The "GREEN HULK" fix for the GP1800 Intake Grate insert/hull cracking issue

[K447]

Here is some pics of the cracking.

The reinforcement threads were about strengthening the hull in that area before stress cracking occurred.

Now that you hull has actually cracked this is a repair, not just a reinforcement.

The original hull material is now weakened.

To be successful the repair must now make the area stronger than factory.

[Corbetta611]

The reinforcement threads were about strengthening the hull in that area before stress cracking occurred.

Now that you hull has actually cracked this is a repair, not just a reinforcement.

The original hull material is now weakened To be successful the repair must make the area stronger than factory.

Isn't that what Filling in the voids with Fiber and Resin then installing the longer brackets would do?

[Corbetta611]

Filling in that entire void making it a thicker layer and sealing off any of the cracking that has occurred from the bottom, Then putting in the longer brackets that secure to the double layer of the hull pulling the Intake grate into the plate which is now putting the stress on the dual layer thickness of the hull that the bracket is pulling into?

[K447]

Filling in that entire void making it a thicker layer and sealing off any of the cracking that has occurred from the bottom, Then putting in the longer brackets that secure to the double layer of the hull pulling the Intake grate into the plate which is now putting the stress on the dual layer thickness of the hull that the bracket is pulling into?

Correct

Just pointing out that the repair must be really well done to compensate for the weakened hull layers.

[Corbetta611]

Correct

Just pointing out that the repair must be really well done to compensate for the weakened hull layers.

Thank you very much for pointing this out. I would have just tried to rush it along. Now I will clean up the area well, Put fillers in it and try to do a solid job at it. Any recommendations on a strong cloth to use for this application? Kevlar or Woven Fiberglass?

[K447]

... I will clean up the area well, Put fillers in it and try to do a solid job at it.

Any recommendations on a strong cloth to use for this application? Kevlar or Woven Fiberglass?

Previously posted on here is info from Yamaha on how to properly repair NanoXcel (and NanoXcel 2) hull material.

http://greenhulk.net/forums/showthre...=1#post2980960

There are specific requirements for the fiberglass cloth material and for the epoxy resin needed for NanoXcel repair.

Note the use of acetone to dissolve and lift the wax compound from within the NanoXcel material prior to using any resin.

Standard fiberglass repair materials and methods are not suitable.

Since your hull material is now cracked and deformed downwards, you will need to ensure the final lower surface repair levels are back to factory, flat and straight. The repaired bottom hull surface determines the mounted angle(s) of the intake grate, which affects the ride and handling of the entire watercraft.

And you want the repair result to be waterproof. Not just for water leaking into the hull interior but also to prevent water from seeping into the hull material layers.

Additonal info can be found at NanoXcel.shorturl.com

[Corbetta611]

Previously posted on here is info from Yamaha on how to properly repair NanoXcel (and NanoXcel 2) hull material.http://greenhulk.net/forums/showthre...=1#post2980960There are specific requirements for the fiberglass cloth material and for the epoxy resin needed for NanoXcel repair. Note the use of acetone to dissolve and lift the wax compound from within the NanoXcel material prior to using any resin.Standard fiberglass repair materials and methods are not suitable.Since your hull material is now cracked and deformed downwards, you will need to ensure the final lower surface repair levels are back to factory, flat and straight. The repaired bottom hull surface determines the mounted angle(s) of the intake grate, which affects the ride and handling of the entire watercraft.And you want the repair result to be waterproof. Not just for water leaking into the hull interior but also to prevent water from seeping into the hull material layers.

You are absolutely amazing, I made a trip to West Marine today and got everything needed to complete this. It wasn't a cheap trip but it shouldn't have been. I am going to take my time doing this and hope for the best. My thing is going to be covering the stress cracks that fold over the flat surface. I'm thinking chopped strand and a lot of time and effort.

[Peteysparks]

Can anyone confirm these will work on a 2000 XL1200 LTD? I’m in the process of removing the inserts for the intake grate plate bolts. This bracket appears to be a good fix. My WR is in another location at the moment so I can’t get a bolt distance measurement.

[ktherrien]

Want to thank all who are contributing to solving this nasty problem. My 2018 GP1800 was taking in a few gallons of water every minute especially at 68+ MPH in July 2020. By August it was about 10 gallons per minute. I had installed a nice bilge pump to keep using the machine. In September took the boat out of water and the rear intake grate support area was cracked between the bolt holes on one side and torn through on the other. Also the stock intake grate had dozens of stress cracks all the way to the edges most likely doe to flexing. I am running a Stage 1 8300 tune.
Not to brag, I have a Bachelors and Masters degree in Mechanical Engineering from MIT. Worked in Boeing's advanced composite group building plane parts so I has some creds. This cut out in the inner hull and the insert location is one of the most egregious pieces of structural engineering I have see. There is no excuse for this flaw and Yamaha needs to address the issue head on.
So to the fix the problem I followed the suggestions in this thread. Since I had structural damage I rebuilt the fiberglass on the torn side with 8 layers of fiberglass blankets making sure 4 overlapped over the inner hull. Used 4 on the cracked side. Sanded down on the underside and put in 2 layers each side. Replace the intake grate with a Riva plate with larger inserts. A tight fit which is good and sealed the bolts on the underside.

[K447]

... My 2018 GP1800 was taking in a few gallons of water every minute especially at 68+ MPH in July 2020. By August it was about 10 gallons per minute.

I ... installed a ... bilge pump to keep using the machine. ...

... the rear intake grate support area was cracked between the bolt holes on one side and torn through on the other. Also the stock intake grate had dozens of stress cracks all the way to the edges most likely doe to flexing. ...

Not to brag, I have a Bachelors and Masters degree in Mechanical Engineering from MIT. ... I has some creds. ...

You kept using the machine despite rapid water entry, and then added a bilge pump to ‘keep up’ with the incoming water leak rate?

And the leak rate progressively got worse and you kept riding it?

Were you aware of the known problem with the 2017 and 2018 GP1800 hulls cracking in this area?
And the widely posted proactive reinforcement fix?

The rider(s) were at risk for serious personal injury or worse.

You had a water leak and did not investigate the cause?
Did the bilge pump install pre-date the intake grate leak and hide/mask the problem?

You are running above 80 mph which is known to aggravate the stress on the non-reinforced OEM intake grate area. In fact, above 80 the factory aluminum intake grate is recommended to be changed to the stronger stainless steel Riva grate.

If the intake grate had torn out at speed the machine could easily have thrown the rider with violence. Metal intake grate fragments could enter the jet pump and jam the impeller, causing instant rapid deceleration and possible snap hull rotation. Merely losing the intake grate at speed would suddenly change the hull handling, even if it did not jam the jet pump.

If the hull was suddenly torn open at speed it would flood very rapidly, putting the rider(s) into the water in seconds (if they were not already thrown off).

In August you posted about finding and correcting two other leaks.
Did that stop ALL the leaking at that time?

... 2018 GP1800 with a Stage 1 8300 tune with about 100 hrs.

Found 2 leaks. The nylon threaded bushing that allows the speedometer wire to enter the hull was loose. The inside nut was loose by about 3 turns and water was pouring in. Had to take most of the exhaust parts out to get to the nut and tighten.

Next the drive shaft sleeve was spraying water out the front clamp and hitting the plastic wall in front of it. Of course only could see this at load with ski in water. Tighten clamp and will add second clamp soon. ...

My kids run the ski hard.

It seems you and your kids were lucky. Somehow this does not read like the behavior one might expect of an engineer.