Update on the Yamaha WaveRaider 760

"MontegoMan562 is a Capri RS Owner" (montegoman562)
04/24/2019 at 11:52 • Filed to: FannyPack, Fanny, Pack, Yamaha, Motor Swap, PWC, Boatlopnik, Jet Ski, Watercraft, Yamaha 760, WaveRaider, WaveRaider760

Hi Everyone, the last title for an update about the water toys affectionately referred to as the Fanny Pack I had !!!error: Indecipherable SUB-paragraph formatting!!! in the headline.

That was an understatement.

So, after seeing the completely destroyed 2nd cylinder in the Yamaha I ordered a remanufactured motor from SBT, the biggest name in watercraft jet motors. It came in last week and I started the process on Friday of removing the old motor. Good god is that a tiny engine compartment to work in. Here’s some photos starting from pre-tear down to an empty engine bay:

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Quite an adventure removing this thing and placing the new one in.

That wrench buried under the bottom of the motor- after about 15 minutes of making tiny turns I decided “screw this, there has to be another way” and I was able to in an incredibly awkward position get a socket on that from the other side with extensions. Taking out that exhaust was a monumental challenge and my directions through out this are shared between 701 cc and 760 cc yamaha motors...which are all just a little different and they of course only showed the 701 in it.

Once I got the motor out, I had to remove a rubber engine mount right from the bottom of it to repurpose on the new engine. That’s where I discovered I was going to owe SBT some more money (they way of watercraft of any kind right?). When the cylinder let go it blew straight through the crank case! Check out this hole and crack in the bottom! Good thing I didn’t do the top end rebuild I was thinking about doing instead of a whole new motor! That would’ve been a huge waste of 5-600 bucks!

hole is about the size of a nickel

So, I’m waiting on a new PTO coupler because frankly, I couldn’t get the old one off and it cost $14 shipped on ebay. After a couple hours of my time I said screw this and ordered a new one. Until that arrives there are only a few things I can work on so I’m at a bit of a stand still on Pack.

Haven’t even started on Fanny yet which I plan to replace the piston and rings on the rear most cylinder due to it’s low compression. Trying to do some preventative maintenance so that motor stays together for a while. I’d like to only purchase ONE remanufactured motor this year.

DISCUSSION (14)

lone_liberal > MontegoMan562 is a Capri RS Owner
04/24/2019 at 12:28

I see you have one of them fancy extra ventilated crank cases. Very nice.

boredalways > MontegoMan562 is a Capri RS Owner
04/24/2019 at 12:28

That has to be the most naturally occurring FU damage I’ve ever seen — th e nerve of your cylinder pointing in the direction of your issue!

What a cheeky bastard.

MontegoMan562 is a Capri RS Owner > lone_liberal
04/24/2019 at 12:48

Yeah some people pay more for breather attachments, what a waste of money!

MontegoMan562 is a Capri RS Owner > boredalways
04/24/2019 at 12:50

LOL, the engine misbehaved so bad I’m stuffing it in a box and mailing it away to be someone else’s problem!

seriously though, man the worst part is unless you have a scope or a really good dentist mirror , there is really no way to see that the damage is this extreme until the motor is out.

ShrimpHappens, née WJalopy > MontegoMan562 is a Capri RS Owner
04/24/2019 at 12:54

Is this one 2-stroke or 4?

MontegoMan562 is a Capri RS Owner > ShrimpHappens, née WJalopy
04/24/2019 at 13:13

Both of mine are 2 stroke. This one is a 2 stroke 2 cylinder 760 cc twin carb. The Polaris I have is a 2 stroke 3 cylinder 780 cc TRIPLE carb.

all the carbs lol. 2 engines and 5 carbs....I must be insane.

ShrimpHappens, née WJalopy > MontegoMan562 is a Capri RS Owner
04/24/2019 at 14:49

Dang son. Are they oil-injected or do you have to premix?

boredalways > MontegoMan562 is a Capri RS Owner
04/24/2019 at 18:25

Yikes!

Urambo Tauro > MontegoMan562 is a Capri RS Owner
04/24/2019 at 21:58

What kind of ratchet is that? I know I’ve seen that spiral shaft thing before, but I can’t remember what the mechanism is supposed to do.

MontegoMan562 is a Capri RS Owner > boredalways
04/25/2019 at 00:39

actually when I flipped it over I said - “WHAT THE FUCK!?” but “yikes!” will do in a pinch lol

MontegoMan562 is a Capri RS Owner > Urambo Tauro
04/25/2019 at 00:45

Nice spot! I was wondering if I’d get a comment on it. I love this ratchet -it’s a Craftsman Mach Series ! It has a fully swiveling head on it, and the handle has an option to lock it, or make the twist option function in forward or reverse. Say you’re pulling out a bolt. Set it to reverse, adjust the swivel so it’s similar to a “screwdriver style handle” then just push in, it’ll handle the action of twisting the ratchet for you and can basically do about 2.5 full turns in one inward push. It’s real handy, especially with some of these long threaded loc-tited bolts.

https://www.sears.com/craftsman-3-8-inch-drive-mach-series-ratchet/p-00944578000P?plpSellerId=Sears&prdNo=10&blockNo=10&blockType=G10

It’s been great for me and I think I got it as a gift, I can’t imagine spending almost $50 on a ratchet. I probably would have bought a harbor freight special if it was me doing the buying lol.

MontegoMan562 is a Capri RS Owner > ShrimpHappens, née WJalopy
04/25/2019 at 00:52

They are oil injected but I’m removing the oil injection and switching to pre-mix. On these older ski’s they have a tendency to completely at random have the oil pump die. The estimated time you have to notice the blinking *ENGINE OVERHEATING* light on the small screen is about 7 seconds. Which could very easily be missed while doing some sweet spinouts or a high speed run. If you don’t shut down in under 7 seconds...well your crankcase can look similar to the one I have. Not worth the ease of oil injection vs pre-mix.

If pre-mixing saves me an entire motor replacement you better believe I’ll be at the gas station with a god damn measuring cup if I need to be lol

Urambo Tauro > MontegoMan562 is a Capri RS Owner
04/25/2019 at 08:13

Neat! I have a Kobalt “Double Drive” ratchet that lets you turn fasteners by twist ing the handle back and fort h , but t hat pump-action ratchet might actually be faster.

MontegoMan562 is a Capri RS Owner > Urambo Tauro
04/25/2019 at 11:15

It’s a bit finicky because of the swivel head on it. When you get it lined up right it’s crazy fast. But at the same time it can be real annoying when you try and push in and the head on it flops over and it doesn’t do anything.

I suppose, just like anything it’s got good and bad.