start.

happy & safe boating.

 

[steelespike]

Re: Hole Shot Disapeared?????

Usually the Solas Amita 4 is very predictable. I would double check the size.Of it and your old prop perhaps the old prop was reworked to less pitch.
Perhaps a plug wire came off? You wouldn't be the first to not realize they were on 7 cylinders. Would think a 19 on that boat would over rev
easily.And come out of the hole pretty darn quick.You could get the old prop repaired and they could check the pitch.

 

[ExxWhy]

Re: Hole Shot Disapeared?????

I may be way off base on this, but I had a similar problem when I first switched to a Rubex 4 on my outboard powered boat. It came with a rubber ring that seals the gap where the exhaust escapes. Instructions were very vague as to whether my motor needed it or not. It seemed to me like it fit too tightly with it on, so I left it off. Result was massive exhaust venting over the prop which my boat never overcame with speed. Put the band on and it was a "what a dummy, operator error" moment for me. With the band on, it planes like never before and am very pleased with it.

So, in your case I am wondering if there is a similar band that needs to be installed? Since your boat is faster, it may overcome the venting with speed. But I have no idea if it is even through hub exhaust on yours. So this is just an uneducated guess, but the symptoms sounded similar.

 

[the gaffer]

Re: Hole Shot Disapeared?????

Hi, thanks for your resposes so far.

Exxwhy, I checked the box that the prop came in and there is no rubber ring or anything and so I swapped out the new one for the old one just to check how they sat up against the outdrive, they seem very similar and there does not seem to be any gap.

I just double checked my old prop and it was actually a 14.3 x 21, so dropping to the 19 pitch should have given me extra hole shot, not taken it away??

Checked the new one, defintely 14.25 x 19.

Will hopefully get out for a ride tomorrow to see if I can pin down any issues, but any more thoughts would be greatly appreciated.

The Gaffer

 

[steelespike]

Re: Hole Shot Disapeared?????

Maybe get the old prop repaired and compare it. Perhaps something else broke when
you dinged the prop?

 

[the gaffer]

Re: Hole Shot Disapeared?????

I thought that, but I had no real vibration in the boat which would suggest the shaft is not bent and I could (eventually) attain top speed.

Thanks

 

[steelespike]

Re: Hole Shot Disapeared?????

I'm thinking something other than drive system.damaged linkage Perhaps something
slipped when you yanked the throttle back.Or an untimley failure of some sort.
Only way to prove it isn't the new prop is to, run the original or borrow one like it.
You need to prove the prop is or isn't the cause.
If I hadn't wittnessed so many Solas 4 blade successes on here I wouldn't wonder if it was some other problem.

 

[the gaffer]

Re: Hole Shot Disapeared?????

Well for once I can expell a huge sigh of relief!!!!

Took the Regal out last night and it performed flawlessly, hole shot was very good, if not great, just 2 of us in the boat, so I guess it was all down to the weight and positioning of the weight in the boat last time out.

I just thought that the 270hp engine would be enough to overcome weight issues with raw power, especially on a relatively small boat, guess I was wrong!

Anyway for once I have solved a problem without costing me a dime, and as a bonus I get to leave the in laws at home when I go boating

Thanks for all your help guys.

 

[convergent]

Re: Hole Shot Disapeared?????

One other thing to look at is whether the prop is installed correctly. When I bought my boat a couple months back the seller had put on a new prop. I went out with him to test it and the holeshot was terrible. It would start to go and then rev up and not pull hard. It eventually got on plane and was fine, but it took a while. It turned out that the old thrust washer was dirty enough that he didn't see it and so ended up with the old and new washers in place. This created slippage, cavitation, or something. Once he found and fixed that, it was fine.