Riva Gen 2 Intake Grate

[Eric Kern]

Hey all,

couple of questions regarding the Gen 2 Intake Grate from Riva and the seal kit.

1) what’s the general consensus on sealing It up? Riva states just around the bolt holes but I feel like you would want It as closed up as possible?

2) With the seal kit, did It not fill each cavity entirely? It seems like the seals from my kit come up just slightly short of being flush with the mating surface of the intake grate, is that normal?

TIA
-E

21 GP1800 SVHO, stage 1+, ribbon delete, intake, crank breather, 13/20 imp.

[Green Hulk]

Normal! Use Permatex Right stuff to seal the grate everywhere it touches the hull. Also apply to the pump seal kit where it mates against the transom plate.

[thomasdjames1]

I have the Gen 2 gate and pump seal kit sitting at my house and plan to install next week.

I am currently running ~79-80 MPH (Speedo) on my 2022 GP 1800 SVHO. I have a Riva stage 1+ kit and flame arrestor removed as my only real performance mods.

Approximately how much speed will the intake grate scrub off the top end?

I still want to install it even if it scrubs speed but just trying to set my expectations. Currently, the ski has horrible cavitation and I want to eliminate or reduce it as much as possible.

I am not sure I am willing to do all the work to pull the transom plate to reseal but maybe I will do that as well.

[Eric Kern]

Normal! Use Permatex Right stuff to seal the grate everywhere it touches the hull. Also apply to the pump seal kit where it mates against the transom plate.

Hey thanks man! Appreciate the info as always!

[Eric Kern]

I have the Gen 2 gate and pump seal kit sitting at my house and plan to install next week.

I am currently running ~79-80 MPH (Speedo) on my 2022 GP 1800 SVHO. I have a Riva stage 1+ kit and flame arrestor removed as my only real performance mods.

Approximately how much speed will the intake grate scrub off the top end?

I still want to install it even if it scrubs speed but just trying to set my expectations. Currently, the ski has horrible cavitation and I want to eliminate or reduce it as much as possible.

I am not sure I am willing to do all the work to pull the transom plate to reseal but maybe I will do that as well.

I’ll let someone speak to that which has actually been riding It. Riva says zero, most comments Ive seen are 1-2 max.

[Mr. GP1800]

You’ll lose 1-2 mph possibly. I think the 2021 stock intake grate and the Riva gen 2 are roughly the same design so maybe you won’t lose as much as the 2020 and earlier GP1800 SVHO. I lost somewhere between 1-2 mph on my 2017.

But the improvements everywhere else far outweighed the speed loss in my opinion. If you want a great running all around ski the gen 2 grate is the piece you need.

If all you care about is chasing top speed numbers there are better choices.

[Green Hulk]

The Riva Gen2 grate on this ski is incredible. The difference in acceleration and hookup is HUGE!

[thomasdjames1]

Anyone had issues sucking up stuff in the pump due to the larger inlet? The stock openings are not small now days so I assume it is a non-issue but figured I would ask before being stuck somewhere!

[Green Hulk]

Anyone had issues sucking up stuff in the pump due to the larger inlet? The stock openings are not small now days so I assume it is a non-issue but figured I would ask before being stuck somewhere!

You don't suck up any more debris than you would suck up with the stock grate. That's an internet myth!

[thomasdjames1]

You don't suck up any more debris than you would suck up with the stock grate. That's an internet myth!

Exactly what I figured! Thank you and hopefully I will have it installed next week!

[Eric Kern]

Ok, so here’s the update sealed It up everywhere with the right stuff, hooks up great. Now getting some bucking around 65/70.

[Eric Kern]

Looks like the seal that sandwiches between the grate and ride plate blew out into the ride plate! Damn!!! Tightened both intake grate and ride plate to spec (12.5 lbft If I remember). Any secrets to this other than tightening above torque spec?

[Eric Kern]

(Why did I ever f*** with It)😫😫😫…sulking over..

In order to line up the bolt holes in the grate with the threaded inserts in the ski, I have to pull the grate off the transom plate by about 1/16”-1/8”… anyone else ever seen this?? Anybody have a solution in mind? I can elongate the holes in the Riva grate but is that just asking for trouble?(ie the second It gets any sort of high pressure It will probably just slip in the elongated holes and the gap will split open)

[jetdawg701]

I’ve installed several of these Riva intake grates and just like most other grates they usually need some tweaking. It seems the four rear bolt holes could’ve been a bit larger to accommodate hull tolerances. Also, I usually grind the back tips of the grate as it seems to be a bit long and causes it to bind against the hull at the front of the grate.
It’s important to test fit the grate and make modifications to it before threading and tightening the bolts or you risk galling up the bolt threads or damaging the factory inserts.

[K447]

I’ve installed several of these Riva intake grates and just like most other grates ...

Is this problem specific (or mostly occurs) with certain models or years of Yamaha hull?

Are you using feeler gauges to determine whether the intake grate has sufficient clearance at the top rear and/or the very front?