Going to look at a 787 engine tomorrow, any tips?

[travial]

Hey guys, been lurking around the forum for the last couple weeks, good stuff here. I just bought a 1997 GTX (came with a shuttle craft), w/ carbed 787 engine. The guy said it just needed a MAG piston, and me knowing jack squat about jet skis believed him and bought the thing. He was right, the Piston is destroyed...along with the crankshaft and connecting rod bearings.

Anyway, I found someone here in town who selling most of a 787 engine for $200. He said it got a little water in it, but the crankcase looks good, and it just needs rings for the 1mm over-bored cylinders and a couple gaskets. Cylinders are currently off the block. He also kept raving about some $500 Hotrod crankshaft in it, whoopee. Either way, $200 seems like a good deal, so on to my question:

When I go look at it tomorrow is there anything I should look at specifically? I am worried about the crankshaft bearings, especially if he said it got some water in it, although he claims it looks nice in there and the bearings spin smoothly. Are there any tests that I can do on it or things to look at to determine if it's a good crankshaft or not? Any other tips/tricks about looking at a used engine? Thanks in advance!

 

[GGuillot]

How do the cases look on your engine? I'm not sure I'd trust spending $200 on an engine/crank that got water in it. What are you gaining? What's the engine coming out of? There's an RFI version of the 787. There's no way of guaranteeing anything that crank is still good. I faced the same situation rebuilding my 97' GTX last year, it was completely trashed when I got it. PO had a poor rebuild done with an untrimmed RAVE that put a side hole in a piston and locked the motor, which filled with water and sat for over a year in barn. I searched out for parts to rebuild it, top end, reman crank and balance shaft, gasket set, and machined RV cover. I spent just under a $1000.

 

[travial]

I haven't cold my engine out yet to look in the cases, but just from looking in the intake Port they look clean, with the exception of some nicks and scrapes on the MAG connecting rod where something has gotten loose in there and scored it. I'll be trying to Frankenstein this thing back into the water spending as little as necessary, and the engine's only 10 minutes away, so I'll take a stab at it. He says the cylinders/pistons are good so I may just be able to use the top end and save myself a re-bore and pistons on mine. I'm about to go look at it, I'll come back and post some pictures either way.

 

[mikidymac]

If the crank got any water in it and sat it is junk. Also the Hot Rods cranks are known to be poor quality.

You can get a new OEM crank for $300 and send your cylinders out to fullbore for $325. Or just buy and entire engine with warranty from SBT for $900. I wouldn't buy someone else's used crap.

 

[KyleW2]

If it were me, I would just buy a reman engine, buy once cry once, then have a blast all summer on a great running ski. But I completely understand wanting to get it done as cheap as possible. I agree with the above though about spending a lot on a watered down crank. Proceed with caution

 

[travial]

Thanks for the advice guys. I'll keep you updated.

 

[travial]

Well, I pulled the trigger on it. He said he pulled it from a ski with electrical problems. The crank felt smooth, and the crankcase, pistons, and cylinders looked good (they were only .5mm over). And only paid $150 for everything. I figured worst case I can part it out for more than that, but I think I'm gonna use it. What do you guys think?!

 

[GGuillot]

Well, I pulled the trigger on it. He said he pulled it from a ski with electrical problems. The crank felt smooth, and the crankcase, pistons, and cylinders looked good (they were only .5mm over). And only paid $150 for everything. I figured worst case I can part it out for more than that, but I think I'm gonna use it. What do you guys think?!

Personally, I wouldn't run it in my ski, it's a recipe for getting stuck on the lake. To me at $150 you basically got a couple good spare cases and maybe decent rotary valve and balance shaft. Alternatively, flipping that engine for more $$ in parts isn't realistic. At a minimum I'd swap the crank for a new OEM or reman, new top end, new gasket set etc. And if you want no issues after doing that, rebuild carbs to OEM, ck the RV spec, go through the jet pump the fuel system, new lines, etc.

Couple thoughts, it had water in it, how long will the crank survive? When you get it together as is what do you think the compression will be? What if it's low?

Rebuild it like it needs to be done and you'll have a lot of fun on the water this season, cut corners and you'll become frustrated and in the long run pulling it and doing it over anyway.