300LX Spun Bearings - Root Cause

[boudin]

Very helpful. Thanks. For reference I see approx 60psi at idle when dead cold first start. But that drops way down to 25 when warmed up. Testament to letting an engine warm up before doing WOT.

-Greg

[boudin]

Update. I've run a full tank of fuel through and the ski is running well. 7450 RPM/14 PSI/64 mph on GPS.

I also ordered the CandooPro GPS module, which as I understand will also remove the limiter.

It's a really nice ski, strong acceleration and corning, pretty smooth in mild chop. Ski is super clean, freshwater and had <100 hours. It sure drinks fuel at full throttle!

What I did:

- Used 310 case and crank
- Used 300 rods (thanks @grumpy_stephen)
- New windage trays
- New rod bolts/nuts
- New piston rings
- New piston pin snap rings
- New main and rod bearings (plastiguaged)
- New supercharger belt
- Cleaned and spray tested injectors
- New supercharger intake pipe (flange was broken)
- Used exhaust manifold (due to broken bolt)
- Lapped all valves and checked valve lash
- All new gaskets
- Cleaned intercooler
- Tested oil pressure relief valve
- Tested oil cooler thermostat per shop manual
- Checked pump bearings
- New Iridium spark plugs
- New Odyssey PC625 battery and Battery Tender

Might keep this one for a while. Though, I let my buddy in the neighborhood ride it yesterday, and now he wants to buy it.

-Greg

[boudin]

Just a report at 10 hrs on rebuild. Running strong. Put in a rebuilt stock prop, and a CandooPro GPS module, calibrated in kph, and hitting 69 in 90+ degree water on a full tank of gas. Prop fixed a cavitation issue and ski pulls hard from a hole shot. Got to hold on!

I love it, but decided to put up for sale yesterday local here in Houston on CL. Got to make room for more project skis... almost done with a Yamaha XLT1200 MR1 conversion, and got another Yamaha SUV coming. Also got my '93 JS550SX running good.

-Greg

[dhmcfadin]

Just a report at 10 hrs on rebuild. Running strong. Put in a rebuilt stock prop, and a CandooPro GPS module, calibrated in kph, and hitting 69 in 90+ degree water on a full tank of gas. Prop fixed a cavitation issue and ski pulls hard from a hole shot. Got to hold on!

I love it, but decided to put up for sale yesterday local here in Houston on CL. Got to make room for more project skis... almost done with a Yamaha XLT1200 MR1 conversion, and got another Yamaha SUV coming. Also got my '93 JS550SX running good.

-Greg

Got a link to your CL ad? I’m in Austin, Texas.

[boudin]

Got a link to your CL ad? I’m in Austin, Texas.

PM Sent.