[crazypete]

I just bought a 2008 vx cruiser with 15hrs. Took it out for it's first try out this weekend and found it to be slower than I expected. It runs at about 47 MPH...I thought maybe the speedo wasn't accurate but checked it with GPS and it's bang on..The research I did lead me to believe these did 53 mph consistantly. The only thing I see that might affect speed would be corrosion on the ride and intake plates.( I don't know if the corosion is normal or if it was exposed to salt water ) And would this affect top speed? The rpms appears to be ok and engine sounds good.

 

[Ernest T]

If it is reaching proper rpms (should be 8000), then the problem has to be in the pump. I'd take off the intake grate, and inspect the impeller and wear ring, especially if it has been used in salt water. Check the clearance between the impeller blades and the wear ring, and look for dings, or chips in the impeller.

 

[crazypete]

I did a quick check on impeller, looks nice (mild corrosion). After reviewing other posts on these vx models, I noticed my oil level was way too high, so I pulled the air box off and removed an oil soaked air filter and half quart of oil. I'll remove some oil and set it to the recomended level. I don't know if that will or could have slowed me down, but there was quite a bit of oil in the intake at the throttle plate. I'll put it back together and give it a try...see what that does...

 

[Ernest T]

You probably need to change the plugs also. That is the other thing over filling the oil tank does = foul the spark plugs.

Even 10% oil saturation of the air filter will reduce performance. You need a new filter, since the OEM one cannot be used after oil saturation. Look here for a better aftermarket replacement by R&D: ISLAND RACING

After all this, you should be getting near 8000 rpms and close to 52-53 mph.

 

[crazypete]

Thanks for info Ernest......Changed the plugs, changed the oil, filter as per specs from a yamaha assembly manual I found online. Cleaned complete intake and ran it without a filter as a test run.....got my 52-53 mph with my daughter on the back.....then tried it on my own for fun and saw 54 with a hint of 55mph...again thanks for your help Ernest!!!