HST Help

[Vegas86]

Hey guys, I have an issue with my HST I believe may be somewhere in my setup I cannot figure out. I need some help before something bad happens. This has happened a few times lately at about 88 to 90 MPH the boat will all of a sudden jerk left not hard left but enough it scared the sh$t out of me yesterday . 89 HST, 97 225 Promax, 30 Pro ET prop, CLE lower, 10 inch hydraulic jack plate, hydraulic steering, prop shaft running even with the pad or 1/2 to 1 inch above . What is going on ? Any help would be greatly appreciated Thanks

[cyhuff]

You're experiencing prop blow out... very scary at those speeds. Plenty of guys on here can point you in the right direction to adjust your setup. Be patient.

[LakeFever]

Paddle wheeling? My Valero did this to me a few times and it freaked the living hell out of me. My wife riding shotgun didnt even notice though which is weird to me. I blew out that prop a few times too and it just sank back into the water a few inches but while tracking true, no turn. The paddle wheel happened with too high engine height turning the boat and only at full jam. I ditched that prop and never had it again. My one and only experience with it, not sure if any help for ya but lowering the prop or changing to a different prop will likely change that specific behavior your dealing with

[Vegas86]

So that is what blow out feels like ? Prop maybe has too much lift in the ass end ? Drop the jackplate down or less positive trim ? Any suggestions on a prop ? I have a Hoss Triton 28 but it will not quite get to the same speed it is on the limiter too. I still have some throttle left in the Pro ET I was turning about 6400 to 6500 when this has happened . Thanks guys all suggestions greatly appreciated I want to fix this problem & be safe going faster ,one note I have seen 94 on GPS with this prop so it is likely something I am doing ?

[LakeFever]

Mine had two distinct behaviors; Blow out where it would drop straight down into the water and quickly grab and lift back up again. From drop to return was about 2 seconds. The paddle wheeling was wayyyy freakier and at first I thought the water was playing tricks with my eyes because I could swear the boat was moving sideways. After a few more attempts I managed to get this to happen quite quickly. I was tracking sideways noticeably while still scooting pretty good. I have since learned I probably had the worst set up possible for this because that motor would only get up on the pad pretty much wide open being a 135 it didnt have tons of jam and that zone between wet and air is sloppy which is where this boat lived. Sloppy pad two hands on hang on tight! My new 200 V-king pops up on pad so fast you can one hand it and cruise with ease. It likes choppers

As for your prop? I have no experience at all with those hulls so I dont know what works best. Maybe try a cleaver?

[David - WI]

I also have an HST with CLE and haven't had it blow-out yet... but I do have a "blow out ring" to install when I get this newer motor set up.
See: https://www.screamandfly.com/showthr...89#post1237689

[Vegas86]

What prop you running & speeds ? Thanks for the thread good stuff makes sense see if I can find one & try it out

[David - WI]

Different motor now... it was a mostly stock 2.4L 200 with a chopper (26 or 28) at 88 - 89 mph.

[bigboy]

I had the same happen with stock 200 lower at 86mph.

Than got a CLE but I added a blow out ring made out of epoxy from the start.

Did 96 max. Havent experienced blowout with the cle.

[Vegas86]

Hey guys , update , I got my blow out ring Sat. & installed it ,I have one issue, it fit but the outside diameter is about 1/16 of an inch larger than the diameter of the gear housing all the way around? Is this correct or do I need to machine it to the same diameter as the housing ? It is raining here so I haven't had a chance to test & see how it will do . Thanks

[LakeFever]

Thats correct. Heres a pic of a stock V6 200 lower

[Vegas86]

Thanks my man, I feel much better now, that is about what it looks like . I will test one day this week see what happens & update . Again Thanks very much

[bigboy]

I ran my a5 30p chopper this weekend. I think i experienced the same. Stern was rapidly sliding from left to right. I ran the same prop a yeae ago and didnt experience this. Maybe too high? My fuel tank was almost empty too.

Out of curiosity: what props have you run and what numbers?

Regards

[Vegas86]

I was thinking I might have run my jack plate too high also to cause this issue, I have it marked even up to 1 inch above the pad in 1/4 inch increments but can only see the marks after I slow down ( dont want to turn around that fast ) my fuel tank was also low I know these boats are very weight sensitive so that may also be part of the issue . I have a 30 Pro ET on it now that is when this started happening. I also have a 28 Pro ET no issues & a Hoss Triton 28 that has been worked all Tim Bostic says he could do to it no issues both these props 88 MPH the 30 I have seen 94 MPH but the blowout has happened between 88 - 90 MPH with that one. I plan on trying again Sat. with the ring installed see what happens ? I will update you guys on progress . I may sell the Hoss & 30 Pro ET & try a 30 - 32 Lightning ET or another Hoss 30 - 32 my goal is 100 +. Tim has told me a 30 Triton worked should put me there but this issue has me a little uptight I want to figure this out & know what is causing it so I can avoid it .

[LakeFever]

Again a totally different hull but mine paddle wheeled when the motor was lifted out too high for that prop. It didnt have the right bite I guess. Chopper cured it for me the one I have makes the boat feel like its riding on the prop and the hull is only along for the ride. Its super grippy but its a chore to get it out of the hole without putting the nose into the sky for 10 seconds. Crazy really I thought it was going to sink the first time I ran this thing. Dang props, always something you want to change up and then you give up something else being taken for granted.