08 2100 with 08 300xs no power out of hole

[karzrus]

Trying to post a pic.

 

[12pack]

I'd remount the motor on the jackplate up 2" so that the prop shaft is even with the pad at the top of the travel that's how my boat came set up from Roberts Marine.

I find I don't use the very bottom of the travel of my jackplate anyway as having the prop 5" down when starting out or tubing is too low. I do all my starts with the prop about 3 -4" below the pad and raise it from there as the boat accelerates. That's also about where I set it for tubing. So I think you are too low if you do your starts with the jackplate all the way down as you will be about 7" below the pad at your current set up.

I hope my discriprition of my modification to the jackplate made sense, as you will also benefit by removing the bottom 4-5 " of flat area that drags in the water.

Maybe you have a motor issue too, but you still have these two set up issues to clear up IMO.

You are right on the height, I believe I'm 2-2.5" below the pad all the way up. Although I'm mounted all the way up on the motor and on the Jack plate. I understand what you are saying about removing the bottom rear of the plate, could I get some pictures 406-490-0480. I could also build a plate that would cover the bottom of the setback on the transom. My boat is back at the shop they are going to check the reeds and make sure a sleeve hasn't twisted.

 

[12pack]

I was able to view your photo from the link on my email! Just what I had in mind, nice job!

 

[ForbesZ]

Not sure if this has been done or is just a dumb suggestion, but is there any chance the motor is starved for fuel on launch? If there's an internal flap of rubber loose inside the squeeze bulb or flap of something stuck in the fuel filter or something like a piece of cling wrap in the gas tank, maybe when there's a sudden change in fuel GPM that "thing" is moving around and partially restricting fuel flow. If anything is not letting the motor take exactly the amount of fuel it wants exactly when it wants it, I'd think that would result in poor hole shot. Perhaps try a portable gas can with brand new length of 3/8" gas line shoved in the top and connect that to the motor with no bulb or nothing in the line. Then get a buddy to hold on to the gas can while you punch down the throttle. If it still does the same thing then it's likely the fuel delivery system is fine, but if the thing shoots out of the hold like never before then I'd be changing the lines, filters, and cleaning out the tank.

 

[12pack]

Not sure if this has been done or is just a dumb suggestion, but is there any chance the motor is starved for fuel on launch? If there's an internal flap of rubber loose inside the squeeze bulb or flap of something stuck in the fuel filter or something like a piece of cling wrap in the gas tank, maybe when there's a sudden change in fuel GPM that "thing" is moving around and partially restricting fuel flow. If anything is not letting the motor take exactly the amount of fuel it wants exactly when it wants it, I'd think that would result in poor hole shot. Perhaps try a portable gas can with brand new length of 3/8" gas line shoved in the top and connect that to the motor with no bulb or nothing in the line. Then get a buddy to hold on to the gas can while you punch down the throttle. If it still does the same thing then it's likely the fuel delivery system is fine, but if the thing shoots out of the hold like never before then I'd be changing the lines, filters, and cleaning out the tank.

Thanks that's a good idea trying a test can, fuel psi has been tested but not under a load.

 

[skynet]

How's your top end speed? Are you able to hit the rev limiter?

 

[12pack]

With 25 trophy plus like 78 gps the boat would go faster if I could drive it, I can't remember the rpm but was nowhere close to the limiter. We tried a 21p 3 blade prop that was on the shelf at the shop just to see and it hit the limiter at 57 gps.

 

[ForbesZ]

Thanks that's a good idea trying a test can, fuel psi has been tested but not under a load.

Fuel pressure and fuel flow are related but kinda separate. You can have good PSI but still have low GPM. But it seems you know that because you said PSI has been tested but not under load (and PSI will drop under load if GPM is restricted/too low). The fact that you can hit the rev limiter with the 23 prop suggests the GPM overall is satisfactory, but when you're WOT you tend to get there with a more gradual increase from low to high GPM (whereas punching it out of the hole you need the fuel flow to increase from low to high GPM almost instantly). Since pumps tend to push better than they pull, and the pump is in the motor not the tank (meaning it's trying to pull the fuel up) I'm thinking something like a loose flap of rubber inside the squeeze ball could get sucked across the line when you punch it but not when you creep up to WOT.

Just a thought ...

 

[kushog]

Sure sounds like a motor issue. I have run a 30" Mercury Pro-Max prop on mine and my daily prop is a 28" Solas Scorpion that runs like a 30.5" and the boat will plane with 4-5 people in it. It's no drag boat with that tall a wheel on it but planes just the same with no drama.

 

[Sam I am]

I agree with the consensus that your motor is too deep. Raise that bad boy up and see what happens...I think your performance across the board will go up AND it will get easier to drive.

 

[ForbesZ]

I agree with the consensus that your motor is too deep. Raise that bad boy up and see what happens...I think your performance across the board will go up AND it will get easier to drive.

Yes, it sounds to me like the motor is too deep as well but I don't think that's the only issue. I run a 25" Trophy Plus on my 2000 BRX with 250 ProXS/1.75 pretty much all the time and don't have any significant issues with hole shot even with the prop shaft all the way down on my hyd. jack plate (which puts me about 4" below pad). If the op's boat is a long deck then he's got less weight and more HP than I do so he shouldn't have a problem with the 25" Trophy Plus. In fact just yesterday I was pulling three 10-12 year old kids on a Super Mable 3-seater tube behind the boat while having 5 people on board and 3/4 tank of fuel. To keep it from porpoising I always pull tubes with the jp all the way down and trimmed all the way under and it came out of the hole okay with the 25" wheel. It was somewhat sluggish but not that bad considering the weights - there was about 240 lbs on the tube and about 800 lbs of people in the boat.

 

[12pack]

Not sure how to raise my motor without getting a static setback bracket, which I don't really want more setback since main use of the boat is watersports. My motor is mounted in top hole and jp is mounted in top position on transom plate...

 

[ForbesZ]

Not sure how to raise my motor without getting a static setback bracket, which I don't really want more setback since main use of the boat is watersports. My motor is mounted in top hole and jp is mounted in top position on transom plate...

http://checkmate-boats.com/forums/showthread.php?t=30827&page=15

Check out the pictures on posts 149 and 150. This custom made offset bracket adds basically no setback and he has a 400R bolted to it.

 

[Sam I am]

Not sure how to raise my motor without getting a static setback bracket, which I don't really want more setback since main use of the boat is watersports. My motor is mounted in top hole and jp is mounted in top position on transom plate...

Just want to make sure I understand this correctly: if you're engine is mounted in the top hole, it's actually mounted at the deepest setting. If that's the case...mount your motor on the middle hole. That will get you a couple inches right there. Based on what you stated earlier that will get you up to even with the pad I think.

Here's a pic of a 250 Pro XS on a bass boat w/plate. It's mounted the middle hole. My G2 is not on the top hole either and I can jack my motor well above the "pad" (Starliners don't have a pad..it's the bottom of the V)

http://thmarine.com/atlas-hydraulic-jack-plate#!prettyPhoto[media_gallery]/3

Edit: sounds like a motor issue, but my thoght is to eliminate any and all possible set up issues. If you can't get the motor above the pad, that will really affect your top speed. I was amazed at how much difference a couple inches made on my hole shot with my Merc. It was literally the difference between go and no-go.

 

[12pack]

Motor is mounted in the bottom holes, high as it can be mounted with what I've got. Reeds all checked out good today.

 

[Sam I am]

Man, I hope this thing gets figured out for you...have you had the cylinders scoped and all that?

 

[12pack]

Not quite sure what scoped is but mechanic has had Port side head off to replace o-rings when he got bad leak down numbers. Port side head was replaced prior to me getting the boat, I believe it was because they had bad leak down test also. He is pulling both heads tomorrow to make sure a sleeve hasn't twisted. Thanks for all the help guys. If we don't get anything figured before I get back home I'll try the fuel can test and hopefully get you out on it Sam so you can see what you think.

 

[Sam I am]

I hear ya. A guy posted on FB with a near identical setup and boat...he's stuck at 80 gps with a 25P prop and wanting more...You're rig should be hauling the mail in a major way so I'm now pretty convinced your issues are motor, not set up.

Scoped: bore scoped...looking at the insides without tearing down, but if you're already pulling heads you're going to get a pretty good look at things.

 

[12pack]

If I remember right wildmans best speed was 81-82 with tm, not sure on prop but I believe he was 1.5" under pad

 

[12pack]

Cylinder sleeves all in correct position, tech is going to test fuel psi while under a load next week.