521c with new 250 V8 Merc and Hotfoot problems

[JThomas]

Hey guys I got my new boat with the new Merc on it and I was not getting full throttle with the top load hot Foot. 5600rpm and 64mph is all it would do. I took it back to my dealer and they said that they had discovered that the top load was not letting the motor get full throttle consistently. They wound up putting the universal bottom load one on and I hate it. It gets full throttle now and gets to 6200 rpm now with no issues. I called TH Marine today and the guy I talked to had no idea what I was talking about. I want the top load back so I can save my ankle lol. Has anyone else had this problem?

[howieranger]

There is no reason a top load wouldn’t work.

[CaymasRodney]

There is no reason a top load wouldn’t work.

100% agree

There is an adjustment screw on the back to get the adjustment that you need just like the bottom load!!

[JThomas]

I didn’t think so either but I’m no boat mechanic. They said it would show 100% throttle during the initial setup and testing, but when they shut the power down all the way and then powered it back up, they would test and it would only show 80% on the computer. They would adjust again to 100%, shut it down and again have the same problem. They did it multiple times and also had the other problem on other boats.

[bassburch]

Not sure I buy it... what they explain sounds impossible. Its a mechanical cable pulling the throttle open, and it stops when the hootfoot bottoms out on the adjustment screw. Nothing related to the hotfoot can magically change this from 100% to 80% throttle without adjusting that screw. Something else is/was going on in my opinion.

[JThomas]

Update: Apparently there was an issue with the current top load. From my understanding, TH Marine and Ranger came up with a fix by modifying the side plate to allow more throw. Right now it is only available through Ranger Parts. I had my dealer install mine Tuesday. We went through 7 power cycles and it showed 100% every time. Part number from Ranger is 324552.

[CaymasRodney]

Update: Apparently there was an issue with the current top load. From my understanding, TH Marine and Ranger came up with a fix by modifying the side plate to allow more throw. Right now it is only available through Ranger Parts. I had my dealer install mine Tuesday. We went through 7 power cycles and it showed 100% every time. Part number from Ranger is 324552.

That’s good to know thanks for sharing!!!

[mactlman]

Not sure I buy it... what they explain sounds impossible. Its a mechanical cable pulling the throttle open, and it stops when the hootfoot bottoms out on the adjustment screw. Nothing related to the hotfoot can magically change this from 100% to 80% throttle without adjusting that screw. Something else is/was going on in my opinion.

should be a fly-by-wire throttle on a modern motor??? no cables?

[howieranger]

On the CMS motors you have a standard cable to the motor and that moves a sensor that sends a signal to the PCM to open the throttle which is electronic. Something does sound fishy.

[Javman389]

Had a buddy just buy a new boat with a 4 stroke Merc, hot foot will not return to idle. He has to pull it back with his toe. He talked to T & H and they told him there was/has been a problem with the recent run of hotfoot.

[EuropeanAM]

Hotfoot IDLE STOP is extremely critical on these engines- far more than previous 2-stroke models as the stop on the HOTFOOT at idle is the primary point from which all throttle settings will run.

If that throttle linkage doesn't come back to the same point each time... it will be incorrect when it adapts the next time (at keyup or startup).

[CaymasRodney]

Hotfoot IDLE STOP is extremely critical on these engines- far more than previous 2-stroke models as the stop on the HOTFOOT at idle is the primary point from which all throttle settings will run.

If that throttle linkage doesn't come back to the same point each time... it will be incorrect when it adapts the next time (at keyup or startup).

Kind of like the old Fichts, if it wasn’t set dead on it would throw a code every time.

[241]

OK I just got a new hotfoot that supposedly has this issue fixed. I can't see the difference between old and new. Anyone know?

[JThomas]

OK I just got a new hotfoot that supposedly has this issue fixed. I can't see the difference between old and new. Anyone know?

If yours has a “c” notch cut out of the side plate, you have the new one.

[241]

Can you suggest any initial settings? Do I start with the peddle all the way into the c channel?

[JThomas]

Can you suggest any initial settings? Do I start with the peddle all the way into the c channel?

You will need to have mercury laptop hooked up to the engine to get throttle position readouts. My dealer had to adjust the cable quite a few times before it was reading 0 to 100% with the travel of the hot Foot.

[241]

OK I'll tell my dealer. This is their 1st pro xs v8. And not really familiar with hotfoot.

[241]

is this the new one?

[241]

[JThomas]

You have the new one. This is the notch I was talking about. I have no earthly idea what they did different to it LOL but it made mine work like it is supposed to.