Max RPMS for 1998 115 Carbed 60* looper

[evin268fs]

What is the max safe Rpms for this motor, I have read on reserched threads on hear and they like 5800 plus it seems but what is the upper end on a stock motor

 

[seahorse5]

Re: Max RPMS for 1998 115 Carbed 60* looper

5500 rpm

Some Intruder models went to 6000.

 

[evin268fs]

Re: Max RPMS for 1998 115 Carbed 60* looper

What about water pressure, never had a waterpressure guage before, I get low, almost no pressure at idle, 8-15 during midrange and 18-20 during WOT, is this normal, mortor shouldn't be too high it is only one hole from all the way down.

 

[Cricket Too]

Re: Max RPMS for 1998 115 Carbed 60* looper

You should have 8-10psi at idle and should be reading around 25-30 at WOT. When was the last time you put a water pump in it?

 

[evin268fs]

Re: Max RPMS for 1998 115 Carbed 60* looper

was purchased this winter from a dealer, was told complete checkup and had a clean bill of health. Runs really well

 

[Dhadley]

Re: Max RPMS for 1998 115 Carbed 60* looper

The rev limiter is at 6200. 5800 with an average load is fine.

 

[evin268fs]

Re: Max RPMS for 1998 115 Carbed 60* looper

was running over 6000 rpms, with a 17 pitch Viper, 43.5 GPS, had some cup added to the prop. Hopefully it will bring it down to 5800 or so.

Nathan

 

[Dhadley]

Re: Max RPMS for 1998 115 Carbed 60* looper

That should help. It depends on how and where they add cup but done correctly the prop should have less slip and also lift the hull better.

 

[evin268fs]

Dhadley: Max RPMS for 1998 115 Carbed 60* looper

Dhadley: Max RPMS for 1998 115 Carbed 60* looper

Dhadley, is it possible the limiter is set higher. By myself light with the 17 pitch prop worked by Mark Croxton in Indiana, he corrected the pitch to make it a true 17, said the pitch was alll over the place to begin with, and added tip cup add lift and to allow me to trim higher without blowing out. Light, by myself once trimmed out to 6400 rpms, 47.5,; still had a little trim left but got scared of the rpms I was turning. Runs 45-46 at 6000 rpms by myself, can back off the trottle and trim up to keep it at 6000. With another person, 210 me, another guy 225, 6000 rpms, 43, stopped trimming at 6000, didn't try to run higher. Is it safe to run over 6000, up to 6400-6500, or will my motor break, or is my tach off, and I shouldn't worry? Speeds are gps, and Mark told me to use 17 in the prop, slip calculator, so I think I am indeed turning these types of rpms.

 

[Dhadley]

Re: Dhadley: Max RPMS for 1998 115 Carbed 60* looper

Re: Dhadley: Max RPMS for 1998 115 Carbed 60* looper

If the tach is an OMC or Bombardier tach and is set on position 6, it should be very close. Just make sure it's not set on position 4. Check that and we'll go from there.

 

[evin268fs]

Re: Max RPMS for 1998 115 Carbed 60* looper

DHadley,

Checked and tach is correct, is it safe to turn it this high, really love the way it performs, the 17 really jumps out of the hole, 47 is quick enough if it is safe otherwise I will be looking for another prop. It is the prop that came with the boat.

 

[Dhadley]

Re: Max RPMS for 1998 115 Carbed 60* looper

It could be at 6700. You're at 10% slip or less so that's really good. If it were mine I'd be tempted to try a 19. Or even a 20 Raker or Turbo Lightning Jr. Just going to a 19 would put you right at 50 if it only turned 6000 with the same slip.

What kind of boat is it?

 

[evin268fs]

Re: Max RPMS for 1998 115 Carbed 60* looper

1998 Stratos 268 Fish and Ski, i believe 16'8" Motor one hole from the bottom, before prop work rooster tail 6-8 feet over top of motor cowl, after prop worked rooster tail level to 1 foot above top of cowl, 18-20 water pressure at WOT a lot of the boat out of the water, full tank three batteries, light fishing load, just me 210lbs.

Just found a 19 Viper, I will have it worked as well, like the big diameter, trial a 13 x 19 and it was terrible would not lift the boat.

 

[evin268fs]

Re: Max RPMS for 1998 115 Carbed 60* looper

I think this time I will have him leave the progressive pitch, not repitch to a true 19, add the cupping for bow lift and holeshot, and add exhust holes. I think I have read the progressive pitch is better for holeshot, the true pitch bett for speed. Hopefully adding the exhust holes and leaving the progressive pitch will keep the holeshot about the same as the 17 as I like to slalom and would like to not be changing props all the time.

Does this sound like a good plan?

 

[evin268fs]

Re: Max RPMS for 1998 115 Carbed 60* looper

Found a 19P Viper and bought on ebay last week, sending it to be worked, will have it repitched, talked to Mark and he stated the pitch is reversed on the Vipers, also adding same cupping as I did with the 17 and having vent holes drilled should get it this week and try this weekend