1998 Tracker Pro Team 18 Jet question

[rocko]

Hello all. We have a 98 Tracker pro team jet 120 XR
We have had trouble getting up to speed recently. It seemed to slip when it gets over 4000 rpms. We just replaced the wear ring and impeller which helped but it still seems to slip. I have been trying to read up as much as I can on the issue without much luck other than check the water pump.
I am not a gear head so I don't know too much but does this inboard jet drive have a water pump or does it just rely on the impeller to suck up the water. The main grate is clean, we had it up on a lift recently and nothing in there.

Looking to bounce this off of you guys, maybe gets some ideas.

Thanks

 

[RiverRat]

How well is the intake grate sealed against the hull? I know on my fiberglass hull there is a good mount of silicone sealing the grate against the hull. I would imagine yours should be similar, even though your hull is aluminum. I know if the silicone is in bad shape or missing, too much air/ turbulent water can be introduced into the pump causing cavitation.

What motor does your Tracker have in it? Is it basically a Force outboard mounted inboard?

 

[Scottintexas]

What does your impeller look like? is it easy to pull the shaft and impeller out (our yamahas take about 15 minutes to pull) maybe get a flashlight and look up from the bottom through grates at the front and take a picture,

 

[rocko]

How well is the intake grate sealed against the hull? I know on my fiberglass hull there is a good mount of silicone sealing the grate against the hull. I would imagine yours should be similar, even though your hull is aluminum. I know if the silicone is in bad shape or missing, too much air/ turbulent water can be introduced into the pump causing cavitation.

What motor does your Tracker have in it? Is it basically a Force outboard mounted inboard?

THanks for the reply.
The seal around it is beat up really bad. We have added new stuff to it several times but never experienced the slipping feel before.

The motor is a mercury 120. I don't know what a force outboard motor is, or looks like.

 

[rocko]

What does your impeller look like? is it easy to pull the shaft and impeller out (our yamahas take about 15 minutes to pull) maybe get a flashlight and look up from the bottom through grates at the front and take a picture,

Brand new, just replaced it last week as well as the wear ring.

 

[robert843]

Before the issue what was your top rpm and is the engine still hitting that rpm? When you changed the impeller was the boat running fine before that or was the reason for the impeller change loss of speed? If your boats engine is still performing the same as before and this didn't occur after the impeller change it is very likely as mentioned a loading issues where the pump isn't getting full pressure. If the seal around the bottom of the pump is bad this could be causing that also check the steering nozzle and make sure it's still lined up at the correct angle someone or something may have hit it and it maybe angled up or down slightly. Last double check your reverse bucket over time cables wear out and they can become out of adjustment if it's not fully clearing the the steering nozzle anymore when in forward it could be causing some drag causing this. How did the teeth on the drive shaft look when you installed the new impeller? Also any unusual noises that were not there before issue? Sorry for so many questions but just more info needed to help diagnose.

 

[rocko]

Thanks Robert, Lots of good questions.

Top rpms around 5600 and it still hits that.
No when we changed the impeller we thought it would fix the issue. Loss of speed was the fist reason then it started to "Slip"
I believe the engine runs well.
I don't know what the correct angle of the nozzle should be. How would i figure that out?
I didn't notice anything about the teeth, could they be worn out. It only "Slips" when it gets over 4000 rpms. You can feel the impeller bite and get a burst of power then it slips again.

 

[rocko]

Just to follow up with this. The ride plate was bent up and causing cavitation. I was able to remove the plate and bend/ bang it flat. Reinstalled and she running like new.

Thx