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I'm thinkin that my ATJ pump is ready for a refresh... It was originally completely set up by Tom Papp with an A/B impeller but it's got ~ 120hrs on it now and i'm noticing quite a bit of lag out of the hole or when pulling up a slalom skier (Is 120 hrs a lot?).
Is this a 'Do It Yourself' project or should I have it done? I'm fairly handy w/ a wrench but I don't have gobs of free time on my hands. Also, any quality performance minded shops in the Bay Area that you'd recommend?
Thanks!
bump.....any input on rebuilding my ATJ?
I hate to pay people. So I rebuilt my pump myself. Its not a rocket, so you don't have to be a rocket scientist to work on it. You can find pump info on AT website. You will need many hrs of free time for you first rebuild. Then you need the tools to work on the pump. A hydraulic press is needed to replace the thrust bearing. You will also need a wrench or socket to R&R the impeller nut and a puller to remove the impeller. I made my impeller socket and puller. Other shop tools like snap ring pliers, seal driver set, cut off tool, thread chaser set, feeler gauges and a dial caliper are needed. You also need to check the shaft for run out with a dial indicator while turning the shaft in a lathe or on v-blocks.
If all that sounds like too much and you don't have the time to spend working on the pump, pay some one.
bump.....any input on rebuilding my ATJ?
Go check out http://www.jetboatperformance.com and then email or call Tom. He's got to be one of the coolest people going and willing to help even if there isn't a buck in it for him. The man is TECH SUPPORT at it's BEST!!!
Talk to Dave Bostrom at "GT Boats" in cordellia. He has always been good to me and does good work and wont cost you big$ he is very fair and has lots of experiance with race pumps
If you are in the San Jose/South Bay area, there is also Glenn at Pleasure Boat Specialties.
Before you go condemning the pump as the cause of your performance drop, could you be more specific regarding this "lag" you are referring to? Is it a case of A.) engine accelerates easily but boat does not(kind of like a slipping clutch), or B.) engine does not accelerate easily(feels sluggish) and boat performs poorly as a result? Case A would point to a loose/worn pump and case B would point towards engine related issues. Since I saw you recently spent some time at Shasta, hopefully you are not comparing performance at that altitude and temperature to how the boat runs down near sea level and in cooler weather.
As for whether 120 hours is a lot......all depends on where and how it is run. Big deep lakes are much easier on the pump then shallow, silty, sandy rivers/lakes.
If you are in the San Jose/South Bay area, there is also Glenn at Pleasure Boat Specialties.
Before you go condemning the pump as the cause of your performance drop, could you be more specific regarding this "lag" you are referring to? Is it a case of A.) engine accelerates easily but boat does not(kind of like a slipping clutch), or B.) engine does not accelerate easily(feels sluggish) and boat performs poorly as a result? Case A would point to a loose/worn pump and case B would point towards engine related issues. Since I saw you recently spent some time at Shasta, hopefully you are not comparing performance at that altitude and temperature to how the boat runs down near sea level and in cooler weather.
As for whether 120 hours is a lot......all depends on where and how it is run. Big deep lakes are much easier on the pump then shallow, silty, sandy rivers/lakes.
Very Good Information ... Tom
If you are in the San Jose/South Bay area, there is also Glenn at Pleasure Boat Specialties.
Before you go condemning the pump as the cause of your performance drop, could you be more specific regarding this "lag" you are referring to? Is it a case of A.) engine accelerates easily but boat does not(kind of like a slipping clutch), or B.) engine does not accelerate easily(feels sluggish) and boat performs poorly as a result? Case A would point to a loose/worn pump and case B would point towards engine related issues. Since I saw you recently spent some time at Shasta, hopefully you are not comparing performance at that altitude and temperature to how the boat runs down near sea level and in cooler weather.
As for whether 120 hours is a lot......all depends on where and how it is run. Big deep lakes are much easier on the pump then shallow, silty, sandy rivers/lakes.
You make some good points... I would characterize the symtoms as you describe as 'case A.' but it is a bit complicated by the fact that the motor hasn't been running quite up to snuff combined with the Shasta environment . The boat has spent 100 of the 120 hours at Anderson in Morgan Hill so silt is not a factor but it is a pretty heavy 21' foot boat with a pretty stout motor. Given that, is 120+ hrs ' a lot' of hours?
My berk "F" was was really worn out. I didnt know how badly until it was torn apart, but even so, I have no doubts it woulda pulled a skiers arms outta their sockets if I nailed it. Granted, my boat is smaller (16ft) If the engine hasnt been running for awhile, I'd make sure that it is in good tune. 120 hours doesnt sound like very many too me at all. Probly wouldnt hurt to pull it (jet) apart and inspect things though...