sucked in some rocks ruin pump????

[Firewireal]

Hello everyone; New to this site. I have a question? I been the owner of a 73 jersey jet boat for about two years now. it has a olds 455 slightly modded with a Jacuzzi YJ pump. Ran great up until a couple of weeks ago when we were at the lake and beached for lunch. Buddy decided to take the boat for a spin while I was visting a shrub and started the engine in very shallow water, threw it in reverse and back out from the cove. When I say shallow i mean the hull was resting on the lake bottom in its entirity. Anyway the pump stired up alot of rocks and lake bed junk that was sucked into the pump. he got past the 5mile bouys and floored it. lots of rpm and no go. he shut it down and we had to go rescue him. got it on the trailer and looked up into the grate and found alot of large rocks wedged in. Got those removed and headed home for the day. Today we took her back out and now the boat will produce plenty of power but only travel at about 9 miles an hour (GPS). Got her back to the trailer and home pulled the rock grate off and found several more rockes wedged in the impeller vanes. removed them and checked the impeller for crackes and what not. all looks okay. Could I be looking over something or would the rocks have cause the decrease in speed and performance. We have a trip to the lake planned again for this weekend, should I chance it; that that was the problem, or wait to have it checked out. Any help Please. Thanks

[RotorRider]

If you have checked impeller for any damage or cracks, and have completely checked inside and outside of the rest of the pump for more rocks being lodged inside or other damage, I would try a very cautious start and run, at any sign of things not being right, vibration, etc. shut down, then you will probably have to bite the bullet.
I'm thinking that the impeller being stuffed with rocks and crap pretty well shut down the flow, but may have not caused any real damage.
Check everything really well first !! :cheers:

[BIGA]

possible that you could have debris behind the impellor stuck in the bowl. any debris will greatly affect the performance. you may have to remove the bowl to be sure.:confused:

[Firewireal]

Thanks for the replys, I check every thing pretty well though the inspection hatch and the grate. Nothing looks sheared or chewed up, but I havent removed the bowl yet either. I was thinking if there is debris (rocks) aft of the impeller would that cause a vibration or rattling noise? Just trying to get lucky here. Is removing the bowl a extensive job, or is it something that should be left to the professionals. What Items am I looking to replace if I split the unit all all is good? I mean like any seals or bearings? I been a mechanic for 28 year with the military, but that was on Helicopters. This is a different beast.

[Firewireal]

Hey I was looking at the parts digrams for a Jacuzzi YJ and they don't resemble what I have. here is a pic of the drive I have. Any help on the type?? Thanks

[thompy]

the toughest part on the yj for me was rear cover sealed to the transom, and the o-ring sealing it did rip, just superglued it back together

[Tom@JBP]

Al this jet is fairly simple to work on /repair and the Impeller is relativley tough (stainless OEM) Like said probably the toughest part is pulling the transom adaptor and a caution here, if you don't pull the transon first adaptor you can very likley break the back of the suction casting (two back bolts) . odds are your rock dredging did no real harm , Good idea to pull it apart and "freshen" the jet . The performance can be enhanced on this jet with a few minor tricks Good luck Tom

[thompy]

its looks like a wj, much better than the yj

[Tom@JBP]

its looks like a wj, much better than the yj

thompy the two basic Jacuzzi designs actually both work well for what they were designed for in thier original states , the YJ just does not lend itself to performance mods nor does it like/respond well to big power Tom

[Last Mohican]

Hey I was looking at the parts digrams for a Jacuzzi YJ and they don't resemble what I have. here is a pic of the drive I have. Any help on the type?? Thanks

That is a WJ.

http://forums.screamandfly.com/forums/attachment.php?attachmentid=198228&d=1270825968

[Rivernut]

Rocks or wood in the bowl or grate cause cavitation, usually bad vibration too. If I have junk in mine it often won't get on plane or barely does and loses speed. No harm done, just using a jet in shallow water as they were intended. I have run through gravel bars that were exposed and smashed big rocks and never hurt my impeller enough to have a reduction in speed, just small nicks. I assume you have a stainless steel impeller. It should be fine. Don't worry about a mechanic or a rebuild, that's way overkill for a simple scenario like this. Get out and get on it!

[thompy]

wj is jacuzzis high pressure pump

[Just A Jet]

My dad is 71 this year and has been jet boating for over 10 years..
He has sucked me chit in his pump than????I always knock them out and back in the water(most of the time on the same day!)
I have sucked up a few things myself..I sucked a piece of a branch about 3 in long and 1/2 around it got wedged in my loader running down the river and the boat just slowed down at the same RPM until it quit? Pulled it out and it was fine. Hard to think that something that small can do that???But the water can't flow with the rocks in there.

[Tom@JBP]

I'm not going to disagree that a jet can't take the injestion of rocks and gravel and shake it off but with all of us being critical about our performance and most looking for that extra little bit , rock damage can and will scrub off speed and performance ,had the cam on the wrong setting and will retake and repost when time permits but heres a couple examples from this past week alone Tom
http://i147.photobucket.com/albums/r319/jetboatperformance/2010%20misc/DSC08414.jpg

[Firewireal]

Well guys took the Ol' Jet to the lake this morning with alot of prayer and what I learned from all of you. The drive preformed better than it has in a long time. Good hole shot, good speed performance, had fun for the first three runs. Then Murphy's law stepped in and screwed things up. Fourth run started great; was running at around 3800 rpm, 46lbs oil, temp was about 140 to 160 at that speed and the water was really cold. Noticed a low freq vibe about 15-20 min into the run, rpms dropped to 3500 and picked back up again; then looked back and the engine was smoking from the valve cover breathers. Shut it down right away thinking I just blew the engine; temp soared to 250. So there we sat letting it cool off and wondering what happened?? After a half hour or so checked the oil to see if it had water in the oil and to my suprise there was no oil (and no water). Had some oil with me put three quarts in and gave her a try started right up and then died, several times and I gave up. Got a tow back to the dock, trailered and started messing with it and looking around. Lots of oil in the hull sump. Blown rear seal as far as I could tell. So looks like I get the fun task of pulling the engine and replacing at least that seal. Is there anything else that anyone can think of to check for as well because of the starting and dieing right away. I think I might have spun a bearing as well (low freq vibe)??? Any thoughts???

[Just A Jet]

Well guys took the Ol' Jet to the lake this morning with alot of prayer and what I learned from all of you. The drive preformed better than it has in a long time. Good hole shot, good speed performance, had fun for the first three runs. Then Murphy's law stepped in and screwed things up. Fourth run started great; was running at around 3800 rpm, 46lbs oil, temp was about 140 to 160 at that speed and the water was really cold. Noticed a low freq vibe about 15-20 min into the run, rpms dropped to 3500 and picked back up again; then looked back and the engine was smoking from the valve cover breathers. Shut it down right away thinking I just blew the engine; temp soared to 250. So there we sat letting it cool off and wondering what happened?? After a half hour or so checked the oil to see if it had water in the oil and to my suprise there was no oil (and no water). Had some oil with me put three quarts in and gave her a try started right up and then died, several times and I gave up. Got a tow back to the dock, trailered and started messing with it and looking around. Lots of oil in the hull sump. Blown rear seal as far as I could tell. So looks like I get the fun task of pulling the engine and replacing at least that seal. Is there anything else that anyone can think of to check for as well because of the starting and dieing right away. I think I might have spun a bearing as well (low freq vibe)??? Any thoughts???

Not to be a smart ass, but oil is a +... run her till she goes.........
watch the temp and oil pres...

[Firewireal]

Oil and filter was changed out at the start of the season, along with all the other normal tuneup items and parts. I blew the rear main seal atleast, until i do a compression test and pull the oilpan to take a look inside. By the way; the oil pressure was stable at around 46 LBS pressure, and water temp was at 140 to 160 degrees running. I not one that just goes balls to the wall with my machinery. cost way to much to not do prentive maint. One thing that the Army taught me was do regular service maintance, before, during, and after each use.

[Tom@JBP]

Oil and filter was changed out at the start of the season, along with all the other normal tuneup items and parts. I blew the rear main seal atleast, until i do a compression test and pull the oilpan to take a look inside. By the way; the oil pressure was stable at around 46 LBS pressure, and water temp was at 140 to 160 degrees running. I not one that just goes balls to the wall with my machinery. cost way to much to not do prentive maint. One thing that the Army taught me was do regular service maintance, before, during, and after each use.

Don't want to be a downer but rear mains usually seep and leak but a massive rear main leak is likley a harbinger of bigger lower end issues Tom

BTW Thanks for your service to our country ! http://i147.photobucket.com/albums/r319/jetboatperformance/Misc/usaCa1.gif

[Firewireal]

well got her home and started pulling it apart pull the engine. found one of the lines to the left header, had a hole wore thru the the wire braid and the rubber hose IE no water to that header. that would explain the sudden rise in engine temp and possible drop in rpm's?? anyway fixed and started (added oil), oil presure is good, water temp is staying at 180 on the garden hose, no knocks, leaks that i can see, Rpms at ldle are good, and i can't see any leaks. Question; this is an old engine, guy I bought it from said that it was rebuilt 4 years ago (you know how that goes), could it be just burning the oil??? Just trying to find the easiest solution prior to pulling the engine.

BTW: when I said in an earlier post that there was alot of oil in the sump; what I meant was more than I have see in the past but not over a qt.

[RotorRider]

Hmm - Cut open oil filter and see if any metal/what kind.....Send some oil off for analysis and see whats going on.....not sure no water to headers would cause overtemp you saw, or vibration, etc. Check plugs for signs of any issues- once again you may have dodged a bullet, but as already pointed out, blown seal may be telltale of other serious issues....A rebuild/freshen up with new bearings, rings, seals, etc. could save/solve a lot of grief and money. Depending on what is found, it could run less than $1,500. now for peace of mind vs. the big bang.
Just thinking out loud. You are getting some good input from all the great guys here and their knowledge and experience. :thumbsup:
Gordon

[Firewireal]

I do appreciate all the input you guys have offered and I am really kinda getting of hualing the boat up only to let it sit and become a become an expensive swim deck. I think that I am going to pull the engine and see whats going on. Side question: should I sell off the goodies on this 455 and inturn finance a SBC and all it goodies? I was reading a couple other threads and they were talking about oiling problems on the top end. and that the jacuzzi pumps don't really like big power. some said that a smaller displacement engine would be the way to go. lots to ponder over the next couple of days. thanks for everything guys, "THIS SITE ROCKS"

[flat out all day]

naw bro iv seen big nasty big blocks with juccuzis and i have a wj in my boat and it runs great im about to get some big hp numbers here really soon so ill tell you if the pump has a problem and as far as the sbc if u wanna go slower go for it big block is the way to go wheather it be a bbf or abbc i got a ford and man wanna peall eyelids just lean into it more

[sschefer]

Well guys took the Ol' Jet to the lake this morning with alot of prayer and what I learned from all of you. The drive preformed better than it has in a long time. Good hole shot, good speed performance, had fun for the first three runs. Then Murphy's law stepped in and screwed things up. Fourth run started great; was running at around 3800 rpm, 46lbs oil, temp was about 140 to 160 at that speed and the water was really cold. Noticed a low freq vibe about 15-20 min into the run, rpms dropped to 3500 and picked back up again; then looked back and the engine was smoking from the valve cover breathers. Shut it down right away thinking I just blew the engine; temp soared to 250. So there we sat letting it cool off and wondering what happened?? After a half hour or so checked the oil to see if it had water in the oil and to my suprise there was no oil (and no water). Had some oil with me put three quarts in and gave her a try started right up and then died, several times and I gave up. Got a tow back to the dock, trailered and started messing with it and looking around. Lots of oil in the hull sump. Blown rear seal as far as I could tell. So looks like I get the fun task of pulling the engine and replacing at least that seal. Is there anything else that anyone can think of to check for as well because of the starting and dieing right away. I think I might have spun a bearing as well (low freq vibe)??? Any thoughts???

That low speed whirr/vibe could have been a main spinning and the start then die sounds like the cam may have gone flat. When you pull it apart, watch out for those lifter bases they'll be razor sharp.

[Hamjet]

Something might be stuck in the water feed to the engine. I think you mentioned it was a Olds engine.

Might have pumped all the oil to the tappet covers and blown it out of a breather.

At 3800 Rpm it should not do that IMO but anything is possible with an 455 Olds:D.

They don't like extended WOT runs unless the necessary oil mods were done.

HJ