785 project - restoration work

[casey67]

I agree ^. I had one way-way worse. There are cleaning products that will take it off, but may leave discoloration, Being "stainless" that can also be cleaned with abrasive.

The heads are pretty thick everywhere, I have not seen any "damaged" by salt. Responsible owners do flush their machines.
The cylinders do get thin around the sleeve, I have seen those areas corroded away. Not sure what affect that would have as the thicker parts of cyl probably do all the support of the sleeve and the head works to keep sleeve in place.

As always, a couple pictures speak 1000 words. If corroded it will be visible.

[xlint89]

I concur. The SS pump will clean up fine. The bearings on the inside will most likely be garbage if the seals leaked. The spacer between the bearings would prob be the questionable piece if it saw salt.

I have decided salt water is not worth the hassle when buying used parts any more. The pump will be fine, but I'd pass on any engine parts personally.

[pascoea]

Well, the rebuild is off to a roaring start.

The washer from the High Speed Screw was air-mailed at light speed somewhere into the ether of my garage.

I don't suppose anyone has one of these they'd throw in an envelope for me?



Oh, and I screwed up on ordering the needles and seats. I have no clue what these are from, or how I goofed that one up... Top is new, bottom is OE. Close! Happy Monday.

[pascoea]

Oh, one other thing... Instructions (at least to me) are unclear.


Since I have the o-ring (Part 1a) on the pump body ("Late style Super BN 44") I omit the 2nd "Gasket, Pump" (Part #1), correct? That's how the carbs are set up now, but someone's been in them before, so I don't trust assembling them exactly as they are now. So the assembly stack goes: 18, 1, 2, 1a, 19a (assembled 4,3,19a,3,4), 5a, 6a?

[xlint89]

1. Washer. Do you have a GOOD hardware store near you? Will need a SS metric washer. If not, you can prob get a standard size and drill the hole to fit. Use 1 of the other carb washers as a a gauge.

2. Where did you buy those seats from? What's the receipt say? I'd send them back and get the Super BN 38/44 needle and seats you need.

3. If you have the O ring seals, follow the directions for the 38 and late 44 instructions.

[pascoea]

Thanks for the reply. I ended up finding a washer at the local powersports place, as for the seats I had ordered from https://www.speedaddicts.com, they let me return and re-order the correct ones.

As far as the carb question, I believe I understand. Below the pump body makes sense, I'm using the rubber seal (hate to call it an o-ring) instead of the paper gasket. Above the pump body, I'm omitting the 2nd gasket because they substituted the o-ring on later 44s. I think it's the "Not used on BN 38" comment next to my red arrow that is really what's throwing me off. Seems like it should say "Not used on BN 38 and Late BN 44"

[pascoea]

I finally made some progress!
Engine is re-assembled, I did the leakdown test but it's failing because the power-valves and wear ring aren't sealing. I believe I have the wear ring figured out, need a new o-ring, but what the heck do I do with the power valves? There doesn't appear to be any sort of seal, besides the bellows. Would a dollop of grease on the shaft do the trick?

[xlint89]

Power valves are not an air tight seal. Remove them from the engine and blank off the opening. Then try the test.

What wear ring are you referring to? The collar on the tail end of the crankshaft? There's an O ring between the crank and the collar. Then you have the collar sealed with the main rear seals. What's leaking there?

[pascoea]

Power valves are not an air tight seal. Remove them from the engine and blank off the opening. Then try the test.

Yeah, that's kind of what I figured, the whole "doesn't have a sealing mechanism" should have been a clue for me. I I'll give that a go, thank you.

What wear ring are you referring to? The collar on the tail end of the crankshaft? There's an O ring between the crank and the collar. Then you have the collar sealed with the main rear seals. What's leaking there?

That's the guy. I had forgot the o-ring on the prior test, so I think I've got that sorted. There wasn't a groove on the shaft where I was expecting, so I didn't think it needed the o-ring. And it had been so long since I disassembled I didn't remember taking one out of there. Live and learn, guess that's why we test.

[xlint89]

Absolutely. I wish everyone would do a leak down test after engine assembly. Would save a lot of headaches.

Many people replace pistons without figuring out why it failed. Then they fail again.

[pascoea]

Can I get some input on the stator? All of the readings are within the +/- 10% except the Pulser Coil. Supposed to be 90 (assuming the Pro stators are the same as the others) but it's testing at 22 ohms. Would that be enough difference for you guys to condemn the stator to a life of landfill duty?

I looked thru ebay for a replacement, but unsurprisingly came up empty. Any thoughts on where to source one? And I thought I had heard that the 750 or 780 stator/flywheel would be an acceptable alternative, is that accurate?

[Myself]

I don't ever condemn a stator on ohms alone UNLESS it's dead shorted to ground. Does it still produce a good AC voltage number while cranking? Around 20 VAC?
Maybe read through this thread..Troubleshooting Fuji 650 750 780 with no/intermittent spark - Greenhulk Personal Watercraft Performance Forums
I've been ALL OVER the Fuji electrical systems!

[sdlvx]

Don't ever condemn a stator. They can be rewound and a ton of things if they aren't right. Though it's hard to find someone who will do it and it's usually easer to get a new one.

[pascoea]

Don't ever condemn a stator. They can be rewound and a ton of things if they aren't right. Though it's hard to find someone who will do it and it's usually easer to get a new one.

Hmm. That's an interesting idea. I poked around a bit, this is one of the wrapped coils, so it wouldn't be SUPER hard to re-do.

[pascoea]

I don't ever condemn a stator on ohms alone UNLESS it's dead shorted to ground. Does it still produce a good AC voltage number while cranking? Around 20 VAC?
Maybe read through this thread..Troubleshooting Fuji 650 750 780 with no/intermittent spark - Greenhulk Personal Watercraft Performance Forums
I've been ALL OVER the Fuji electrical systems!

Thanks for the link. I'll take a look through that. (I tried going thru a similar link from the "Polaris knowledge" site, but they are all still busted since the GH update.)

I'll have to check the cranking voltage once I get this back together, the engine is still sitting naked on my bench. I assume I want the CDI hooked up when I do that test?