Htp (the tech only version)

[TexasJet]

I just got back from Table Rock Lake in Arkansas. The 2nd 'ROOST FEST" was held there. As you may remember Duane did a lot of work on my pump last winter. Bottom line is, once I got the boat back to Texas, put the back seat, motor cover, swim step and all the other usual gear in it I had lost a few MPH from what Duane got in Witchita. He said he wanted to try a different impeller when we both got to the ROOST. We were supposed to meet Friday and do the swap, he was looking for me but I was on the lake having fun and kind of missed the time we were suposed to meet. I appoligized when I finally saw him late Friday night. I figured that was that and I would just keep my impeller. Now, Saturday night we just finished dinner at the banquet/party and we are standing around listening to the band and he comes up to me and says "lets swap impellers". Now keep in mind, he is on vacation with his family and we are at a rockin' party. To make a long story short, we leave the party, he swaps impellers and I pick up 2 MPH. I later found out he had the new impeller air freighted in so he would have it in time for TABLE ROCK. Cost to me-nadda-. Benefit to Duane, probably nadda cause some one will surely twist this around to put some kind of negative slant on it. This isn't cheerleading, this is just what happened. Omega Bubble Jet was there so he can call bullshit if I didn't tell it like it happened.

[TRG]

just to chime in here a bit: a few mo. ago, i had a question and wanted a non biased opinion on putting a pump together by using some different pump man. parts, duane did not know me as toddnjuzz from the boards but just as a guy from california. He spent at least a half an hr with me on the phone telling me the in's and out's about the differences in pumps and the cost of components,(schooling me!) duane is the sole reason why i went the route that i went during my pump re-build, dont get me wrong, jack knows his "shizzle" but i have not gotten to the piont where i am giong to use his services (need to save some more money) i dont think there is anything wrong with the way duane runns his buss. or jack for that matter, both of these guys are a "sure fire" bet that your questions will be answered to the "T" if they are asked.
Duane is doing a hell of a job and is one "HELL" of a "PROFESSIONAL"i might go one step further and say his customer service is way above par as well.
todd

[Rexone]

Miket as I posted before the board went down, from my experience with short jet drivelines, 2º is what I consider optimum angle. I feel that you're very likely to experience vibration with 7º. There's a good driveline angle link in the Gear Head tech thread section.

[miketsouth]

Originally posted by Rexone
Miket as I posted before the board went down, from my experience with short jet drivelines, 2º is what I consider optimum angle. I feel that you're very likely to experience vibration with 7º. There's a good driveline angle link in the Gear Head tech thread section.

As i responded before the board went down...thanks. What i did not say was "oh no, i hope not"
7deg is pushing it. I dont see how to get 2deg without moving the motor pretty far forward, and of course, a new driveshaft or have that one lengthened. Right now my oil pan is about 3/8" from the bottom.
I've done a lot of research. 4deg is max recommended by anyones advice. Even at that the angles must be balanced. Exceeding that recommended angle is supposed to mean accelerated wear, and i suppose increased vibration potential.
I did all i know how to insure that the angles are balanced.
The new spline coupling i lubed with mercruiser spline grease (making dam sure not to get any of that enigmatic stuff in or around the bearing). Dont chatter even out of the water now, and is tight tight tight. Dont know about what will happen in the water. Not until next weekend.
I am hoping that it was the loose spline coupling that was the problem. Not only does it tend to ride one side, it puts that part out of balance by being to one side.
I wasnt worried about the chatter. I wasnt real worried about the vibration, but i just dont want it. It means something aint right.
thanks again. Here are just SOME of the places i looked for information on drivelines. Nothing beats experience though. I am quite lacking
one place i looked (http://home.att.net/%7Ebenmlee/driveline/U-JOINT.htm)
a chart (http://www.pirate4x4.com/tech/billav...vs%20angle.jpg)
another one with a wear table (http://www.4crawler.com/4x4/CheapTri...line-101.shtml)
and an analysis program. Rather hard to understand, but by plugging different values into it, i kind of got the picture.analysis program (http://www2.dana.com/expert/wc.dll?cvsp~Dedsang~)

[Rexone]

Those look like some good resources Mike, I might add them to the Gear Heads section, I'll read through them later..
I'm sure you're already aware since you've replaced your spline portion that that wear and a little rattle at idle are not uncommon in jet boats. I'm sure its exasperated the more driveline angle present too. They do seem to wear though so don't be surprised if it rattles again at some point. I agree with you that the vibration isn't acceptable, hopefully you have it dialed in now.

[miketsouth]

Thanks again Rex. I have seen the rattle return just like you say in my bubbledeck. Close coupled 3point mount with very little angle. Ujoints still good, but the little rattle (out of the water only) returned quite quickly.
I got a chance to replace the shaft, coupler, bearing, seals, and lots of other stuff when i ignored a vibration and the coupler exploded in that boat. It was in that boat that i found that even on a closed coupled (cv) joint the angles must be balanced with the centerline of the joint. It is done with shims, or by motor locationl
I also chased needle bearings for the next two years.
mikeT

[Rexone]

Ok I just put this thread through the bs filter and it went from 121 posts down to 16 posts. 16 posts are all that had anything to do with the original tech topic MikeT posted on.
So that's why Hammer moved it. It had turned into a mainly drama queen, argumentitive circus. I support his decision.
I filtered this down just as an illustration of what happens to alot of the tech threads on ***boat. It does nothing for the forum as most people that would otherwise be interested are not interested in filtering through all the crap to find the tech (myself included).
I'm moving this "tech only" version back to Just Jets. I'm sure Hammer will return it to Bench Racers if you guys resume all the bullshit off topic crap. And rightly so.
You can still read and post on the full 121 post "drama" version of this thread in Bench Racers HERE (http://www.***boat.com/forums/showth...threadid=53111) as I split it into 2 threads before I edited this one.

[pops1]

Originally posted by miketsouth
mikeT Mike am I to assume the end item of this is a longer driveline to get within the 2-3 degree range or has the problem been identified as other. dave aggressor.

[miketsouth]

Originally posted by pops1
Mike am I to assume the end item of this is a longer driveline to get within the 2-3 degree range or has the problem been identified as other. dave aggressor.
We shall see. My research indicates that if set perfectly it will run pretty smooth, but wear on the parts will be more.
The tech links i posted above seem to be very good and informative if a bit long.
And, yes, the experineced say that getting the angles exactly right is "challening", as well as move the motor forward to get less an angle.
This vibration was not a killer, stop it right now vibration. I just know it can be done with no vibration.
mikeT

[miketsouth]

The vibration is much subdued, only slight vibration starting at 4500rpm and the rattle is gone, even out of the water it dont make no noise. I expect the rattle will return shortly.