did you replace the tach? 5700 at 71 is just too high, regardless of how many people are in the boat. either the tach is off, or the pump is severely cavitating at top speed.
just for comparison sake, my boat runs 104-106 at around 6175. if i back off to 5500, it's running 90, with a b impeller. my boat is heavy - over 700lb bare hull.
the point is, if you run into a wall with respect to speed increase because you have a lot of weight (drag) in the boat, the engine should not continue to rise in rpm - it is like a water dyno, and if power applied cannot overcome the drag, the engine will not accelerate any further. you either have a tach issue, or your pump is in need of some attention.
it is not possible to say you will automatically see performance gains just by bolting on a droop. it may work perfectly just bolting it on, but lowering the thrust centerline might create a porpoise condition or other handling issues, which will then be addressed by other things. i've seen too many instances where people were told "just bolt this on and your boat will run faster", then it doesn't on the first try, so the person gives up and takes the part back off. very unusual for it to happen that way. a droop will work on your boat, but it will have to be tested and adjustments made based on the testing.
You talking about testing for what degree of angle I would need to start with?
You talking about testing for what degree of angle I would need to start with?
too much "up" angle at a high enough speed will drive the boat out of the water. at the same time, too much down and you'll be plowing the nose. optimizing the angle -should- give you better performance because you're lowering the thrust centerline (i.e., making the boat ride higher on the water). porpoise can also start occurring when there was none before.
wot is Wide Open Throttle.
too much "up" angle at a high enough speed will drive the boat out of the water. at the same time, too much down and you'll be plowing the nose. optimizing the angle -should- give you better performance because you're lowering the thrust centerline (i.e., making the boat ride higher on the water). porpoise can also start occurring when there was none before.
wot is Wide Open Throttle.
Thanks. I guess I just have to do some playing around with it. But I really need to find amother tach, huh?
Bo
Thanks. I guess I just have to do some playing around with it. But I really need to find amother tach, huh?
Bo
yup..
yup..
Is there anything I can gain from taking the nozzle off the pump? Would there be any signs of pump damage from that end? could posssibly i see the stamping on the impellar? Or do I need to concentrate on the tach issue first?
Bo
no, there's nothing to see removing the nozzle, other than checking the condition or replace the o-ring, or the teflon gaskets around the pins.
you need a new tach. personally, i like auto-meter - their products are good, plus they have excellent tech support.
no, there's nothing to see removing the nozzle, other than checking the condition or replace the o-ring, or the teflon gaskets around the pins.
you need a new tach. personally, i like auto-meter - their products are good, plus they have excellent tech support.
Any certain model #? And how hard would it be to change from a manual distributor to MSD type. The engine now has points and I would like to get away from the manual distributor if possible. Any ideas?
Bo
Bo MSD (IMO) provides trouble free performance ! Very simple to swap ,you wont regret it Tom
Bo MSD (IMO) provides trouble free performance ! Very simple to swap ,you wont regret it Tom
I think I would need to use a conventional type distributor because of the tunnel ram. I would also need a AL 6 block, right?
no, there's nothing to see removing the nozzle, other than checking the condition or replace the o-ring, or the teflon gaskets around the pins.
you need a new tach. personally, i like auto-meter - their products are good, plus they have excellent tech support.
Where could I look at buying auto - meter?
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