1976 30' Sedan Crusier Prop issues !

[prowlersfish]

Rodman I was thinking he has a 400 , But if it is a 440 Marine engine it will be between 300 to 330 HP . THe info you gave was interresting but has no bearing on the output or rpm of the marine 440

[AbsterMcgee]

Actually the Chrysler is a 1976 400 B series motor, 300 hp stock, block casting # 3698-630

Prowler, I think I will run the 12 pitch for awhile, just to see what kinda fuel economy I get. Want to get it out for a full day and see what gives. I know @ 3600 rpm / 17 mph the secondary's are engaged and the fuel gauge is responding accordingly !!!! Cruising @ 2800-3000 rpm running on primary's I get around 14-15 mph, smooth running, and probably the most econimical. Gotta remember, mostly used for fishing 20-40 miles offshore of Daytona, 100 gal tank = 100 mile range, 100 gal EFree fuel = $405 @ Marina / $ 375 locally.
How much is Mahi Mahi @ the Market ?????

Thanks Guys
Abster

[captainmaniac]

Haven't read through all the posts so not 100% sure of your configuration, but if you only add 2-3 mph with a 600+RPM increase, you might have a trim issue... Do you have trim tabs and have you played with them a bit? Remember to trim it up or down just a bit (hit the button for about a half second) then wait for several seconds to see what the effect is -- the boat will take some time to respond (if nothing has happened by the time 30 seconds have gone by, its not gonna). Also keep an eye on it - especially trimming down. If you dig the bow too deep you could end up with a bad case of bow steer and possible stability problems (if you do, 'undo' what you just did asap!).

In my father's old 28' (single engine) and my twin engine F32, once you get up in to that RPM range and have it trimmed out properly you usually add about 1mph per 100 RPM increase, unless you have bottom fouling issues or strong headwinds that might hold you back.

All things considered, at 3600 RPM you should be in the 20-22mph range if you are getting 14-15 @ 2800-3000.

*UPDATE* just looked back through old posts and see that you DO have trim tabs... so if you haven't tried playing with them I suggest you do so. Different settings are required for different speeds, load conditions, and sea conditions.

[AbsterMcgee]

Hey All,

Captian M, went through all those previous issues, all is good as far as trim & hull.
Pulled the carb and having it re-built, should be ready today, Boat is running OK, doing the carb because I noticed slight pop or starvation when at WOT and 4 bbls kicked in. Rodman had sucess by changing / re-building his carb. Other than maybe pitching down one more degree as ProwlerFish advised, I think I will be satisified with the results of the changes made, End result is:

Originally Max 2200 rpm, max speed 10-11 mph (GPS), re-ptch prop from 14 to 12 Now 3400 rpm, max speed 15-16 mph, I think carb re-build will help this somewhat. Besides really do not want to be @ WOT unless emergency, very un-economical for sure!

Thanks for all the help, GREAT FORUM !!!!!!

Abster

[Rodman]

Hey All,

Captian M, went through all those previous issues, all is good as far as trim & hull.
Pulled the carb and having it re-built, should be ready today, Boat is running OK, doing the carb because I noticed slight pop or starvation when at WOT and 4 bbls kicked in. Rodman had sucess by changing / re-building his carb. Other than maybe pitching down one more degree as ProwlerFish advised, I think I will be satisified with the results of the changes made, End result is:

Originally Max 2200 rpm, max speed 10-11 mph (GPS), re-ptch prop from 14 to 12 Now 3400 rpm, max speed 15-16 mph, I think carb re-build will help this somewhat. Besides really do not want to be @ WOT unless emergency, very un-economical for sure!

Thanks for all the help, GREAT FORUM !!!!!!

Abster

when you get it done ill have to bring mine over we can go out for a trip