Poor hole shot/on plane time - 115 on nitro x5

[jrhea]

Hello -

I have a nitro X5 (17ft) with a 115HP optimax engine on it. That is the largest engine allowed on the boat. I currently have a 22p Turbo II (3 blade) on it and the hole shot is very slow when I am loaded with more than one person and water in the live well. What can I do to improve the speed that I get up on plane? My prop vents are wide open and it still seems to be bogging down. I have owned the boat for 2 years and it has done this during the time I have owned it, but I am now getting fed up enough to ask.

It runs great once it gets on plane - about 50mph. On plane speed is more of a priority than top end.

Suggestions? lower pitch prop, maybe replace spark plugs/do a fuel service? raise engine?

John

[jrhea]

Here are some pictures of my prop. There is a bit of "nick" taken out of one of the blades. Not sure if that is enough to affect performance.

[Smalliefan2]

I have a Ranger, with 115 E -tec. I use a 23x13.5 Power tech three blade. P to P is about 3.5 - 4". Comes out of the hole well, not too much bow rise. Tried from 18 to 21 pitch with various plugs and jackplate heights. That works for me. Top end is 48 on gps.

[JR19]

Do you know your wide open throttle rpm's? Do you have a jackplate? Do you have a water pressure gauge and if yes how much PSI at wide open throttle?

The reason I ask those questions is if you have room in your upper rpm range AND strong water pressure you can raise your motor height with a jackplate. "Typically" the higher you go the easier it spins up on holeshot...however there comes a time when you get too high and it effects your top end by gaining rpms and losing speed due to prop slip, plus your water pressure can get weak. Finding correct motor height can sometime be a tedious job because once you get near the sweet spot that's best for all around performance moving the motor up/down .25" can make a noticable difference.

If you can tune your motor height then do it...I would definitely send that prop to Mark Croxton and have him repair it. When you fill out a repair slip on his website you need to include information such as current max rpm. If your wanting him to "work" the prop to help with performance in an area (ie:holeshot) include what you looking for in the repair notes.

First and foremost I would ensure my motor is healthy. If it runs like a scalded dog on top end and purrs like a kitten at idle more than likely your good and your slow holeshot is a set up issue. I have one other suggestion for holeshot but I will save it for after you fine tune your motor height (if you have a jackplate) and after you get your prop repaired/tweaked...and Mark Croxton is the ONLY person I would let touch that prop.

here is a link to his repair service...http://www.marksprops.com/

[jrhea]

JR19 -

I am going to go out to the lake this weekend and get the answers to your questions. I do not have a jackplate (that is movable). My motor screws into the transom on a bracket and is about in the middle of the bracket. I would have to make new holes in the transom to move it.

The motor runs like a scalded dog and purrs like a kitten.. no issues starting ever.. runs amazing.

If I send to him to get repaired, what tweaking would you recommend? Do you think the current damage on the prop is enough to hurt the hole shot performance?

John

[jrhea]

Also forgot to mention, it has a SE Sport 300 Hydrofoil on it that the previous owner installed.

Thanks for all the help!

John

[Savage]

Your prop is not in good shape, and needs repaired badly.....if you want top performance.

[JR19]

JR19 -

I am going to go out to the lake this weekend and get the answers to your questions. I do not have a jackplate (that is movable). My motor screws into the transom on a bracket and is about in the middle of the bracket. I would have to make new holes in the transom to move it.

The motor runs like a scalded dog and purrs like a kitten.. no issues starting ever.. runs amazing.

If I send to him to get repaired, what tweaking would you recommend? Do you think the current damage on the prop is enough to hurt the hole shot performance?

John

Also forgot to mention, it has a SE Sport 300 Hydrofoil on it that the previous owner installed.

Thanks for all the help!

John

When you say "I do not have a jackplate (that is movable)." I am going to assume you have what's called a static set back plate...which sets the motor back like a jack plate but it is not adjustable up/down. if you wanted you could unblt the motor and raise it a hole on the motor mount if you can. if my memory is correct most motors have 4 holes on the motor mount. You can rise the motor but it will require unbolting it and re-attaching it. I would do that only as my last option but just wanted you to know it is an option. Sorry if it seems like I am asking a ton of questions but fine tuning motor height has a ton of variables, so hence a ton of questions is what I may ask...what is your current prop to pad? Here is picture that gives a simple explanation on how to measure prop to pad height...

As for your prop yes it needs repair but I have seen a lot worse but it does need attention ASAP. In my first reply I said I had a suggestion I would hold off on until other things were address but you unknowingly mentioned it in reply#6 and that is a hydrofoil. If you have a foil and you're still struggling out of the hole then something is way off. Report back with WOT rpm and prop to pad height and we will go from there.

[jrhea]

My prop to pad is 4". There is one more hole that I could raise my motor up on the back plate.

John

[duckband417]

See what your WOT RPMS are. I would definetly get that prop worked on. If it’s “bogging down” trying to get on plane and you aren’t near your rev limiter on that motor I would say drop down a pitch size. I would bet 99% of your problem is your prop, getting reworked. Have your numbers available though. What RPM the boat breaks over, max RPM at WOT.

[JR19]

My prop to pad is 4". There is one more hole that I could raise my motor up on the back plate.

John

Now we are getting somewhere...I think you could benefit by going up one hole. "typically" (and I will use the word typically losely) a prop to pad of 3.5" is a good starting point. Some boats actually run above the pad and some like to be in the 2" range but "most" bass boats are in the 3-3.5" range. The higher you go the more freely it spins up but remember what I said about motor height in reply#4...before adjusting motor height you must have a water pressure gauge. I would like to know wot rpm, GPS speed (NOT SPEEDOMETER) but gps speed and water pressure at WOT. Even with that being known you still need to get that prop repaired. Having a foil you should pop right of the hole as it is but obviously something is off a tad. I suspect it a combination of bad prop and a tad low on the prop to pad is what's hurting your holeshot.

[jrhea]

Thanks guys!! I am going out tomorrow and will get readings on WOT and water pressure.

When you say prop "worked" does that mean shaped to a lower pitch, or what? I get repairing the nick on it.

John

[Nova Kaw 650]

I have the same engine.
Lots of lost performance in a dinged up prop.
Prepare to switch to a 21" or even a 20", probably a Laser II.
Exactly what are the RPM'S when it's trying to break over on plane? If it's not over 3500 and the prop vents are unplugged, then go to a lower pitch.

[jrhea]

Just as an update for everyone. I went to the lake today troubleshooting and used the "3500" RPM target for launch in the hole. Well, I was at almost 5000. So I realized that I had all the Vents open and was causing excessive prop slip. I bought some plugs and sealed them up and I am at about 3200 RPM now and come out of the hole much quicker.

Thank you all for the help!

John

[Nova Kaw 650]

Just as an update for everyone. I went to the lake today troubleshooting and used the "3500" RPM target for launch in the hole. Well, I was at almost 5000. So I realized that I had all the Vents open and was causing excessive prop slip. I bought some plugs and sealed them up and I am at about 3200 RPM now and come out of the hole much quicker.

Thank you all for the help!

John

[Savage]

Your prop still needs fixed though.

[Nova Kaw 650]

Your prop still needs fixed though.

X2, you could be leaving MPH on the table, and it might be creating a vibration that could be harmful to the driveline.

[JR19]

Glad you got it fixed through prop vents...out of curiosity what was your max rpms and gps speed at wide open throttle. The reason I ask is you still need to get hat prop repaired and pending speed/rpm you might want to get it worked or re-pitched.

[jrhea]

I was at 5800 RPM and 48 GPS. And it is a 115 mercury optimax pro XS.

John

[Nova Kaw 650]

I was at 5800 RPM and 48 GPS. And it is a 115 mercury optimax pro XS.

John

That's a lot of slip for a 22" prop. Get the prop fixed.