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-   -   Silent Thunder repair (https://www.offshoreonly.com/forums/formula/372267-silent-thunder-repair.html)

Tony S 06-30-2021 07:36 AM

Silent Thunder repair
 
I’m looking for any suggestions/advice on repairing our silent thunder platform on an 87 242ls. The rub rail no longer stays attached. I’m thinking of removing the platform at the end of this season.

Also, any information or thoughts on switching to. four blade stainless prop. Currently using a three blade 14x21. I’ve read that you normally drop down one pitch when switching to a four blade prop. The 242ls has the 454 with after market intake an d carb. I think the 19 would give me a little better low end performance out of the hole. I’d rather sacrifice a couple of mph top end. I know the 242ls is not a speed demon.

Many thanks for reading,
Tony S



ph1971 06-30-2021 05:05 PM

I think a 20 p Revolution would be perfect for your app. I will warn you that this is a somewhat pricey wheel, but the control and manners are super. Does your platform have rail rivets? Mine did. I drilled the rivets out and reattached the rub rail with #10 stainless oval head screws. Be prepared to find more work if you take things further apart. As far as your hull not being a speed demon, well that just depends on how you motivate it. There have been a few 242’s on this board that I would absolutely call speed demons. It all depends on how fast you want to spend. Good luck and great boat!

distantthunder 06-30-2021 10:18 PM

I have good luck with Bravo four blades on my Formulas. Ran a 24P on my 223LS and a set of 26P on my 292SR1

The ST platform sounds rotted, time to ditch it. May gain a MPH or two.

Tony S 07-01-2021 06:45 AM

Thanks for your reply and suggestions. May try a removal and rebuild of the ST at the end of this years boating season.

Tony S

Tony S 07-01-2021 06:59 AM

Thanks for the quick reply and suggestions and recommendations on propellers. My son in law and I may tackle a rebuild of the ST platform at the end of the season here in the northeast. Local marina will to a repair to get me through the season. Do you have any info on Solas, Turning Point or Bravo props. I know revolution props are pricey. What diameter should I look for with the 20 pitch..The drive is an Alpha 1. I’m new to this I/O world being a two stroke guy for many years. Always wanted the older Formulas the 242 ls. It is a great boat.

Thanks again for your help,
Tony S

TomZ 07-01-2021 05:13 PM

Junk the pos platform. They can and do cause transom rot. I love you Formula but that was an absolute crap design. I know there are purists out there that say removing the platform takes away from the look. I say good luck with transom rebuilds. A tubular platform looks good on them especially if color coordinated.

Ditch the platform, your 242 will thank you.

I have nothing to add on propellers other than the say a 26P Bravo is not enough prop for a supercharged 242. :drink:

ph1971 07-01-2021 07:52 PM

As if on cue, the 242 speed demon himself shows up. LOL

TomZ 07-02-2021 07:46 AM

Certified nut is more like it. :cool-smiley-027:

ph1971 07-04-2021 10:46 AM

Hey TonyS, there is a rev 19 that just came up in the swap shop. I would jump on that one if I were you.

NHGuy 07-09-2021 09:16 AM

No one has asked what RPM you are getting from the 21. If it's getting where it should a 20 or 19 will be nice with the extra blade. But if it's held back bay the high 21" pitch you might need to just go all 19. I have a 19 Mirage Plus and it revs out well, I also have a 21 and it still gets 4550 or so.
An Alpha1 behind a 454 is a potential weak link. I have one in back of my 383. My engine probably doesn't make near the torque yours does and a 223 is lighter. To keep mine happy I put Amsoil Severe Gear in it and I put on a drive shower too. Cheap insurance.
In the meantime don't holeshot it too hard, just slide it onto plane.

Also, I believe TomZ has a bravo drive, he may have a taller gear set than we do. But if he's spinning a 26 with a 1.5 gear, that's cooking with gas!


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