POSSIBLE PUMP DAMAGE

[CANGELOUS]

HOW DO I CHECK FOR POSSIBLE PUMP DAMAGE. SINCE I HAVE STARTED THE BOAT ON THE TRAILER. JET DRIVE IS A BERKELEY. MY MECHANICAL KNOWLEDGE IS LIMITED IN THIS SUBJECT..BOAT IS A 73 MARQUIS...HAVE KNOWN PREVIOUS 2 OWNERS AND JET HAS NEVER BEEN REBUILT...

[LVjetboy]

What happened? Any details?

[CANGELOUS]

NOTHING HAS HAPPENED YET THAT I KNOW OF, OR I AM NOT SEEING IT, READING THE INFO ON THESE FORUMS GETS ME A LITTLE SCARED THAT I COULD HAVE DONE DAMAGE BY STARTING THE BOAT ON THE TRAILER...BOAT MOVES OUT QUICK RUNS STRONG UPTO ABOUT 3100RPMS AND THEN IT SEEMS LIKE THERE IS A GOVERNOR ON IT....

[77charger]

i wouldnt think the pump would be your problem.Reason being is that if your pump is damaged you would be slow out of the hole or when you gas it it would feel like a slipping clutch.
Another indicator of a worn pump is it revs high and low top speed ex 5000 rpm to do 45mph.by starting it for a short time wont damage it but if you do this alot over time it would wear faster.if you have to start it get the hose and shoot water into the bowl and dont run it for a long time when i have to start mine for a timing adjustment this is what i do but for no longer than 30 secs.
the best way is to disconnect the drive line.

[Oldsquirt]

CANGELOUS, kind of doubt your problem is with the pump. Generally that will present as an engine that revs high but boat lacks speed, or serious noise issues from pump. It sounds more like you have a motor related issue. Two things to check. First, verify that the carburetor secondaries are opening properly. Second, check ignition timing, both at idle and around 3000 rpm. Secondaries that don't open or ignition timing that does not advance properly can cause a serious lack of power.
ps. ALL CAPS = yelling and are hard on the eyes(especially old ones http://free.***boat.net/ubb/smile.gif )

[CANGELOUS]

thanks for replies...now i have somewhere to look...the motor is a olds 455 bored .030, stock intake, quadrajet carb with vacuum secondaries, and a stock point ignition system, the motor was rebuilt ten years ago, but has less than 50hrs on it. I'm guessing the smart thing to do is put it back in the water the water to check the stuff you guys have mentioned out...I'm a new jet boater with a whole lot to learn.. thanks Can

[bp]

can, i agree with craig (oldsquirt), but i also feel that you should begin planning to have the pump rebuilt. you mentioned that the pump has NEVER been apart, and the boat is 29 years old (?). it's not a bad idea to pull the pump apart (or have a pro such as MPD do it) every few years or so. tolerances can become worn, impellers can become damaged, bowl vanes can become damaged, bearing can start to go, etc.. it's kind of like tuning up your engine. all this stuff can add up to lack of efficiency in varying degrees. get your engine running correctly, have fun with it, but don't forget the pump just 'cause the boat moves.

[Bense468]

How long was the boat sitting? I would check the carb and the throttle cables to see if you are getting full movement out of them. Oh and starting your boat on the trailer every once in a while is not your prob. Good luck.