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brucehearron

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"Hey Guys, it's been awhil

"Hey Guys, it's been awhile. Still reading challenging senarios though. Have '84 twin 454 Crusader 350's. 20K #Silverton. What is the WOT RPM's. Mine full throttle is about 35K RPM with no throttle left. Reading your discussions on similar models should be be in the 45K range. Is this all I get or is the throttle cables set to low? I know your thinking just deal with it because of the fuel consumption. Just think these engines should be able to turn more RPM's.
Thanks
Bruce"
 
"Bruce,
It could be you are s

"Bruce,
It could be you are swinging to large of wheels. I don't remember the exact formula but basicly for every added inch you lose 1000rpm and the same goes for the pitch. Good luck!"
 
""35K" rpms! "45K

""35K" rpms! "45K" rpms! What are you running, gas turbines?

Just being serious......That's a mite low for such a heavy boat, but you need to do some research FIRST before messing with props or etc.

Try this: Warm the motors thoroughly and run the boat at a comfortable cruising speed. (Let's say 20 MPH for discussion only.) Open one throttle all the way and record the rpms achieved, then return it to the setting that makes 20 MPH. Next, open the other throttle wide open and record what it does. If the two are similar with in 50 rpms, then your low rpm problem is not engine related.

What you're doing here is determining if one engine is dragging down the other. No way can Mr. Port reach, say, 4,500 rpms, if Mr. Starboard isn't pulling its share of the load.

Jeff"
 
Did the engines ever turn 4200

Did the engines ever turn 4200-4400rpm since you owned it? If so it isn't a prop size or pitch issue. Some people used those big boats as cottages and put on bigger wheels/ higher pitch to try to help fuel economy at lower speeds. If you could never achieve 4200 rpm that could be the issue.
 
"Hey Jeff...

That sound lik

"Hey Jeff...

That sound like a nice tool to use. Just for arguments sake, I wonder how our boat would come out in that test with the new monster props... You are saying that 1 engine can't achieve it WOT if the other won't help it along?

By the way...Is there a different prop puller for 4 blade props over 3's ?"
 
"After a engine blew on mine,

"After a engine blew on mine, the boat sat a long time during the repair. One of the props (just one for soe reason) collected a huge layer of barnacles. The prop barely pushed the boat at low speeds, and it absolutely refused to plane off. After a good scraping, all was well.

Jeff"
 
"OK FastJeff, I got it, had to

"OK FastJeff, I got it, had to make a stupid look for a few seconds but alls well. It's a wonder what a decimal point can do. Anyway, I never would have concluded that might be the reason. I think I do have an oversized props. 21" comes to memory when I read the specs in November when I was buying. I'm the third owner and the owners manual seems to have good records. I don't think the first owner used it in that way. The previous owner lived on it for 3 years and didn't change the props. Also, I had a bottom job done in January so growth is probally not an issue yet (Fingers Crossed). Next time out i'll try your test. Thanks
Bruce"
 
"Al,
I believe there is a

"Al,
I believe there is a different puller for 4-blade props since my co-worker gave me a puller for my 3-blades and said it was of no use to him since he had a 4-blade prop. But, I'm not postitve on this."
 
"My prop got covered with barn

"My prop got covered with barnacles in far less time than that. If you're a good swimmer, you could dive down there and take a look.

Jeff"
 
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