GTX RFI low speed and 6600 rpm

[Mr Africa]

Hi guys just want some quick info that i can't seem to find on the site.

Right finally i have my ski back after the accident, all soughted.
It has been serviced, new wearing, impellor rebuilt. Now on my first test i found that i was only getting to about 45 mph and the rpm was only 6600 rpm and the wife said it sounded like a butcher saw from a distance away and it would take a while for it to plain off.

When i got home i found that firstly the steering nozzle was facing slightly up, the plastic bush under the steering nozzle was incorrectly put in, when i changed it around the nozzle came down abit. I then found that when the steering bar was straight the nozzle faced to the left. If i stuck a straight ruler in and measured the two sides i found that there was a difference by 3mm. i have straightened that as well. Could all this make the difference in speed and not plaining quickly.

What rpm should i be getting at WOT. On trailer it hits the limiter in the water about 6680rpm. Is this normal.

Can you confirm when i do a sharp turn and then open the throttle full it takes like 2 seconds as if cavitating, is this normal.

When riding is the exhaust fully under the water or only half.

Sorry for all the questions but hey need to know so as not to make an ass of myself.

Thanks
Andrew

 

[Dr Honda]

Hi,

You are pretty close to where it should be. The rev limiter kicks in at 7200 rpm… so you should be right around 6800 to 6900 rpm in the water.

I would check:

1) The RAVE valves to make sure they are clean, and working.
2) Check the water regulator on the exhaust to make sure it’s working.
3) Check for exhaust leaks. (that may be the “Meat saw” sound)
4) Check engine compression. (150 psi is ideal)

As far as the cavitation thing… if you massage the carbon seal… you may be able to get rid of all signs of cavitation… but if you start with the ski in a turn… chances are, you will have a little cavitation.

Finally… speed. You have a big 3 passenger ski with only 110 hp. So… 45 to 50 mph is all you will see.

Good luck

 

[Mr Africa]

Hi Tony

The raves should be clean but i will check them again.
The raves settings full out to all the way in, what is the difference as well as the water regulator being in or out.

On my exhaust pipe coming from the black water box to the exit, It is stainless steel and not rubber as the original. Will that make a difference as 2 stroke motors need back pressure and this is a larger diameter pipe compared to the original.

What do you mean massage the carbon seal. Where is it and how the hell do i massage it. Last time i massaged something i wound up marrying the thing.

I will inspect the exhaust for leaks tomorrow morning as i know that the repairers had to work on the back of my ski ( they had to replace my ladder with the new style which is narrower than the older version) so they could have loosened it while they were busy with the back of my ski.

Thanks
Andrew H

 

[SabrToothSqrl]

Rfi

I thought the GTX RFI was 130HP like my '98 GTX LTD?

 

[Mr Africa]

Hey Sabr

The GTX DI has the 947 direct injection motor that produces 130hp
Mine has the 787 fuel injection motor that produces 110hp.

When i bought it i also thought it was the stronger motor but you learn as you go. Still fun to ride anyway.

Oneday when i grow up i will buy a bigger one (JOKE)

 

[Dr Honda]

Sorry I didn’t get back to you yesterday.

OK… the stainless pipe shouldn’t make a difference as long as it isn’t leaking exhaust gasses back into the engine compartment.

The carbon seal is the driveshaft seal on your ski. If you look behind the engine… you will see a gray plastic cover. It is held on with 2 wing nuts. Loosen them, and it will lift off. Under that you will see a rubber boot holding the black carbon ring tight to the face of the “Stainless ring.” The interface of the stainless and carbon ring is the seal. Make sure that the carbon ring isn’t cracked or damaged… but it’s hard to tell without removing it.

The carbon ring is the first place I look when cavitation starts.

One thing you can check. On some drive shafts, there is more than one clip position for the stainless ring. If you push your stainless ring toward the transom, you may see a second clip spot. If you have that, remove the clip in the driveshaft, and move it. This will put more pressure on the seal, and may eliminate the cavitation if the carbon ring is in OK condition.

 

[Mr Africa]

Hi Tony

Yetserday I removed the water box and other piping checked all and put it all back nice and tight. No leaks (in the process found that drain pipe to the exhaust was blocked with sand).

Checked the raves and they are clean.

I did remove the grey cover and saw what you are talking about. I put some grease in the grease nipple ( about three squirts with grease gun) and i found that it pushed the shaft back slightly.

Why would it do this?

I will check the carbon seal. I remember checking yesterday and the carbon seal moves backwards and forwards by hand away from the stainless ring. I didn't know any better so i left it like it was.

What type of clip will the stainless ring have?
Does the carbon seal release pressure and that is why it will cavitate?

Thanks for pictures makes life a lot easier for the mechanically handicapped.

I am hoping to take it for a test run tomorrow and if all is well then spend the day at the dam.

Thanks
Andrew H

P.S in your picture you have a hose clamp next to carbon ring mine doesn't is that important. Thanks

 

[Dr Honda]

The driveshaft floats in a seadoo... so when you put grease in the PTO... it will push the shaft back a little. As soon as the grease gets hot, it will move back.

The problem with the carbon seal is that if it's warn, or the boot gets soft (it acts like a spring) the suction of the jet pump can actually pull the carbon ring away from the stainless ring... and it will leak air. As soon as that happens... you don't go anywhere. SO... if you push it all back, and put the clip in the second position, then it puts more pressure on the seal, and in turn, it's harder for it to leak air.

 

[Dr Honda]

Like it says in the picture... "You will see the clip once you move the stainless ring."

It's a wire C-clip. Once the ring is moved, pop the C-clip off, and move it one groove up.

 

[Mr Africa]

Hi I can't get my ring to move and if i look on the parts catalogue it only shows one place for the circlip.

The stainless ring can you move it back by hand or do you have to bang it with a hammer or something.
Thanks
Andrew H

 

[Mr Africa]

GTX RFI low speed and 6600 rpm

I don't want to damage anything by hitting it with a hammer. Would this model have an extra groove even though it doesn't show it on the part in the parts catalogue.

Thanks
Andrew h