Hi All
I have a 1990 Cheetah 210 ES bowrider, Alpha1 5.0LX, 305 230HP, WOT 4200-4600 - as stated on the carb cover.
When I bought the boat it had an aluminum 3-blade 15x15 prop- could barely get out of the hole, especially with passengers.
I pulled the prop and installad an Alpha4 18P and the bost responded very nicely, up on plane quick, excellent mid-range, but the tach crowds 5K around 40-41MPH.
I pulled the Aplha4 and installed a Power Tech ELE4 19P with pretty much the same results, no noticable difference in RPM's.
I pulled the ELE4 and installed a Mercury Black Max 3-blade aluminum 21P and it behaves, again, just like the others near redline, but lazy out of the hole...not so bad, but a little lazy compared to the 4-blade. The 4-blades stay on plane when you throttle back, whereas the 3-blade the stern will drop right in the water.
So at this point I need to get back approx. 400-500 RPM's and I'm not sure where to go. The dealer states I can exchange the ELE4 19P for an ELE4 21P and I "should" get back 400RPM, but I am worried that will be trivial progress in light of what has transpired thus far. I am fairly certain my tach is calibrated properly but will be verifiying this weekend. The Quicksilver tach I think it is set at 6P and there is an 8C adjacent setting I have not tried. All I can say is the tach "feels" right.
Do I need to pitch up to 23P or even 24P at this point or go back to the drawing board with this project?
I am pretty much at sea level in Michigan, the Cheetah is probably above average in weight for a 21-foot boat and gets sluggish when you start adding adult passengers. The gear ratio stamped on my drive is 1.50.
Any assistance is appreciated.
I have a 1990 Cheetah 210 ES bowrider, Alpha1 5.0LX, 305 230HP, WOT 4200-4600 - as stated on the carb cover.
When I bought the boat it had an aluminum 3-blade 15x15 prop- could barely get out of the hole, especially with passengers.
I pulled the prop and installad an Alpha4 18P and the bost responded very nicely, up on plane quick, excellent mid-range, but the tach crowds 5K around 40-41MPH.
I pulled the Aplha4 and installed a Power Tech ELE4 19P with pretty much the same results, no noticable difference in RPM's.
I pulled the ELE4 and installed a Mercury Black Max 3-blade aluminum 21P and it behaves, again, just like the others near redline, but lazy out of the hole...not so bad, but a little lazy compared to the 4-blade. The 4-blades stay on plane when you throttle back, whereas the 3-blade the stern will drop right in the water.
So at this point I need to get back approx. 400-500 RPM's and I'm not sure where to go. The dealer states I can exchange the ELE4 19P for an ELE4 21P and I "should" get back 400RPM, but I am worried that will be trivial progress in light of what has transpired thus far. I am fairly certain my tach is calibrated properly but will be verifiying this weekend. The Quicksilver tach I think it is set at 6P and there is an 8C adjacent setting I have not tried. All I can say is the tach "feels" right.
Do I need to pitch up to 23P or even 24P at this point or go back to the drawing board with this project?
I am pretty much at sea level in Michigan, the Cheetah is probably above average in weight for a 21-foot boat and gets sluggish when you start adding adult passengers. The gear ratio stamped on my drive is 1.50.
Any assistance is appreciated.