performance loader grate question????

[HotDogz]

Does a performance loader reduce your rpm's by loading the pump more?
My 455 is only spinning 5000 rpm's with a Berk 12JC-B level II fresh build and loader. I'm thinking I should be able to spin to 5500 rpm's. Motor is fresh and built "professionally and correctly" with all OLDS issues addressed.

[Rexone]

Does a performance loader reduce your rpm's by loading the pump more?
My 455 is only spinning 5000 rpm's with a Berk 12JC-B level II fresh build and loader. I'm thinking I should be able to spin to 5500 rpm's. Motor is fresh and built "professionally and correctly" with all OLDS issues addressed.
Depending on what degree it was ineffecient in loading without a loader, yes it can and will reduce rpm, as a general statement.... every boat is a little different as a disclaimer.
5000 with a tight pump and loader is a reasonable number for a good running olds. You should be examining differences in boat speed at the present 5000 rpm vs boat speed before the pump was done and the loader was added. That is where you should see a difference even with new reduced rpm.

[ARS Marine inc. east]

HotDogz:
I just happened to remeber seeing this on the American Turbine Site And Thought it may Help you in some Kind Of way Or another.
UNDERSTANDING YOUR JET BOAT
Most boat owners like to perform at least a certain amount of their boat maintenance themselves to ensure continuing good performance and reliability.
To avoid unnecessary trips to the service center, it might be useful to have a checklist which can be run through systematically, in the hope of pinpointing the problem quickly. The boat can be divided into three categories - jet unit, engine, and hull.
If something is "wrong" with the boat it is usually poor acceleration and load carrying, coupled with excessive fuel consumption or engine RPM's. It could be unusual noise coming from the mechanicals, or possibly just poor top speed. All of these things may be present to some degree, but the usual complaint is that the boat is just plain "gutless".
TACHOMETER
The most important single instrument on the boat when considering performance drop-off is the engine tachometer. The great thing about jet boats is that the engine RPM's should remain the same throughout the life of the boat, regardless of age, loading, water conditions, towing, whatever.
There is no situation where the RPM's should be different from when the boat was new, and as an owner, you will know what these are. At any time, you should be able to open the throttle fully and get exactly the same maximum reading you have been used to. Or perhaps you are finding it needs more RPM's to cruise your normal load? RPM's are a most important indicator of proper operation of the boat.
It is important at this stage to feel confident that your tachometer is reading accurately.
Now we come to our check list, and determination of which major area is the problem. The simplest way is a check on the RPM's first. They could be normal, high, or low, and this will pin point the place to look:
C. Low RPM = engine problem
There is generally no way the jet unit can overload the engine and bring the RPM's down. If the RPM's are down from usual, it is almost certain to be a engine problem. A compression check will usually reveal leaking piston rings or valves, but the most common reasons for reduced engine power are:
1. Throttle: Check that the throttle is opening fully.
2. Fuel: The fuel supply must be adequate for the engine size. Racing boats frequently have a fuel pressure gauge which is, with the tachometer, probably the most important engine instrument. Sufficient fuel must be reaching the engine.
3. Air to the engine: The carburetor must be getting its full quota of cool air. If the engine has to work to get adequate air, and if it is hot air, this will reduce power.
4. Ignition spark: Be satisfied the ignition system is operating properly. A problem here is usually indicated by a rough running or missing engine.
5. Exhaust: Check for a free flowing exhaust system. Some silencers can become blocked, rubber hoses disintegrate internally, or there is excessive water injection. Such things can cause excessive back pressure and reduce power.
Provided your engine is getting its full quota of air and fuel, and is getting enough spark and at the right time, the engine will usually be OK, and maximum RPM's will result. However if the RPM's are down and you believe the tachometer, look for an engine problem.
HotDogz: I had the Same Problem With a Boat once Went Thru the Pump And Changed The Loader Tested it, And the RPM's Where about 400 less and it wound up Being float the had a pin hole in it , So it took in a little Fuel Then Sealed it self back up . "To this day I still have that Float with the Fuel In It"

[HotDogz]

I really appreciate your guys's input. This is our first boat and alot of work has gone into it and sometimes I just have no idea what to expect for performance. Before the jet rebuild, made 4800-4900 rpm w/no loader and tired motor and made 58-59mph. New loader and made 63mph. Rebuilt the motor and pump, now I make 5000rpm @65. expected more. Someday maybe 75
Thanks for your input...