prop help or maybe something else please

bolo789

Petty Officer 1st Class
Joined
Aug 26, 2002
Messages
376
hi guys, i need a little help again <br /><br /><br />1989 0r 1990 searay 220 DA aft cabin 22 foot merc 5.7L 260 HORSE <br /><br />with a 19 PITCH PROP I AM ONLY GETTING 3000 rpm wot throttle the engine runs fine no miss, the carb seems ok just not passing 3000 rpm.<br /><br /><br />i disconnect the link from the carb to make sure the rev on the carb is going all the way and that seems fine.<br /><br />so what could be the prob don , the plugs i have in right now is the same ones i use to trouble shoot during the winter, my carb was flooding so much at that time you think those plugs are no good???<br /><br />thanks much i will be waiting for all the infos<br /><br /> one last thind i have a 17 ss prop it is a little diffrent from the one i have on right now, it does not use the big washer at the end of the drive shaft with the little ends that you crimp down when the nut is tight, it came of the shaft that use the pin at the end. i put that big spacer over the shaft put the prop on it fit perfect , but, will the nut at the end hold it safe by itself??
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: prop help or maybe something else please

i am hopeing you have done the basics and the timeing is correct and advanceing ect<br /><br />it is a heavy boat that you have pieced together so you have no track record on what it should do with what prop<br /><br />the only thing that will rule the prop out is trying a GOOD 17 in and see what it does<br /><br /><br />the 17 in you talk about does not sound right<br /><br />tommays
 

f_inscreenname

Commander
Joined
Aug 23, 2001
Messages
2,591
Re: prop help or maybe something else please

If he is running a 19 and only getting 3000rpm's, a 17 is only going to get him 3200 rpm's. Way to low rpm's. Change your plugs and do a complete tune up and then see what you have. You also said you had carb problems before. I hate to say this but you still may. To much gas, not enough. Its a fine line. A motor will rev to the moon with vary little gas when in neutral but when the motor is under load it needs every last drop.
 

bolo789

Petty Officer 1st Class
Joined
Aug 26, 2002
Messages
376
Re: prop help or maybe something else please

i see , thanks guys i will do that tune up and retest <br /><br />thanks much
 

Mahoney

Chief Petty Officer
Joined
Aug 2, 2004
Messages
537
Re: prop help or maybe something else please

After you check things out after the tune up, pull all the plugs and check them after a good run on the water. Make sure they all look nice and tan like they were firing. Everything can sound fine with a V8 and still be only on 7 cylinders.
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: prop help or maybe something else please

i have a 17,19 and a 21 inch prop maybe because its a 3.0 on a heavy boat but theres a lot more than 200 rpm differnce between the 17 and the 19<br /><br /><br />tommays
 

f_inscreenname

Commander
Joined
Aug 23, 2001
Messages
2,591
Re: prop help or maybe something else please

I'm sorry tommays, you are right. I was supposed to say for every one pitch up or one down is 200 rpm's so that would be a 400rpm increase.
 
Top