Boat won't get up on the pad

[jcreech1]

I have an 82 skeeter with 81 Evinrude 150 on it. I am running a raker 14.75 X 20 inch prop. The motor seems to run strong all the time, but it does not want to push the boat up on the pad. I can get it up on the pad if I turn the boat slightly to the right, but once the boat straightens out, I am back down in the water. I had a Dol fin on it and removed it to see if it was hanging the water. No luck. Could it be bad motor mounts? If so lower or upper? Help....

 

[Dhadley]

Re: Boat won't get up on the pad

Lets start at the begining. What kind of RPM's can you get at WOT? Did it ever get on the pad?<br /><br />Let us know!

 

[jcreech1]

Re: Boat won't get up on the pad

I can get it up on the pad if I am turning slightly towards the right. It turns between 5300 and 5700 depending on the load. The problem exists regardless of the load.

 

[Dhadley]

Re: Boat won't get up on the pad

I understand how to get a boat on the pad. Trust me on that one. 5700 RPM with a Raker on a pad bottom boat is not enough. We have too much drag. Since you are only using a 20" Raker I assume (I know, I know!) you don't have a jackplate. <br /><br />#1, and this is VERY important, has the prop ever been rebuilt? Most prop shops put a Raker on SST pitch blocks and you loose all the lift. Sound familiar? Look at the prop for stamped numbers along the outer hub area between the blades. If it has been rebuilt we will still work with it for now because I think you are going to be able to turn a larger prop anyway. <br /><br />If the motor has room to be raised, do so. Monitor your water pressure along with RPM's and speed. Use your boat speedometer if thats all you have. Right now we're not looking for accurate speed numbers, just changes. <br /><br />What model (lenghth) boat? Is the motor an XP? Are there wedges between the motor and the boat?<br /><br />Lets take it slow and I'm sure you will get "up to speed". Make darn sure your ignition cut off switch (please dont call it a "kill" switch) works and always have the lanyard hooked to your jacket. Especially during testing.<br /><br />Keep us posted! Good luck!

 

[sho305]

Re: Boat won't get up on the pad

Load makes a big difference. Make sure you have no water in the bottom or unneccessary weight. Check your prop for any damage at all, front edge on at least the outer half of the blade should be somewhat sharp or rounded. Play with your trim/jack plate. Your cavitation plate(where the fins mount) ought to be above the water on plane and have no effect then. Find out your max rpm and get to that point for max speed empty, or with your usual load if you have to-just don't overrev it empty.<br /><br />Looks like Dhadley has you zero'd right in in the above post<br /><br />Sounds like it has to do with how the prop is hitting the water and you get a bit more thrust when turning that way a little. Also check for more weight on one side of the boat, and the bottom of the hull for straightness and make sure it is not on the trailer wrong and denting it. Bottom of transom shoud always be on a bunk or roller when strapped down or over time the trailer can push the botton in.

 

[jcreech1]

Re: Boat won't get up on the pad

The prop has had a new hub put in it 2 times that I know of, but other than that I am not aware of any reworking on it. It does not have any obvious weld lines or marks on it. I can see the number on the casting and I will provide it here shortly. It is not an XP to my knowledge (did they make XPs in 1981?). It says "sport" on the housing. The model number is E150TRLCSR. You are correct in that I don't not have a jack plate on the boat (nice observation ). I have been considering, but did not want to make the investment until everything else was performing optimum. The cavitation plate is out of the water when on a plane and it looks like it is roughly 3-4 inches above the pad (prop shaft appears to be about 4 inches under the bottom of the boat. The hull looks straight and there are no noticable concaves or indentions on it. Also, The stamp on the side of the motor says the target operating range is 4500-5500 RPMs with the max HP occuring at 5000RPMs. It is a skeeter starfire 180 DC.

 

[sho305]

Re: Boat won't get up on the pad

It does sound typical of not enough lift. You can't get enough trim to put the bow high enough to get on the pad good. Your prop has lots to do with this, and try another if you can borrow one. What kind of speed are you at? How high is the bow? Does it get out of shape at speed if you hit a wake? Did you move stuff from the front to the back of the boat and see a difference? <br /><br />My 17' has a vee with no pad, but I can trim enough with a LaserII 20 so if I hit a wake it goes air borne easily. At this point I can only run around 50-54mph with a 1973 Merc 150. Raced even with a jetski and he said his was 55mph, and mine was 50 at 5200rpm. It has run 5400rpm @54mph when it was cooler out. Not sure if it is running right or not. Everything checks out and it sounds good but the old owner swears 60+ out of it. Flusterating to say the least. The speedo & tach are new, and the tach has been calibrated. the Merc manual says run a 23 or 25 prop and 4800-5800rpm! Tried a SS 17@5700rpm and did 48mph. It runs the same as the 20 with a 21 Merc prop only 100rpm less and no lift.

 

[jcreech1]

Re: Boat won't get up on the pad

Sho,<br /><br /> I get about 55 (@5500) according to GPS. Your Mercury will trim as high as you can stand it. OMC outboards have a stop sensor of sorts in them that stops them from being over trimmed. Safety feature I guess. I really feel like I should be getting more speed out of the boat as I have riden in similar setups that will leave me in the dust as far as topend goes. My boat is a little bigger than yours (18) but I don't think 1 foot would have that much impact overall. I have moved everything from the front of the boat and then subsequently out of the boat and the problem is not affected by the weight or lack of it. I have tried to turn multiple 3 and four blade props with the only change being my RPMs go down. They were probably to big for the rig (24 pitch). I think I really need a 22 or 23 to stay in my target RPM range. I am not going to make any prop changes until everything appears to be right. I have yet to get the boat in any water that caused it to get akward on the water.

 

[Dhadley]

Re: Boat won't get up on the pad

OK. You have a 1980 standard 150. The prop has been reworked so we can safely assume the lift of a Raker no longer exists in this prop. It will (and is) acting like a 19" SST. <br /><br />Running a 24 Raker or any 4 blade is usless at this point because the motor is not high enough. A four blade is most likely where you will end up but not without a jackplate of some kind. A real good investment whenever you decide its time. Buy the jackplate first, then the prop. I know that sounds backwards but lets try some things first. <br /><br />Raise the motor (free except for some time) and lets see if we can loosen up the hull. You have tons of room RPM'wise. Watch the water pressure and let me know what happens. <br /><br />What do I expect will happen when you raise the motor? Your top RPM's will go up. Your holeshot will get better. Your top speed may increase some (remember we are dealing with a 19" SST). You may start to ventilate at max trim or in turns (a by product of the prop - not the set up). The boat will start to feel "free" or loose (a good thing). Right hand torque in the wheel will increase.<br /><br />A 18' boat will be more stable and faster (in theroy) than a 17'. A 20' will be (in theroy) more stable and faster than a 18'. It has a lot to do with width.<br /><br />Raise the motor (increase the X dimension and let me know what happens. The best thing is to go run the boat as is to determine a base line. Write down everything. Raise the motor. Go run the boat with the same average load and write it down. Forget memory. Then post the results.<br /><br />What kind of steering do you have?<br /><br />Wanna bet we can get over 65?

 

[jcreech1]

Re: Boat won't get up on the pad

Dhadley,<br /><br /> The number on the prop is 5477. Are you guessing that has been reworked because of the age, or do you know some secret that I am not aware of. I know the previous owner and if was reworked, he was not aware of it. I have the motor 1 notch shy of being as high as I can go without a jack plate. What set back should I shoot for? Any suggestions on brand? I have a rotary teleflex steering system. I appears to have minimal torque (easy to steer) once I am on a plane. What is the Max RPM range that I should be running in? The stamp on the side of the motor says 45-5500 is the target range with 5K being the point where max horsepower is achieved. It is an old motor and it does not appear that it has been rebuilt, so I am a little scared to run it past the target range. Not saying that I would'nt, just not very comfortable with the idea of blowing it. I don't know whether I will need to replace the steering cables if I put a jack plate on. I have some length available. The appear to be fine, so I hate to replace them if I don't need to. Thanks for all of the information. I will raise the motor to the highest hole and let you know what happens. 65 would be outstanding. If you think it will do that I will try any suggestions that you have to get it there. <br /><br />Thanks

 

[Dhadley]

Re: Boat won't get up on the pad

Are you saying you have a dual cable Teleflex? Thats good. And to have some slack is even better. I know we are going to go with at least a 6" setback on the jackplate. I really like the plates from Bob's Machine (order line 800-966-3493) whether it's manual or hydraulic. Obviously the hydraulic is top of the line but a manual will work. Bob's will guide you as to the setback. The 6" is convertible to about 1/2 that. They may suggest a 10" for your model boat. Let me know what they suggest. Tell them I (Dale Hadley) told you to call. Don't get into prop selection with them just yet. Most likely we are going to end up with a 4 blade but lets reserve that judgement for later.<br /><br />Once you are up and going 5800-6000 RPM is not anything unusual for that motor. Remember, it's a needle bearing 2 cycle motor. The RPM's are only limited by either a rev limiter or how much air we can get in and out.<br /><br />Since we can only go up one hole the gains are going to be relatively small. But do it and let me know. Call Bob's and talk to either Bob or Rob. There are lots of good jackplate people out there but I trust Bob's stuff. And at a bunch faster than what we are talking about. <br /><br />When in doubt....trim it out!

 

[kevlar3000]

Re: Boat won't get up on the pad

With the RPM increase I would make sure you are running good oil and gas. I run 40 to 1 syntheteic blend ( penzoil) with non oxy gas. I have a 1979 V6 150 Merc on my 74 CV 16. I use a big ear Chopper (tons of bow lift) turn it at 5500 rpm and am seeing 62-63 on the speedo, (likely high 50s with GPS). I just found a 22 small ear Chopper that I hope to gain a couple MPH, and a few hundred rpm. I currently have no jackplate yet... But I am quite pleased with the performance of this "stock" set up with an old fishin merc on the back. I would think you should be able to get similiar results. Have you done a compression check?

 

[jcreech1]

Re: Boat won't get up on the pad

Kevlar,<br /><br /> I have not done a compression check recently, but it runs strong through out the full RPM range. If it were idling rough, or cutting out at WOT, I would have jumped on it and checked it out. I believe DHADLEY may be on the right track with the setup. I think the motor runs to strong for the problem to be an engine issue, but I could be wrong. I will see what I get on the compression.

 

[jcreech1]

Re: Boat won't get up on the pad

Dhadley<br /><br />I now have a 6 inch TH marine jack plate installed and there does not appear to be any binding with the existing cables. I have not run it yet, but have some questions that you may be able to help me with. Do I need special bolts to mount the motor on the jack plate, or can I purchase them from a hardware store? The paper work that came with the jack plate just says "1/2 inch stainless steel bolts" no mention of what grade to use, or even if a specific grade (ex. grade 5 or higher) is recommended. The other question is how high/low should I mount it. It is currently sitting with the prop shaft about 2.5-3 inches below the pad. Any suggestions???