Yamaha Waverunner GP800R

[L14MNP]

Well, TJ asked if I had a build thread, so I thought I might as well make one. A few other members have also shown an interest in the ski, so here it is.

I am over on PWCforums.co.uk also, but no thread there. PNG is the place for non-Nova threads, and now it seems, non-car.

OK, a little background first (nautical puns to be expected). I have wanted a ski for ages, years so finally took the plunge on this 2001 GPR, after reading up a little on them, as my knoweldge of them didn't extend past renting one abroad.

I went for an N/A 2 stroke, as they are more reliable, and although you hear they are heavier on fuel than a 4 stroke, I disagree.

The 120 hp 800cc motor in mine is a very good compromise between power and economy.

A 60L tank of unleaded and Yamalube 2 stroke PWC oil will last all day (a long time in jet ski's!)

So this one came up locally, very locally infact. It was only 4 miles up the road. I broke the most vital rule in the book when buying though, I didn't do a water test!

Luckily, it was fine. Had I bought a Seadoo then it could well have been a different story,

The GPR is exactly what I wanted. A race winning hull design that just loves wave jumping and dicking about, and is very agile.

I paid £1500 for it, and it came with receipts for a full engine rebuild from Jet Shed only around 10 hours ago. The rebuild alone totalled over £1900. It still had around 1/4 of
a tank to burn before it was fully run in.

It had also recently been painted white and had no real graphics to speak of. This was a shame, but wasn't gonna stop me. It also runs premix, that is to say the sometimes troublesome oil injection
has been disabled.

I was told if you pay that kinda money for a ski, then it's highly likely you get burned - luckily I escaped!

As I bought it



First time out, I ran into some other locals on a Waveraider, one got a backer from me down the river and out into the sea along to the beach.

Bearing in mind I wasn't meant to give it full throttle until run in, it was bloody quick! The
'dreamometer' reads in KPH, and was showing 110 in next to no time, two up with a only quick WOT burst after accelerating from half throttle.

They are meant to do just over 60 mph when new, and I reckon this one is right on the money still, maybe even a little quicker.

Right, we follow the Waveriader to the beach where he beaches his ski to empty water out of the hull (exhaust had a hole in it) so I beach mine too, and assist.

When sorted, I offer the lad a shot on mine. He hops on, I start pushing it out and he barks it up, sucking a load of stones straight into the jet pump in the process.
I was about to tell him the water was still too shallow! :/

The engine cut out immediately and was jammed when hitting the starter.

Jetski's don't like stones!

[L14MNP]

So here we are, me with my new toy, on holding it on it's side whilst it lies in all the stones on the 'beach' with the tide lashing in, scratching the sh!t out of it whilst I let some random who seems to have half an idea what to do strip part of my jet pump apart to eventually free a 3x1" stone!

Thankfully, after the surgery, aside from the new battle scars, it seemed fine afterwards at least, and I had a riot in the sea!

Were it not for the tidal slipway/rocks everywhere I would have asked for a tow and recovered it on the trailer to inspect later.

Was gutted about the gravel rash right down the side, but hey ho!

So a few more outings come and go, but my smile doesn't!

Until after airshow day (I got stuck in the river Wear at its lowest that day, 1') lol

I decide to trailer it down to my mates in Somerset whilst I am on holiday, we take it to Middlemoor watersports lake. Some 20 acre manmade thing. It wasn't great tbh.

It is there though that the ski developed a cavitation problem, it feels like a slipping clutch, and as you can imagine, severely affects the acceleration, but thankfully not so much the top end speed. So we used it there, after being told by the lake owner that it is the wear ring in the pump,
and it won't wreck anything else.

Two days later we took it to Exmouth beach.

That was a great day! The lack of instant acceleration was mostly made up for by jumping large boats wakes and playing with other skis.

When I got back home I stripped out the jet pump, and found what I was expecting




A dented impeller and worn wear ring - cheers stones!

What I didn't expect was that my impeller was a Solas Concord, and it also had a PPK pump stuff kit fitted, Riva Yamaha trim tabs, pump shoe, ride plate, intake grate etc - very worthy mods for speed, handling, reducing cavitation and cost coming on £1000 on their own. :)

I sent my pump assembly to Jet Shed in Yorkshire to have the impeller repitched, bearings replaced, wear ring replaced, and the whole thing balanced.

Upon its return I refitted it and then a few weeks later (as I lost a trim linkage piece so couldn't attach the nozzle to the jet pump) I took it for a blast at my newly joined marina, Hartlepool.

A mate who has rented skis on holiday before came along. I took it out to warm it up, and played about for around 10 minutes - it was awesome! Instant hook up and far superior acceleration than it had when I first bought it.

£300 well spent imo. Others may disagree lol.

So my mate jumps on, is out about 10 mins, then radios me (luckily I had just bought some submersible UHF's for marina/emergency communication).

He tells me it's stopped dead.

I assumed it could have been the battery. One of the terminals has bounced loose before, but nope.

He was towed in by a friendly RIB, and upon arrival, I hit the start button and could hear the starter spinning freely, not good!

After speaking to a mate from PWC forums (he also once overed my ski ater purchase, compression test etc - stuff I should have done and said I got a helluva deal, and he's a stand up man. So pleased with that.)

I had the mission of removing 'the front cover' to get at and assess the starter.

Many hours later, I had the exhaust and starter off, and then front cover.

This involved removing allsorts. Nothing like I had ever planned getting into when I bought it.

They are pricey for parts, and even worse if you don't roll your sleeves up though, so I am more than game to save some money and expand my knowledge on the thing!

The front cover is also the front engine mounts, and they are shimmed. It was all getting a bit scary tbh. As the shims on the mounts balance the engine with the prop. So they are critical.






Inspecting flywheel/starter/stator (the copper wound thing, basically the alternator)

As you can see, there is no room at all. The flywheel end of the engine faces the front of the ski, and there is no room to get your head in.

The starter looked OK (sounded grumbly though), the stator is toast though. Something has been bouncing about in there, but what?

Turns out to be part of this! I recovered the small pieces, and if further proff was needed, you can see where they originated.


The Bendix/starter reduction gear. Does what it says, and bridges the gap between the starter and flywheel.
I could feel it was knackered once I removed the front cover. So much slop it was unreal.

It's only meant to turn one way.

To unplug the stator I had to actually, factually remove a million and one bolts from the electric box. I reckon it's pretty waterproof!



So I let it at that, and took it to Dodgers the next day, when I found out what had gone wrong.

The Bendix contains two centrifugal clutches, and due to water getting in the front cover (thanks to it being poorly sealed by a previous owner - you didn't need the sealant - the rubber gasket is there for a reason!) the oil on the Bendix had been washed off and it came to bits, then was very nicely fired at the stator by the magneto/flywheel. Hence it dying on the water.

I do wonder if it was the same guy that sent the engine off for rebuild. As I can't see why else the stator would need to be removed normally.

Cheers! lol

Incidentally, starters, stators and bendix units do break, so it's better in a way that I am replacing all of these in one go. My ski will now be in tip top condition. :)

Coming from a car background, I thought nothing of the rust on this mild steel part



but it transpires that it shouldn't be like that, hence people knowing water got inside the case. All makes sense when explained!

So Dodger and I decide to remove the flywheel to be able to access/remove the Bendix. What a **** it was. Held on so tight it was unreal.

I now reckon this was cos the Bendix had stayed engaged with the flywheel and heated it right up. Reckon?

Teeny tiny 2 banger



lol
Still couldn't remove the flywheel at this stage. So we removed a few more parts...


Finally it was in the right position to come off.

It was at this point that I decided to just pull the engine out and go ahead with a full respray. I was initially just going to have the top deck (above waterline) repainted.

We inspected the engine, bores were superb. Brand new as claimed. Powevalves were great, and it's only down 3 psi on one cylinder. Has dropped a PV in the past (commong fault) had
waveater clips installed on rebuild so it can't happen again,

Very pleased with the engine itself.

I made a list, and ordered some parts. Starter rebuild kit, new bendix, new stator, new inner exhaust hose - split mine removing exhaust, and a few cosmetic odds and ends, stern drain plugs, new fuel and oil caps, few seals etc, stuff I wanted to have painted and stuff that had white overspray on.

I stripped it down

[L14MNP]

FFS. Wordpad has ballsed this up royally!

Also, twice now, somehow I have managed to wipe my last few paragaraphs with the touch of a single key?

I will sort this tomorrow. :/

[L14MNP]

Stripped it further than this, but don't have pics.




The lovely glue holding on the mats









You get the idea.

[brainsnova]

It's a good read I would always be wary about pulling away unless it's in the water but overall it's a top motor and seems like a great purchase after you get the bits sorted

[L14MNP]

It's a good read I would always be wary about pulling away unless it's in the water but overall it's a top motor and seems like a great purchase after you get the bits sorted

Cheers Brian. It's a great ski, and as you say, sort the stator and bendix out, then everything else is like new. It needs 3' of water to run properly. TBF to matey who sucked up the stones, I was pushing it from the side, and was up to my chest, so he assumed it was OK to go. Must have forgotten/not realised it is 10' long, and the jet nozzle was still in the sand!

Notepad really annoyed me there, it ruined all of my links and sentences. I couldn't leave it , so have attempted to sort it now.

[L14MNP]

So, only 4 weeks later than promised, it returned from the bodyshop! Thankfully, I seem to have got the job I was promised, so that's a relief.

As said previously, I was initially going to keep the hull white, and even the top deck. Like this:



I wasn't fully decided though, and also liked the look of this (ironically the colour scheme and graphics it would have had originally)



I was drawn to these styles because reproduction graphics are available. I'm not much of a fan of some of the aftermarket stuff - of the prices! So, given that I wanted vinyl, I was fairly limited on choice.

I stumbled across the final style though, and knew that was the one I wanted:



I had the vinyl reproduced to read 'GP800R' instead of GP1300R, and set about the mission of discovering the paint code...

It transpires that Yamaha don't release the codes, so after taking a USB stick full of 'Deep Purplish Blue' ski's and Team Yamaha blue R1/R6's to my local paint supplier, we came up with 'Lamborghini Candy Apple Blue Pearl' as a suitable very close match:



I decided on 2K base for the hull, and antiscratch laquer over the whole thing.

Here it is after I collected on Saturday morning:




and after beginning the refit



Can't wait to get the vinyl on.

Cheers for looking. Will keep you up to date on this - if you wanna be?

[Andy]

Good project,summat different.I know nothing about jetski's but it looks a good laugh

[Graeme]

Looks good mate I had a 93 Seadoo xp and loved it to bits but was worse than a Nova for needing spending on it

[L14MNP]

Cheers Andy. It's good to mess about with something that's not a car for once. Although they're also barely related to a bike, which came aa a bit of a surprise. I expected more similarities. The engines are mental really. No clutch/box (newer and larger stuff have neutral and reverse) it just trawls as soon as you start it, so recovery can be interesting

Thanks Graeme. I looked at Seadoo XP and SPi's before opting for the GPR. They remind me of most of the skis I have rented whilst on holiday. Love the in ya face colour scheme on lots of them too!

What was up with yours then? Generally speaking, if flushed and washed after use (if used in salt watr) and properly winterized, you shouldn't really get many problems, but it all depends who has had their hands on it before you I guess!

Did you use yours much? I have added around 24 hours to mine since buying, so although to some it may seen unreliable, it's actually not doing bad at all - i'm sure you can understand that mate.

Obviously I am.insured, but I do find hilarious and a bit crazy that anyone can just turn up to an open slipway, stick it on the water and away the go, causing all kinds of issues.

eBay skiers they are known as, no PFD, radio etc etc and give us a bad name. I like to think I am slightly above that level