SoCal Jet Boats
Tech Talk => Jet Pumps => Topic started by: eric69cam on February 11, 2011, 07:23:11 PM
-
It appears i need to replace the input shaft seal on the Berk JG in my Sleekcraft Exec before the season gets under way. i believe it is the rope seal tpe.
How difficult is this to do?
Is there anything else i should replace in regards to maintenance while it is out? As far as i know, the pump is original, the boat is a 1976 model year.
-
If the pump is 35 years old it should at least be rebuilt. Search the tech section on here for info on rebuilding it, can be DIY or can send/take to Jet Boat Performance for a rebuild.
If you cant find the info your looking for by searching the tech section, call JBP at (805) 466-4719 and they can get you all the parts you need and even walk you through the process.
-
If the pump is 35 years old it should at least be rebuilt. Search the tech section on here for info on rebuilding it, can be DIY or can send/take to Jet Boat Performance for a rebuild.
If you cant find the info your looking for by searching the tech section, call JBP at (805) 466-4719 and they can get you all the parts you need and even walk you through the process.
Jeremy - Tom and guys at JBP are great and all, but whats the point of having this forum if everyone just calls them for advice.
Eric, if you have any questions, feel free to ask here. There is a TON of knowledge here on the site and everyone is eager to help out. Dont be shy to even ask simple questions. we were all there at some point.
The Packing rope replacement is not that tough of a job, just might be a lot of work if you need to pull the pump and/or motor to get to it. As far as any other work - how is it performing? The Exec is a big boat. does it come out of the hole decent? Why are you wanting to replace the packing rope? is it just leaking?
-Brad
-
A rebuld is out of the question for now. No funding available.
I was wanting to replace the seal because it has a steady leak. Moreso at rest than actually running. I tried adjusting the compression flange by turning the 2 bolts 1/4 turn each. That seemed to slow it down some but didnt fix it. Another concern i had was a noise issue. There is a rough, almost clunking noise audible at idle and low rpms. It subsides when it has been freshly greased; it has a grease port directly behind the input shaft seals.
The boat runs pretty good really. It has a place diverter and trim tabs. If the diverter is in the right position as well as the trim tabs, I can launch very well compared to my Dads exec which has a Jacuzzi/dominator with fixed nozzle. I havent been able to confirm my best top speed as i dont have a GPS...
-
The clunking noise I would be concerned about. It could be your thrust bearing going bad. Also, it might be your drive shaft. Is there grease zerks on your drive shaft? if so, pump some grease into that.
Is the pump out of the boat? do you plan on removing it to do this maintenance?
-
A rebuld is out of the question for now. No funding available.
I was wanting to replace the seal because it has a steady leak. Moreso at rest than actually running. I tried adjusting the compression flange by turning the 2 bolts 1/4 turn each. That seemed to slow it down some but didnt fix it. Another concern i had was a noise issue. There is a rough, almost clunking noise audible at idle and low rpms. It subsides when it has been freshly greased; it has a grease port directly behind the input shaft seals.
Not trying to spend your money, quite the contrary really.
Spend the bucks on a gasket kit, seal kit, rope seal, bowl bushings and a thrust bearing. This would be enough parts to at least keep it from destroying itself until you get the funds together to do it up proper. Not to mention allow you to enjoy it for the season.
If the thrust bearing fails, it has the potential to take out the rear thrust bearing of the engine.
What you have sounds like it could be a pitted thrust bearing, could very well just be a u joint or a loose fitting splined shaft, sort of hard to say.
If you need moral support, this is the right place... :thumbup:
I have a lot of good used parts, and some new, let me know if I can help. 8)
GT
-
Step one is to determine what is causing the noise.....it might be the typical low rpm "pump rattle" and it might be a sign of something going south. The fact that adding fresh grease makes the noise stop indicates one of two things....either the noise is i'n the bearing, or the bearing is worn out (but quiet) and when it's flopping around, the shaft is moving causing the impeller to contact the housing...adding grease takes up space and temporarily tightens up the bearing.
Regardless, I would tear it down and see what's going on.
It's really not to hard to replace all the parts. short version: pull the bowl, pull the impeller, remove rope seal, unbolt front bearing cap, smack shaft forward with a soft mallet and pull the shaft/bearing assembly out the front. Remove old bearing, press on new, installation is reverse of disassembly.
The hard part arrives when attempting to "blueprint" the pump.....ideal radial clearance between the impeller and wear ring is .025", and if using a shouldered wear ring you've got to shim the impeller back to set that clearance as well.....when the thrust bearing comes under load, it deflects and the shaft/impeller will walk forward a bit....need clearance so it does't hit. I generally buy an undersized wear ring and standard size impeller and re-machine the impeller while on the shaft to control the runout of the assembly....this is a procedure skipped by some shops that I feel is probably most important for pump performance and longevity.
If money is tight...don't worry about the impeller or wear ring for the time being....just do the gaskets, thrust bearing, and bowl bushings.....that will keep the rest of it alive until you're ready to do the rest of it.
Start with pulling the bowl and impeller, take it from there. Disconnect the driveline and the while applying forward pressure to the shaft, spin it and feel for any rough spots....if there at any, change the bearing.
-
The clunking noise I would be concerned about. It could be your thrust bearing going bad. Also, it might be your drive shaft. Is there grease zerks on your drive shaft? if so, pump some grease into that.
Is the pump out of the boat? do you plan on removing it to do this maintenance?
I believe there are zerks in the u-joints. The pump is not out. I am not opposed to removing the pump to do some of this mintenance. If i end up doing more intensive maintenance than just the rope seal (thrust nearing, gasket kit...) can this all be done without removing the motor? I am not equipped for doing that. No cherry picker.
Anybody have a link to a specific parts kit that would include the seals, rope gasket, thrust bearing(s) for 12JG? Or resources for step by step instructions for nozzle, bowl, shaft removal... Any specialty tools required?
-
Here is a link to CP's site that lists a few different levels of rebuild kits. Depends on how much you want to rebuild it.
http://www.cpperformance.com/c-676-rebuild-overhaul-kits.aspx (http://www.cpperformance.com/c-676-rebuild-overhaul-kits.aspx)
The first one comes with everything.....the whole sha-bang-a-bang. impeller, thrust bearing, all the seals, n stuff.
the 2nd is the same just minus the impeller....but still has the thrust bearing which we believe you might need.
the 3rd is just the seals n stuff.
I suggest pulling the pump and seeing what all you need before buying a kit so you do over/under buy what you need.
You can pull the pump without pulling the motor. it will just be tough to get to some of the bolts that hold the suction housing to the intake. just pull the transom adapter and unbolt the suction housing and it will slide out the back.
-
Alright guys, been a busy day. So the pump is out now. 8)
Bowl is off and bearing cap is off. :thumbup:
Now in order to remove the shaft, the impeller has to come off, is a pipe wrench, for holding the shaft in place, really acceptable for this job? ???
Any advice on removing all the stubborn gasket material on the intake mating surfaces, transom?
Is a wire wheel safe for the pump surfaces, obviously not for the transom..?
-
Thats what I used....umm er what I should say I tried to use. I ended up cutting the nut off...never could break it, toasted the shaft doin it :banghead: I hope you have better luck that I did. :beer:
-
The little red 3m scotch brite disc that go in the end of a drill take the old gasket off the pumps mating surface great. Had the same issue when I pulled mine apart.
-
Thanks! I've got all the pump surfaces cleaned up reall well via a wire wheel and die grinder. Im a little concerned now about the transom, dont want to scuff that up...
Aside from that, i should be able to get the impeller, and shaft pulled out tomorrow at work.
Are the edges of the impeller facing the thrust bearing the ones that need to be sharpened upon a rebuild? Mine are pretty chewed up. The edges facing the nozzle end are nice and sharp, straight edges...
-
Are the edges of the impeller facing the thrust bearing the ones that need to be sharpened upon a rebuild? Mine are pretty chewed up. The edges facing the nozzle end are nice and sharp, straight edges...
Depending on "how chewed up" they are if very much is required to clean them up , your better off to find a good used, repaired or new impeller removing very much material could disturb the balance and also change the dynamics of the impeller Tom
-
ok guys. Since this has turned into a full rebuild, i'm looking at trying to add a little pep to it.
My question is this...
Of the following, which offers the best bang-buck gain for a larger 23' daycruiser with 460BBF?
- Inducer
- Bowl Stuffer
- SS Pre-Loader
-
ok guys. Since this has turned into a full rebuild, i'm looking at trying to add a little pep to it.
My question is this...
Of the following, which offers the best bang-buck gain for a larger 23' daycruiser with 460BBF?
- Inducer
- Bowl Stuffer
- SS Pre-Loader
give the pump a blueprint and one of JBP's (i think) new clean out covers to reduce cavitation.
-
Bang for the buck on yours is wear ring, and inducer. You can detail the leading edge of the impeller back like it was by yourself, just remove the burrs on the leading edge, don't try to grind out the bigger nicks, for your deal they aren't important. The balance won't be affected by enough to care as long as you keep the grinding and sanding fairly even from blade to blade. If you really need to balance it we can do it while you wait. Our machine will do it to .1 gram, most stock impellers aren't within 6-8 grams. The heavy boat loves the inducer! Lower cruise rpm, better hole shot, same top end, all good. Most pump shops, us included, will machine and keyway the shaft for free with the purchase of the inducer. At that time we cut and polish the rope seal surface true too. The rope seal surface on the shaft doesn't tend too wear evenly, if it isn't TRUED and polished, when the new rope seal is installed, it will wear the rope quickly. With the inducer sale, that will be free too. Call if you need more free info. TIMINATOR
-
Bang for the buck on yours is wear ring, and inducer. You can detail the leading edge of the impeller back like it was by yourself, just remove the burrs on the leading edge, don't try to grind out the bigger nicks, for your deal they aren't important. The balance won't be affected by enough to care as long as you keep the grinding and sanding fairly even from blade to blade. If you really need to balance it we can do it while you wait. Our machine will do it to .1 gram, most stock impellers aren't within 6-8 grams. The heavy boat loves the inducer! Lower cruise rpm, better hole shot, same top end, all good. Most pump shops, us included, will machine and keyway the shaft for free with the purchase of the inducer. At that time we cut and polish the rope seal surface true too. The rope seal surface on the shaft doesn't tend too wear evenly, if it isn't TRUED and polished, when the new rope seal is installed, it will wear the rope quickly. With the inducer sale, that will be free too. Call if you need more free info. TIMINATOR
Thanks a lot for the info! I am looking into trying to get an inducer ASAP as that appears to be what i'd like to do. My question now is this;
Considering the size of my boat and the stock 460, can i gain ENOUGH from an inducer in hole shot, to go with a B impeller to gain in top speed or cruise MPH?
Currently, my boat cruises at approx. 50 +/- 5MPH @ 4800RPM. What kind of MPH increase is realistic from a B impeller?
I'd love to be able to hit 60+ topped out BUT I/we ski way too much to sacrifice that capability.
-
I have an inducer coming for you! Only got that arranged late, and didn't want to bother you then. As far as cutting the impeller to an AB or B, lets have a look at it first to make sure there are no other issues. Bring it with the rest of your stuff. Also, bring your distributor, we won't charge you to put it on the machine and check to make sure that it still has the correct amount of advance. Lack of internal advance can cause low full throttle rpm. The inducer will allow cutting the impeller for more RPM without losing holeshot/ ski ability. We are here till 6:00, or we can wait for you if you need us to. We are also here Saturday from 9:00-1:00. TIMINATOR