what next ??

[jethroib]

Well first off this is one nice site to get information

what I have is a 1965 23' formula cuddy cabin that had twins in it originally
but were gone when I got the boat. So i reworked it to install a single mercruiser 888 stern drive in it and the motor is a 5.0l ford out of a 86 lincoln town car, used the marine parts and 2bbl carb. the prop is 19 deg pitch.

after all this work I take it out and it won't go on plane or faster than about 10 mph

either not enough hp or way to big a prop is my thoughts or will this combination ever work good enough to tube and ski the kids.

any suggestions are greatly appreciated
thanks in advance
eric

[stonebreaker]

Is the engine running OK? Seems like a V8 would have enough torque to get a boat that size up on plane, especially considering the cams they used back in the 80's to meet emissions.

Check for vacuum leaks.
Check to make sure all 8 cylinders are firing (look at the plugs). Do the plugs look like the engine is running too rich or lean?
Is the alternator timed correctly?
Are the rockers adjusted correctly?

Only after I'd eliminated the engine would I look at the prop.

[Preformer 40]

Whats your rpms at full throttle,bottom condition,drive ratio,prop currently?
a 15x15,or 15x17 would be a good starting place.

[jethroib]

the motor appears to be running smooth after replacing cap ,rotor ,condensor plugs ,and plug wires. timed it to 12 deg
I haven't checked the plugs after running it
I think the drive ration is 1.5
going to see if i can borrow a used 15 or 17 prop for the local boat store here in town.
do boats of this size and weight usually do good with this combination ?

[DaleG]

While the prop pitch would affect performance I suspect something else is wrong --- Performer 40 has some good questions -- but I wonder if the prop isn't slipping on the shaft. (assumin a Mercury outdrive) When you pull the prop -- and I am sure you will at some time -- look for evidence of the prop slipping against the thrust washer at the back of it -- if it is shiny and shows evidence of slippage that could be the problem. Good Luck
Dale G --- 2003 Four Winns 240 Horizon

[jethroib]

I forgot I had this open thread
It was a serious lack of hp. the engine in 1986 only made 130hp when new
so I put the 351 heads from the doner boat on it and a cam out of a 88 mustang and now it planes and pulls tubes etc. on to the next problems
thanks for the info.