Full RPM's ???? or not.....

[notinbig]

Hey ya'll, hope everyone has had a wonderful summer so far with lots of time on the water. I know I have, best year yet. Any how I have an 88 larson 175 17.5' with a 4.3 OMC, my question is should I be getting better than 45-46 maybe 47 on a good day at 4200 RPM's full out. I full throttle then get the trim up a little(ok maybe alot) and thats it.?!is this good bad or ugly.....

 

[snapperbait]

Re: Full RPM's ???? or not.....

Notinbig, OMC specs the wide open throttle (WOT) RPM's for the 4.3 as follows...<br />w/2bbl carb: 4200-4600<br />w/4bbl carb: 4400-4800

 

[magster65]

Re: Full RPM's ???? or not.....

It sounds about right to me.

 

[notinbig]

Re: Full RPM's ???? or not.....

Thanks Guys. Is that about the speed also or should I play with the prop size?

 

[magster65]

Re: Full RPM's ???? or not.....

That choice is yours but remember a couple of things...<br />- an increase of 1" of pitch or diameter will cost you about 200 rpm @ w.o.t.<br />- dropping your rpm too low will cause the engine to be under too much load which in turn will give you poor fuel economy and sluggish performance.<br />- it doesn't hurt to do a little experimenting if you can borrow the different props.<br />- ideally a person would have 2. 1 for pulling and another for top speed.