Need help with my 220gpu

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Masker220
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Need help with my 220gpu

Post by Masker220 » Sat Jun 02, 2018 11:53 am

I have a 12' river master with a 220 gpu and it won't run dry at all. I have a 72" water walker signature series prop currently pitched 10 degrees. Had it pitched to 20 but the motor did not like that. Hull is set up for jacks but not sure if that would help. Any and all advice is welcome.
12ft river master, 220gpu, 72" waterwalker signature series

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kwanjangnihm
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Re: Need help with my 220gpu

Post by kwanjangnihm » Sat Jun 02, 2018 12:10 pm

What was your rpm at the 10 & 20 degree pitch?
Sigs like 2800. :thumbleft:
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Masker220
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Re: Need help with my 220gpu

Post by Masker220 » Sat Jun 02, 2018 12:44 pm

I'm not sure tach cable broke on me. Waiting for a new one.
12ft river master, 220gpu, 72" waterwalker signature series

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Deano
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Re: Need help with my 220gpu

Post by Deano » Sat Jun 02, 2018 1:45 pm

Given that you don't know what it's really turning, I'd likely wait on that tach.
With a healthy 220 and that prop, it certainly should be able to run dry barring something out of the ordinary.
As was pointed out 2800 is the number to start with those blades.

As far as the jacks go, if it runs OK in the water, it's likely best to leave them be for the time being.
If your prop is not perpendicular to the stringers is should be real close (or crank parallel to the stringers, same difference), possibly just a hair higher at the prop end.

Those last two are hull fine tuning issues that really need dealt with AFTER you have the engine right and the prop pitched sufficiently to hold a given RPM, because ultimately that is how will cage changes. You don't want to over spin the prop, nor do you want to leave any power on the table. It's a little beyond difficult to pull that off without a tach.

How does it currently run in the water? If it is running OK but just won't run dry, you are likely down on power and/or lacking RPMs.
Here again, you come back to needing a tach to make and/or confirm that possibility/likely-hood.
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Masker220
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Re: Need help with my 220gpu

Post by Masker220 » Sat Jun 02, 2018 2:17 pm

With the prop pitched at 10 degrees it rides fine in the water. I also heard it might be a timing issue but it sounds like it's running good to me. Guess I'll just get that tach figured out first. Thanks guys.
12ft river master, 220gpu, 72" waterwalker signature series

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Andrew McD
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Re: Need help with my 220gpu

Post by Andrew McD » Sat Jun 02, 2018 4:10 pm

10 degrees sounds right for a healthy gpu at 2800 RPMs. Doubt it’s motor or prop. Will the boat hop on the water and if so at what kinda speed? Where’s the spray coming out and any wear spots on bottom? Weight has to be a bit further back on river masters sometimes or else they plow and wear prematurely right at the bow roll.
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Masker220
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Re: Need help with my 220gpu

Post by Masker220 » Thu Jun 07, 2018 4:01 pm

UPDATE: bought a small digital rpm gauge and I'm only turning 1350 rpm with prop pitched at 10 degrees. So I don't know what to do now.
12ft river master, 220gpu, 72" waterwalker signature series

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kwanjangnihm
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Re: Need help with my 220gpu

Post by kwanjangnihm » Thu Jun 07, 2018 4:38 pm

you sure its not 1350 x 2 = 2700? 1350 wont get you up on plane..... :scratch:
" I don't care who you are back in the world, you give away our position one more time, I'll bleed ya, real quiet. Leave ya here. Got that? "

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Deano
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Re: Need help with my 220gpu

Post by Deano » Fri Jun 08, 2018 9:11 am

kwanjangnihm wrote:you sure its not 1350 x 2 = 2700? 1350 wont get you up on plane..... :scratch:
Agree with this 100%. No question that makes the most sense.
Is it a Tiny Tach?
Does it use an inductive pickup from a plug wire?
Does it have a switch to select # of cylinders?

Maybe it's bad out of the box. Can you exchange it?
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but it is not the path to knowledge; it has no place in the endeavor of science."
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goldhunter_2
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Re: Need help with my 220gpu

Post by goldhunter_2 » Fri Jun 08, 2018 6:08 pm

wellllll 1350 "can" get him on plane in water, and ride but never push ground if that numbers right (that's defiantly not a rpm most are running) wait and get a good cable aircraft tach IMHO then figure out what you need to be adjusting or find someone local that a bit more knowledgeable then you to help

you didn't mention what the boat of our boat is like or what on it . (poly, slick bottom , bare glass)
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