1993 Sunbird

[SJPJWM]

I have just purchased a 1993 Sunbird, 4.3 6cyl, OMC, Cobra. Two questions, first, any ideas on how to obtain a owners manual? Second, the original prop is on the boat and is a 14 1/2 x 19. Is this the recommended prop for best all around performance? Thanks.

 

[GregCC167Concept]

Re: 1993 Sunbird

Have you checked ebay? I've found stranger things there.<br /><br />As far as the prop, if it's the original that the boat is equipped with, then it's probably what they recommend as the best all around. Is the hole shot and/or time to plane pretty good? If so, what are your RPM's at full throttle? A manual would tell you what rpm range you should be in but someone on here might know it as well. If you are turning too many rpm's you might need to move up in prop pitch. Too little, move down. Rule of thumb about 200 rpm's for each change in pitch.

 

[SJPJWM]

Re: 1993 Sunbird

Greg, thanks for the response. With two people in the boat, we reached 42mph at about 4200 RPM. Seems like low RPM to me but I have been used to 150HP outboard and this is 4.3 I/0. Comments?

 

[akriverrat]

Re: 1993 Sunbird

rpms 4300-4800. overproped a couple of inches or boat has gotten heavy or engine needs tuneup.

 

[SJPJWM]

Re: 1993 Sunbird

What is the cost of the tune up you recommend and what work is normally done? The former owner of this boat claimed it had only 25 hours use in 10 years. Should I ask him about ocean front property in Arizona? Jim Merkle