We have a 97 bayliner capri 20'05 with the 5.7 alpha 1. The prop is a 19p. The question that i have is we are running low on rpms at WOT. With just two people in the boat it will do right at 52-55 but only at 4200rpm. Loaded it is much under this and will only run 45ish. The tech told us it could be turned up to run a few more rpms so it runs up toward 4600 rpm. How can a guy adjust something to do this? Its a carburated motor so it shouldnt be hard. Or is there anything else we can do to tweak the top end a bit more?


On another note...test drove a 22'5 crownline with the 5.7 volvo engine pushing right at 300 hp and holy shizzle...that thing would make your stomach muscles sore trying to hold on while crackin the throttle. Unbelievable power out of the hole shot. It would snap a guys neck back when gunning it. Might be getting it next week if price comes down.

 

Generally a boats rpm's are directly related to the prop size and pitch. A "Big" prop with get you out of the hole quicker but turn at a lower rpm on top costing you top end speed. A smaller prop will be slower out of the hole but turn higher rpm and a faster top speed.

For me I run Four blade cleaver props on twin 600hp 502's.

 

trytokeepup...first off, did it run ok last season or has it always been running low RPM at WOT?? If it was fine last season, then you have something else wrong. Maybe some fouled plugs from winterization, dirty carb,bad thottle cable or a cable or carb in need of adjustment. If the engine is tuned and running as it should and you just need more R's out if it, check the prop and make sure you dont have a bent blade or a weak or spun hub. If you need more R's change the pitch of the prop. A rough, but pretty close calculation is, for every inch of pitch you INCREASE, you will DECREASE your rpm by 200. Just as for every inch of pitch you DECREASE, you will INCREASE your rpm by 200. Therefore in your case, I would swithc to a 17p prop. Putting you right at the top edge of the recommended RPM range. Then after you load up the boat with a few people and your beer, you should be running just fine. You never want to prop the boat so it will run fully loaded at the top rpm. You will kill the motor in no time. Good luck. One thing to be careful with the crownline is if it has a colored hull. They are notorious for fading real bad. Other than that, its a pretty good boat.
BREW

 

Thanks for the replys. So there isnt an adjustment on the motor itself to open it up a little? My uncle had thought a guy should be able to since its just a carburated motor. I know if we would go to a stainless steal prop it would help for speed a bit as the aluminum ones flex alot. We used to beable to smoke my uncles 19ft stingray with the 4.3 merc. This year he took us but we did have a lot more wieght in the boat as well. I just wish we would get that new crownline.

To be honest we had always heard SeaRays were the best boat out there so we test drove a new 24ft with the big motor. To me it seemed gutless and it took forever to plain the boat unlike the crowline. It also seemed to ride much more rough than the crownline inpite of being another 10 grand higher.

 

Like Brewdude said. If it ran fine last season and you had proper RPM at WOT and you havent drug the prop through a rock pile or anything then your prop did not change. So you just need a tune up or adjustment of linkage.

Edited to add:
Unless the prop hub is going out. Which I am not sure BREWDUDE could tell you but I dont think thats very expensive..
End of edit:

Sounds to me more like your trying to justify the new tub if not to yourself then maybe to your wife.
In that case then noooo! There is not a thing you could do to help it out! Sounds like the Prop is shot plus the engine amd lower unit are all going t ocrap fast. Better get another one soon.
BTW if your going to sale the "old hunk of junk" (wink wink) yourself when you get the new one let me know I may beable to help you find somebody.

 

with Searay, you are paying for a name anymore. They are good boats and all, but a lot of diehard Searay owners are making a switch. Theres to many other boats out there with more standard features for a much cheaper price. Also Searay seems to be getting uglier with its age (thats what everyone who has one tells me) I would deff. look into other brands such as like you said Crownline, also Rinker, Regal and Chaparral( I can never spell that right) They are just a few that are in the top 10 right now. Rinker makes a pretty sick 23 to 26 foot wake board boat. Its the RX series. Nice colors and some pretty cool graphics with a wake tower and all. Check 'em out.

BREW

 

BTW: BREWDUDE is your man when it comes to boats. He is the God of SternDrives. He won't steer you wrong.

 

Well since im 19 and no where near getting married hahaha lol....Its the parents' boat. Even though im usually the one that has to drive it and all that. I was very impressed with the crownline and the options and design of there boat compared to searay.

They offered us 11,200 on a trade in. Is this reasonable or how can u find someone? My grandma passed away during christmas time so we are still waiting on some money from the estate and the boat is one thing mom wants. Dad would rather buy a house on the lake or invest it into something better.

 

Pretty much like the KBB. We have BUC or NADA. It gives trade in values for boats. I know some guys that will quote right out of that book without ever looking at the boat. Its really the only way to do it and make the deal if your at a boat show. Take a look at the NADA book and you should be able to get a good idea of what its worth.

 

So short of changing the prop and all, what would be a way to gain higher rpms or increase speed? Weather its adding or tweaking the engine just whatever to maybe spruce her up.

 

Check for slack in the throttle cable, (Like BREWDUDE said it could need adjusting or WCS replacing) make sure that when the shifter is in WOT that the caburator is fully open too. Then the rest is basic mechanics just like a car. Tune up with new plugs, wires, rotor & cap, Carb adjusting, timing, etc., etc., etc.

 

As always, I agree with BREWDUDE. Maybe I can offer some more color commentary here too. The first thing you need to do is to make sure the engine is running as it should. Things to check for: Proper tune, decent gas in the tank, everthing in the throttle / shifter adjusted properly, gauges reading properly, etc. Yes, there are some adjustments on your carburator, but they're best left to a professional to mess with. If everything there is OK, you can play the prop game to get your RPMs to max out a WOT. (Wide Open Throttle) BREWDUDE was correct in his recommendation on decreasing pitch to increase RPMs.

There are a few other things that you need to consider when changing props though. For instance, PITCH is not the only variable. DIAMETER, RAKE, NUMBER of BLADES and MATERIAL also add their own twists. To pick one, 4 blade props tend to bite better than a similar pitch 3 blade, so you might loose RPM's even though you had the same pitch. Same goes for Stainless Steel as opposed to Aluminum props because aluminum actually deflects (de-pitches) under load. Hope that helps.

 

Oh yea, I'd also agree with BREDUDE on his recommendations for boats. I work for a dealer that sells Crownline and they are one heck of a boat. (Check the J.D. Power rankings and see!) By the way, just about any boat with the newer electronic fuel injection will really set you back in the seat on acceleration. A while back I took a 35' Fountain out with twin 496 HO's for an orientation ride with it's new owner. Talk about acceleration!

 

2stroked....can I ask where you work? tell me where and I'll tell you why I ask. Man, this will be weird..

BREW

 

Hey guys...so the sticker price on the crownline was like 54,000 or so...well the special price cuz it was a new boat series was like 42,000. They offered 11,200 for trade in. Any good ideas how to get the price down a few more thousand? What are some good tricks? They called today wanting to know. I would think they have room to come down yet.