787 crankshaft question

[drev500]

Sorry guys if this is in the wrong section but question about a 787 engine out of a 1998 speedster. The guy I bought the boat off of said he "rebuilt" the starboard engine but got too busy to install it. I got a pretty good deal on the boat so I didn't bother to check it but he did say he used a new crankshaft.

Fast forward, I install the engine but oil is filling up #1 cylinder. Well I strip it apart and do see freshly honed cylinders (1.00mm oversized) but I can not tell if the crank seals are issue and I can't determine if the crank is a rebuild or the old one. Anyone have any ideas what is going on? Im thinking of just throwing a new crankshaft in since I already have it apart.

Thanks

 

[Ankeneyou]

Sounds like crank seals to me. I talked to that guy a few times since last October but he always wanted too much. Started off at 4k, 3800, 3500, so I bought one out of Nebraska. Last I saw he had it on CL asking 2500.

 

[racerxxx]

That's not a new crank

 

[Ankeneyou]

Also it looks like tcw3 oil in the bottom of the cases. You should be running API-TC.

 

[drev500]

Haha small world. Yes I ended up getting it for less than that so I thought it was an alright deal. It has been a fun project but I should have been a little more vigilant. I was a bit eager for a project. The guy said he fired up the port engine but there's no way. Both sets of carbs were packed full of gel. Rebuilt all them and now port engine is running great... out of water (we'll see what the water test says).

Good call on the oil. There was a bit left in the tank. I should have drained and started fresh. I also threw some Pennzoil XLF I had from a Yamaha jet boat I built. Didn't know the Seadoo's call for API-TC. Is there a preference?

 

[Ankeneyou]

Yeah I was the same with mine but there weren't many options when I needed to start my project. I've got a thread on my resto/build but its been slow with work travel. I ended up getting a 2nd boat at an auction with a damaged hull just for parts.

As for oil any low ash api-tc. The seadoo XPS oil is good stuff but it's about $46 a gallon on amazon. I started using Mystic JT4 full synthetic I order by the case of 4 directly from the manufacturer and it's about $33 a gallon shipped.

 

[jjsinaz]

That's not a new crank

Just for my own education, how can you tell that's not a new crank

 

[racerxxx]

Just for my own education, how can you tell that's not a new crank

the rods sound be brand new copper color. The snout where the flywheel goes is filthy, a rebuilt crank it would be spotless. The bearings habe a radial grease line around them from years in use. The webs of the crank show signs of rust, they would be spotless on a reman crank. Look in my XP, XP 800 or SPX build threads, those are reman cranks.

 

[Ankeneyou]

Here is an OEM reman crank.

 

[Matt Braley]

Here is an OEM reman crank.

Can I just have that? :hat: They just don't pop up on ebay often enough

 

[jjsinaz]

Thanks guys. Good info.

 

[drev500]

Jjsinaz, here's a side by side of the old and new. SBT rebuild not as pretty as the OEM reman above.

 

[mikidymac]

The SBT doesn't use the "new" red seals, OEM bearings and they are welded so nobody else will take them as a core.
I haven't heard of them failing but they definitely are not OEM equivalent.

 

[racerxxx]

The SBT doesn't use the "new" red seals, OEM bearings and they are welded so nobody else will take them as a core.
I haven't heard of them failing but they definitely are not OEM equivalent.

DOn't know how closely you look at your OEM remans, but I know the ones I have bought all look like new everything......everything. I 've yet to have one that looks like any web was ever used before.

 

[mikidymac]

I agree the OEM ones look amazing. I have a brand new 720 one sitting in the garage.

Their shipping boxes are awesome too.

I was saying the SBT's were not the same as OEM. That being said though, I can't say I have personally seen an SBT one fail.
I know with shipping to and from California the $279 SBT cranks are more expensive than OEM.

 

[racerxxx]

If you add in the shipping to and from OEM from your local dealer might even be cheaper. But, everyone looks at the up front cost.

 

[mikidymac]

If you add in the shipping to and from OEM from your local dealer might even be cheaper. But, everyone looks at the up front cost.

That is what I just said Racer. LOL. I think we are saying the exact same thing [emoji3]

 

[racerxxx]

That is what I just said Racer. LOL. I think we are saying the exact same thing [emoji3]

Hey, it was late and I was tired