Need help with my bass tracker running 50 hp merc

Hello good people,

I am puzzled by my issues so I wanted to get some thoughts from experienced people. Any help would be greatly appreciated.

I have a 2006 Bass tracker 175 with 2005 50hp Mercury 2-stroke (50elpto)
Issue: plane, WOT rpm/top speed issues
Boat is with stock trolling motor, added 2[SUP]nd[/SUP] deep cycle battery so 3 total + 12’ talon on the back.

Issues: Boat having a very hard time to get on plane and not getting correct WOT rpm
1 person (210 lb), new 14 pitch 3 blade prop: Gets on plane slow, 22mph top speed @ ~4300 rpm WOT
1 person (210 lb), friends 10 pitch 4 blade prop: Does not get on plane at all. 5mph @ 4000 rpm WOT. This is really puzzling as I thought this thing would plane super-fast, just slow top speed. But it wouldn’t plane at all. Prop pulled from a 21’ pontoon with diff 50hp motor and pontoon ran great.
3 people (600 lb), new 14 pitch 3 blade prop: Will only get on plane if 2 people sit on bow. 16 mph top speed @ 4000 rpm WOT
3 people (600 lb), new 12 pitch 3 blade prop: Would barely get on plane if 2 people sat on bow. 11 mph top speed @ ~3000 rpm WOT. Going from 14 to 12 pitch made getting on plane much worse.
I thought going with lower pitch prop would help with acceleration but it seemed much worse.

What I have done: Rebuild carbs, fuel pump, oil mixing pump, new fuel line, fuel filter, new plugs, air filter. Tested idle and WOT timing (all up-to spec). Idle ~750-800 in gear. Carb idle screws @ 1.5 turn out. Any less and would have idle issues when cold. Went through all adjustments in the service manual. Throttle cable, carb sync etc. Compression on cold engine: 105-115 on all 3 cylinders.
I don’t know what else to try. I really thought the 10pitch 4 blade prop would help with acceleration but it made it much worse, which just puzzled me completely.
My next step is to take it to a marine mechanic but I wanted to check in to see if I missed anything. It’s a long drive and tight on money now. Any guidance would be greatly appreciated.

That's strange all right. I'd recommend hiring an expert here.

Jeff

How is the engine mounted height wise? I have a TX17 that I had a 70 Merc 20” shaft, best mount was third hole down from the top and was using a Merc vengeance 3 blade 18p. Worked great. Got on plane quick and handled well, got 38mph with same load as you.
I just swapped a 92 Merc 100 on last week and mounted it a hole higher out of curiosity and it didn’t work out well. Boat felt like it was pushing water and didn’t want to hop out of the hole at all. I’m guessing that maybe your engine is mounted to low. If your cavitation plate is below the water you need to raise it. Also, you wouldn’t happen to have one of those plates bolted on that’s supposed to help the boat plane better do you? I have found that those made my boat handle substantially worse and made planing out harder. And are you sure the props aren’t slipping on the hub adapter?

These models if lugged have history of sleeves slipping...suggest you rent/borrow a bore scope and inspect cylinders to see if sleeve has turned blocking of 1/2 the ports.

Hey guys,

Motor is mounted on the lowest setting but cavitation plate is even with the bottom of the hull which is a standard setting I believe. Both props were new with new hubs. The Michigan Vortex 4 blade 10 pitch was pulled from my friends 21’ pontoon that ran it few minuted earlier. The only thing is that it's a 50hp Honda and mine is 50 hp merc. I used his hub XHS Hub kit 113 and per manufacturer, XHS Hub kit 114 is to be used. Only difference is the Forward Thrust Washer. I am not sure if the difference is that huge but maybe it caused cavitation and that is why I couldn't get on plane?

@ fazbullet - I have a bore scope somewhere. I'll check out the sleeves to see if they turned.

Thanks!

Forward Thrust Washer (thrust hub?) this has to be correct to keep the prop from pushing into the gearcase which can grind away the bearing carrier and cause loss of power.

I was more thinking that it was to big causing exhaust to leak and cause prop cavitation. There were no signs or any grinding on the prop. I move the two trolling batteries to the bow today, wasn't as bad of a job as I though it would be.

I inspected the cylinders and the sleeves are good. I adjusted the carbs to run a bit richer as I noticed the spark plugs were a bit dry. Thinking about raising the motor one hole but that will take some effort

Hey guys,

So I took the engine apart today and looks like the reed valves aren't sealing good. Top and mid cylinder: 1/6 flaps seem to not seal good but the bottom cylinder has 5/6 sitting slightly pulled away from the reed block. Huge difference in comparison to the other ones. When I rebuild the carbs last year, I noticed a some amount of fuel in the bottom of the air box but assumed it was normal. I got a fishing trip in 2 weeks so I'll report back if it solved my issues

Quicksilver, since you mentioned this I checked mines and sure enough it was on wrong way (sorry to interfere in this thread)... tapered part was facing away from propellor, now I’ve only run it about 3 times that way, saw some black stuff (I had greased shaft previously) and a small amount of had been rubbed between thrust washer and case,don’t see anything major from my POV, just was curious if there is something that I should do besides face it right way?

gotta say why it’s good to read forums cause you just never know what you may find

thanks

My guess is that heavy talon. and mount. Take it off and see what happens to hole shot. Did u just add talon ?

I'm asking because there's a fisherman ,selling 2 -12' talon , Jack plate mounts and everything for $1500, has $4500 invested. Installed it 8 month's ago on 2017 ranger with 250 pro xs. And totally lost hole shot. He removed 1 and got back hole shot have *****$.
I installed a atlas JP 2 weeks ago on a all aluminum 19' Xpress with a 150 VMAX yammy 4 stroke 2019 boat and motor. Customer brought boat back and said it's struggling getting on plane. He had installed 2 10' talons. Said he needed JP for skinny water, so mounted motor at top holes and JP low. He didn't say he was going to install talon's.

Solved

Ended up being a small plastic shaving stuck in the main jet of the middle carb. Enough flow to idle okay but not enough for full throttle. Running great now. Thank you all for suggestions!

Well post # 1 tells folks that carburetors were " rebuilt "-----Some times it takes 2 or 3 tries to get it right.

To be honest, it was due to my inexperience as I didn't see the main jet in the bottom of the bowl. I am glad I kept poking at it. It just didn't feel right for the engine not to reach max rpms with a 10 pitch prop. I am still looking at raising the motor but thinking about getting a jack plate as the rivers I fish have really shallow spots. We'll see