5 hp will it plane???

I have a Achillies 8.5 air floor with a 5hp 2stroke merc. Two adults total 400 lbs, it will plane at 1/2 throttle (with the "majic" tabs). Without the tabs - forget it!

By the way - 99 bucks + more for shipping than the co. web site. It's within a few bucks with the actual co.
 
Last weekend I took my 8.5 Zodiac w/ woodfloor & 5hp 2 stroke Merc out on the bay and the thing was plowingggg with less than 380lbs..
I ordered the tabs today.. Let see how this goes...
 
I ordered a set of the lifters today for a 9'2" hard bottom Achilles with a 6HP Suzuki 4 stroke. I'll be bringing the lifters to the Bahamas next week, assuming they arrive by Wednesday. My plan is to run the boat as is, then install and compare the difference. Since the last time I ran it, I added the hydrofoils to the motor, but haven't run the boat since. I don't expect the foil will make much difference but I have higher hopes for the lifters. We'll see.
 
I still cannot seem to get up on plane with two people even with those tabs. Where I boat I need to get up on pane, I travel upwards of 10 miles round trip on the raft sometimes and it sucks when It is just plowing though the water. I do not want to get a different motor because this motor is light and easy to store. I did notice that the prop slips a little and I am wondering if this will affect my performance. The prop does have a few dings in it, will this make the prop slip? I noticed that Mercury offers a High trust prop, will this give me the power I need to get on plane or will it just give me more torque at the low end? If I did buy a new motor would the 6 hp 4 stroke be a big power difference over the 5 hp 2 stroke?

oh I did loose 10 lbs over winter, that might be the trick:lol:
 
I have an 8'6" inflatable with a high pressure air bottom. Originally I had a 4hp tohatsu 4 stroke. It wouldn't even think about planing. I added the tabs. they did nothing. I then put supports on the tabs to force them down. This helped and it would plane with 1 person at wot. I then added the 6hp carb to my engine to up the power. This was like night and day for one person, it planes and goes pretty well. However, with two people it still doesn't. I've now accepted that short of putting a 9 horse on it, this little boat wasn't meant to plane with two people.
 
I have an older 5hp Nissan 2 Stroke and 8 1/2' WM Soft Bottom. I have no trouble getting up on plan 300lbs and under, no tabs but considering adding them.
 
We have a 12.5 Zodiac with soft bottom. With a 5HP Merc and 3 light people it sort of planes. Put any gear in it and it a slow boat.
 
9'6" RIB, 6hp 4-stroke Evinrude, stingray add-on, average gear and I go about 240lb. With me and gear, it will plane if I sit in the middle until she's up, then it will haul arse, for a 6hp. It will plane pretty good with two 150-160lb adults but takes a little work to get up. A 9.9 would be the answer for my boat with two adults, including my big arse.
 
Don't let anyone tell you that 4 strokes and 2 strokes are the same horsepower for horsepower. The 2 strokes are much more powerful than the 4 strokes. I've personally seen 5hp two strokes haul the mail, and 6hp 4 strokes on the same boat can't get out of their own way.

This is coming from someone with a 6hp 4 stroke!
 
It sounds like my motor may not be performing like it should. I will have to give it a tune up this spring. Does anyone know if there are any cheap things that I can do to increase the power of the motor, like a bigger jet in the carb? also does anyone else have any issues with their prop slipping?
 
I would check that prop slip and maybe fix or buy a new prop. change the plugs and make sure they're gaped right, I under gaped a smidge for a little hotter spark but my engine is different so YMMV. Also play with the drive angle and tabs. Playing with mine, i'm able to hop on plane quicker but lost a little top end. make sure the whole fuel system is clean and that you're running the right oil mixture. I have a whale tale on my drive, it came that way so I don't have any reference of before and after, but it seems to help. You can check if there's a kit to up the fuel delivery, but before you do that, make sure the cable is adjusted right and that full throttle is full throttle.
 
390x said:
I have an 8'6" inflatable with a high pressure air bottom. Originally I had a 4hp tohatsu 4 stroke. It wouldn't even think about planing. I added the tabs. they did nothing. I then put supports on the tabs to force them down. This helped and it would plane with 1 person at wot. I then added the 6hp carb to my engine to up the power. This was like night and day for one person, it planes and goes pretty well.......
Click to expand...

That's a good info. Can you share a bit more details on the 6hp carb mod? Is it as simple as taking a carb from the 6hp motor and install it on the 4hp motor?
 
Alex F said:
That's a good info. Can you share a bit more details on the 6hp carb mod? Is it as simple as taking a carb from the 6hp motor and install it on the 4hp motor?
Click to expand...

A lot of times thats the only difference between 2 motors - a lot of guys on HP limited lakes will put carbs from a 15 on their 9.9 to get back to port quicker - if you look at motor specs a lot of the time the only difference between a 4 and 6 hp for example is the RPM at which they make peak power - the bigger carb is responsible for most of that increased rpm and therefore, power - dont think of it as hopping up the 4 but rather de-tuning the 6 - as some of these motors get more complex there may be a few more differences but the "carb trick" has always worked (unless you already have the highest rated engine from a particular block or series)
 
Yes, the only difference, engine-wise between the Tohatsu 4,5,6 hp motors is the carb. Put the 6hp carb on the 4, and voila, you have a 6. Same with the 4-6hp mercs. They're built by Tohatsu.

IDIDNTDOIT is exactly right.
 
390x said:
Yes, the only difference, engine-wise between the Tohatsu 4,5,6 hp motors is the carb. Put the 6hp carb on the 4, and voila, you have a 6. Same with the 4-6hp mercs. They're built by Tohatsu.

IDIDNTDOIT is exactly right.
Click to expand...

Great! I guess the $64K question is where the best place to get 6HP carb for a good price?
 
Can't put a new jet in because it's a fixed jet. I'm kinda chapped. I just looked it up for you, and it's 15 bucks cheaper than I paid last August!!!!!!!!!
http://www.nissantohatsupartsstore.com/3r4032001m.html

I had thoughts of taking the head off and opening up the intakes and exhausts a bit more to see if I can squeeze some more power out, but then that would require a jetting change, which can't be made on thise carb!
 
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What about the stab fins that attach to the outboard? Would they do the same thing?
 
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