jetaway, duane?

[quiet riot]

Duane or somebody using a jetaway,
By removing the h-bar/1 u-joint I gain 2 3/4" and the bearing cap is 1 3/16" thick. You said the housing is 4 1/8" long, right? So it sounds like that will pretty much take up the diff in space the jetaway uses. And it'll fit a legend j120-g, right?
I heard somebody mention that you can use the jetaway to disconect the pump and run the motor on the trailer. Is this correct and how is it actuated? I have a completely enclosed motor and was wondering if I could actuate it from the outside with a cable or something.
Also, the unit has a oil reservoir that sits atop it, right? Just wondering how big it is. And is this pretty much a maint free thing once installed? Doesn't have to be reset like a pop-off?
Anyone have some feedback as to the diff it made when letting off at speeds on something that was a little squirrelly before the jetaway install. My boat gets a little squirelly over 80 (short, deep, deep vee, light jet) and when my msd box died once it just about pitched me.
Thanks,
jd

[Duane HTP]

jd,
Just yesterday I installed a Jetaway in a customers boat and took careful measurements while making the change over.
I think this is the measurement that is most useful to you.
When the Jetaway was installed on the pump, the front end of the splined pump shaft ended up 4.350" further forward than the original one was.
So, you would have to move your motor or pump that much to use your present driveline. You can gain 2.75" by removing the H-Bar, another .500" by shortening the splined yoke, and if it's a Spicer drive line, you can gain another .250" by machining down the flywheel adapter. But, that's only a total of 3.500". You still need to be .750" shorter. You can gain .500" more by changing yokes to a Spicer Part # 2-4-6011. Another thing that you can check, is the depth at which your present yoke goes on to the splined shaft, it may have the other .250" of play available there. Just be sure that when you're done that you have about 3/16" clearance for the yoke to move on the shaft before it bottoms out, due to the flexing of the boat and engine mounts.
Yes, you can run your motor on the trailer without damaging your pump with the Jetaway. It's actuated by moving the shifting ring back and forward by use of the two knolbs seen in the picture to the left. I suppose you could rig up some sort of cable, but strongly recommend not to. I have built them with an air shifter before and ran it on my race boat. But one screw up and you will be in deep $$$. I twisted a Lenco Drive Shaft so bad that the yokes would not slide and we had to cut it out with a torch.
The unit contains the oil inside of it. Some people put a breather canister on top of them if they are running a high HP race boat to take care of the oil expansion. (not a bad idea). Just like an engine, the oil should be checked periodically. NO, they don't have to be reset like a Pop-Off. They work automatically.
The unit helps eliminate a lot of the intake pressure spikes upon engine failure. I'll let the actual users take over here and give their experinces.

[promod]

never seen a rachet on a controled cable only thing i could figure is doing some major fab to get it to hook to a cable but if it isn't to had to get to i would just leave it alone for the stock slide sleeve anyway it takes up around 4 1/8 area best thing i used to warm motor without hurting pump epsically if you have alot in the pump my 02. anything over 80 would highly recommend any way of saftey, my boat shut cable lock came loose an accidently shut fuel off around 100 and the pump kept turning, the boat layed down and went straight
later
promod
baj#817 :wink: :p :D

[quiet riot]

Thanks for the responses, I'm gonna go do some measuring and thinking.
jd
Oh yeah, I understand the pressure spike thing for engine failure, but would it also help with the surge of dropping a few hundred horses when I let off of full throttle and the n2o shuts off? And this won't have any adverse effects on the unit having it do this fairly often, right? Would it even use the jetaway in this instance or only if motor completely shuts down? When I let off it loses about a thousand rpm and I usually have to feather the throttle a little to keep it stable.

[Duane HTP]

If you drop rpm very much, very quickly it will always work. No, it does not hurt to use it every time you shut down, but doubt that you will.

[screamdreambrad]

Originally posted by quiet riot
Thanks for the responses, I'm gonna go do some measuring and thinking.
jd
Oh yeah, I understand the pressure spike thing for engine failure, but would it also help with the surge of dropping a few hundred horses when I let off of full throttle and the n2o shuts off? And this won't have any adverse effects on the unit having it do this fairly often, right? Would it even use the jetaway in this instance or only if motor completely shuts down? When I let off it loses about a thousand rpm and I usually have to feather the throttle a little to keep it stable. it's not going to straighten your boat out when it settles back in from wide open, thats drag not overloading the pump, i'm sure. but it will work, ( when it severly overloads, as in motor shuting off)just not like a flat bottom with a whirlaway, how they blast down the strip then just side step the throttle. just can't do that in a jet boat. brad by the way nice spline rotation!

[cruser]

QR
If you want to see an installed JetAway, I have access to one and live just down TV highway a couple of miles. I'm not working until Monday but you could email me at home if you want to go see one.
I also read you are going to the boat show this weekend. Maybe I'll see you there. Ray always has a booth and has quite a bit of Jet knowledge. The drag boat might be there also.
cruzer

[quiet riot]

Cruser, thanks for the offer. I plan on talking to ray. Not sure which day I'll go, I don't go back to work till Wed next week after getting off sat morn. Waiting for pricing from duane on a bunch of stuff in the meanwhile too.
jd

[Duane HTP]

Have you checked your pm?

[quiet riot]

Duane, got it. Check your pm.