ISO 125-150 merc

[Fishaholic]

I'm thinking of repowering my boat with a 125-150 merc can anybody point me in the right direction? I currently have a 2003 115hp 2 stroke tracker merc and am just a little under powered with a full load. Sometimes it won't plane off or take forever to get there. Talking to other people with the same exact rig they say they have the same issue and upsizing resolved the issue.

[tkwalker]

Originally Posted by Fishaholic

I'm thinking of repowering my boat with a 125-150 merc can anybody point me in the right direction? I currently have a 2003 115hp 2 stroke tracker merc and am just a little under powered with a full load. Sometimes it won't plane off or take forever to get there. Talking to other people with the same exact rig they say they have the same issue and upsizing resolved the issue.

It sounds like to me this is a prop problem ... What are you pushing a barge ?..
I've got a 1500 pound aluminum Boat, decked out, then add passengers with a 50 HP 4 stroke that planes out with no problem ...

So you think by going to a 125 (10 more HP or even a 150, 35 more HP) will elevate your problem .... Well maybe ...

You have a prop issue ... A 115 should take care of any planning situation ... Or it kind of sounds like maybe you just want to up grade to a larger motor and using the planning issue as an excuse ? LOL

Your Prop is probably to tall, what I mean by that it is set up for top end speed. Example: lets say your prop is a 23 pitch, you may want to reduce it to a 21 pitch for a better hole shot now your top speed will reduce somewhat .. <'TK><

[Fishaholic]

Close to it. Its a 188 sport tracker nitro fish/ski weighs 2900 lbs. It has the right prop on it according to tracker. I may have another issue with either the throttle cable or carbs because top end rpm I've worked my way up from 3700 when I bought it to 4500 now using a lot of carb cleaner, replacing plugs, in line filter, and running good gas through it. I'm still a little short because it should run 5500 ish and will rev that high in neutral. Tops out at 38 with four adults and sluggish on plane. Tops out at 43 with just me in it, but add a 5th and it may or may not plane off at all. It seats 7 and with 7 in it, it is a party barge.

[tkwalker]

Sounds like fuel issues. I was assuming the motor was running at it's peak performance ... <'TK><

[Fishaholic]

What you said got me thinking about the prop so I did some research and then went to the prop shop in East Nashville to confirm what I found. Sure enough I should have a 19 pitch and instead I have a 22. As soon as I told him what I had he told me how my boat ran and he was on point with it. He also said with the 3 inch difference I should gain my rpm back to what it should be 5500ish WOT, and plane off a whole lot better. Saturday will be trial day so I'll post an update then hopefully with some pics. Thanks Again TK!!

[Fishaholic]

put the new smaller prop on and first run ran like a champ made 5000 rpm topped out 38 mph with 2 people in it and jumped up out of the hole like it should. Cruised at 4K at 30 mph and throttle would gun back to 5k back and forth no issues. Came down from plane and idled around some garbage in the lake then tried to plane off again but then it started bogging down on subsequent plane offs like before and would only top out at 4k at 30 mph. Brought it in took it apart sprayed a bunch of carb cleaner again got it back to 4900 again but then started bogging down again but at least it always planed off without an issue. When it was only topping out at 4k I tried choking it to see if that would open it up more but it didn't. I only run high octane non-ethanol fuel with seafoam to boot. Any other thoughts would be appreciated. Happy with new prop I think it was definitely the right move cuz even running bad it still planes off where before it would be a barge. Did mange a couple bass on a popping frog with hula skirt but a slow hot morning

[tkwalker]

Originally Posted by Fishaholic

put the new smaller prop on and first run ran like a champ made 5000 rpm topped out 38 mph with 2 people in it and jumped up out of the hole like it should. Cruised at 4K at 30 mph and throttle would gun back to 5k back and forth no issues. Came down from plane and idled around some garbage in the lake then tried to plane off again but then it started bogging down on subsequent plane offs like before and would only top out at 4k at 30 mph. Brought it in took it apart sprayed a bunch of carb cleaner again got it back to 4900 again but then started bogging down again but at least it always planed off without an issue. When it was only topping out at 4k I tried choking it to see if that would open it up more but it didn't. I only run high octane non-ethanol fuel with seafoam to boot. Any other thoughts would be appreciated. Happy with new prop I think it was definitely the right move cuz even running bad it still planes off where before it would be a barge. Did mange a couple bass on a popping frog with hula skirt but a slow hot morning

Like previously stated ... Fuel issues ... Blowing Carb cleaner through a carb apparently isn't working ... Have you thought about getting the carbs rebuilt ?? PS your wasting your money running high test in these motors ... <'TK><

[TroutFiend]

Had an issue with my 9.8 TOHATSU here recently. Had a rough idle and hard to get started. I cleaned the carb and replaced impeller since I was tearing into it. Turned out all the problem was a clogged inline fuel filter!

[Fishaholic]

TK I have looked into Card rebuild but I figured for the money it would cost to do that I might be able to trade up for just a little more. Also with everyone so booked out I don't my boat sitting somewhere for weeks unused. Troutfiend I will look into that too that is a good idea.