Engine is not running right?...

[Chaparralboater]

I just bought a chaparral 18 footer with a 3.0 lx mercruiser engine..it's a 1991.. It came with a 15 pitch prop. The prop is chewed up pretty good and the boats bottom is painted and needs to be painted again. The boat won't rev over 4500 rpm or it starts to bog or maybe even miss. I put a 19 pitch on and it won't plane out with full tank and two people. I took it out by my self with the 19 pitch and she only revved to 3800 wot. I don't know boat engines or the first place to start and don't have money for the dealership to service it. By the way I have a small water leak from somewhere if that helps..cnan someone point me in the right direction of give hints if you know what's going on or have heard of these symptoms? Thanks a lot.

Derek-

 

[searay3]

Re: Engine is not running right?...

There are things that should be checked prior to purchase or sometimes a cheap boat can get expensive fast. your gonna need a manual. Give make, year, hp and serial number for proper manual. Get yourself a compression tester and do a compression test. That will tell you the general condition of the motor. A worn motor with low compression will not produce acceptable power. Pull the drive and inspect ujoints, bellows, gimble bearing and lube condition. Look for metal shavings or water in the gear lube. Gimble should spin with no rough spots. Ujoints should be free of rust and have no side to side play at each joint. If bellows looked cracked or old, replace them as it can sink your boat. A full tune up if compression numbers are acceptable is the next thing. Points or electronic: plugs, rotor, cap and points/condensor if you have them. Also check the flyweights to be rust free and move easily if points. Fuel system is next. Check fuel lines and tank for debris and function. Anti siphon should be free of debris and rust. Fuel filters and water separator if you have one. After all this, carb could still be an issue and need rebuilt or replaced. Old fuel needs to be removed as adding good fuel to bad gives you lots of bad fuel. Good luck and ask if you have any questions, a lot of talent here on Iboats...

 

[fat fanny]

Re: Engine is not running right?...

1st off I would'nt reve that thing to much past 4500 it's not rater for much more than that. Going bigger on the prop is gonna lower your rpms. Look into the prop forum for more info and input on that issue. 2nd If I were you I would go to the top of this forum and in the thread labeled adults only download the service manual for your rig I think it's #13? and read it cover to cover along with all the other free info there thanx to Don S and others. Also you need to track down that water leak especially if it's coming from the engine.