Bad cavitation on hole shot!!!

[1FASTLASER]

Re: Bad cavitation on hole shot!!!

No problem. If memory serves me right the medium plugs will get you the desired result. I just chose to feather the throttle because of varying load conditions.
Mark..... That was the best most precise explanation I think I have read on PVS venting on hole shot. That should be stickied .

 

[Texasmark]

Re: Bad cavitation on hole shot!!!

No problem. If memory serves me right the medium plugs will get you the desired result. I just chose to feather the throttle because of varying load conditions.
Mark..... That was the best most precise explanation I think I have read on PVS venting on hole shot. That should be stickied .

Thank you sir. Having been there done that (BTDT) on a personal basis I have spent some time on the subject. My first ported prop just happened to be a Laser back in '89. It had a round hole of about 3/8" on a 13+ dia/21P prop. I had a Ranger BB with a 115 Tower. The prop was an experience all it's own. Sometimes I would just get up and down just to listen to the engine, the prop beating the water (I liked to run with the trim out to the point where speed would fall and rpms would start to increase). You could hear the engine singing (6k is where she ran) and the prop beating, then feel the lockup where the rpms would drop and the speed would increase. Everything was stock.

What I really liked about it was as said, I could enjoy my BB top end yet get up on a slalom.

Mark

 

[brandon6.0]

Re: Bad cavitation on hole shot!!!

Ordered some medium pvs plugs but they don't fit. My prop is a quicksilver laser 2. Checked and its a 1992 model original to the boat. It has the square pvs plug holes. Couldn't find any plugs for this prop. But did read about people filling them in with marine JB weld. Your thoughts.

 

[1FASTLASER]

Re: Bad cavitation on hole shot!!!

Brandon have you tried feathering the throttle. By that I mean the next time out pay close attention to when the prop beaks loose. Just before she breaks loose you back of the throttle and the boat if all else is set should drop her nose. At that point you should b able to nail it again and she should launch like a rocket. That is unless the prop does in fact have to much ventilation. I have always had good luck with a prop on bass boats that does in fact break loose a little just as the boat starts to nose over. It doesn't take a lot of negative throttle to offset the ventilation. On my Procraft V180 which like I stated is the sister to yours with a XR6 would set you back when using this method. I do wish I could remember props haft height but thats been almost 20 yrs ago. Hmmmm sure do miss her she fished great and gave ALOT if boats a fit trying to catch me.

 

[Texasmark]

Re: Bad cavitation on hole shot!!!

Send an email to Merc customer service. They make the prop, they make the plugs (or have them made). For a lot of boats the open squares are too big and as I said your rpms will go out of sight before you ever get going. Only certain boats need holes that large and I don't kno what kinds of boats those are. Since I had a Laser and it had 5/16 to 3/8 round holes, and since BBs have gotten bigger and heavier, I'd guess that the bigger mils need the bigger holes. You can epoxy them closed, but there you will loose the benefit of the prop with small holes. I guarantee you if you get your plugs and tune them right you will be amazed at what they can do for you just like I said.

Mark

 

[brandon6.0]

Re: Bad cavitation on hole shot!!!

Well they would have to be custom made. Thinkimma give it a shot and close them in. Thin maybe drill them back out as needed.

1 fast laser I have tried feathering the throttle and such. I can actually control it if I back the throttle off and get it on plane. But would love to have a decent and fast hole shot. I think it's worth a try.

 

[Texasmark]

Re: Bad cavitation on hole shot!!!

Well they would have to be custom made. Thinkimma give it a shot and close them in. Thin maybe drill them back out as needed.

1 fast laser I have tried feathering the throttle and such. I can actually control it if I back the throttle off and get it on plane. But would love to have a decent and fast hole shot. I think it's worth a try.

Feathering the throttle reduces the exhaust pressure/volume, unlike WOT firewall to get out of the hole. Obviously with less exhaust gas you have more water over the prop and get more thrust.

Just for grins and to prove a point, why don't you epoxy them closed as you said to get a data point, or better yet, get a thin piece of metal and some RTV and cut little patches to cover the holes with enough lap for glueing, placing them on the outside of the prop.

You'll know the first time you hit it where you are and will also know if closing them completely off is the right answer so it doesn't matter if they come off after the first shoot. But if one comes off take all of them off to keep the thrust balanced.

Then, if closure is the right answer epoxy them up without the metal covers.

Mark

 

[brandon6.0]

Re: Bad cavitation on hole shot!!!

Ok will do thanks mark

 

[brandon6.0]

Re: Bad cavitation on hole shot!!!

Ok update.

Filled holes in with marine JB weld. This thing rips straight out the hole. Can full throttle it from a dead stop and it just runs up on plane like a rocket. Worked perfect. Do u think its worth possibly drilling them out just a tad to see how it does? Would there be any side effects to them being fully closed at all times? Acted like it drank a lil more gas to me. Your thoughts?

 

[Texasmark]

Re: Bad cavitation on hole shot!!!

Man I can't believe you . Go away. You make no sense!!!!!!!!!!!!!!!!!!!!!!!!!!

Mark

 

[brandon6.0]

Re: Bad cavitation on hole shot!!!

Thanks mark! Finally enjoying it. Thanks a lot!

 

[Texasmark]

Re: Bad cavitation on hole shot!!!

Thanks mark! Finally enjoying it. Thanks a lot!

That's what I read in your last response......that you are perfectly satisfied, and then you come back with that "stupid" (and I seldom if ever think questions are stupid) question about whether or not you should drill them out somewhat.

Glad you stayed focused and didn't get distracted by other responses and got your right answer.

Mark