Jet on a art-178 or Lowe?

[eddie162]

Anyone running a Jet pump on a Ranger RT-178 or equivalent Lowe or G3? I put a jet pump on my Yamaha 70 HP and can’t even get the boat to plane out. I have an Atlas 4” hydraulic jack plate but still won’t plane or run flat. Top speed is @ 18 mph and it takes forever to get it to that. Any suggestions?

[rangerman942]

I have an Rt188 with a jet, but mine is a 150/105. I believe there is only minimal weight difference between the 178 & 188. A jet knocks about 30% off your horsepower, so your motor now is equivalent to a 49hp. After running mine with a 150/105 I would not have wanted to put a pump on a 115 and ran it on my 188, it would have been equivalent to an 80hp. These are heavy boats. The dealer I purchased mine are jetting 115’s and hanging in the RT178’s. I’m sure there is some tweaking you can do to make it better perform but you may have to ask a pro. Years ago when i owned a dealership we would jet 200’s and 225’s and mount them on 18-19’ boats with 56-60” bottoms, you can never have too much hp when running a jet.

[eddie162]

I’m not so worried about the speed as the lift. It just won’t plane out and run flat which defeats the purpose for which I bought it. I’m thinking maybe trim tabs but I hate to drill more holes in the boat.

[T-Mac]

With jet outboard rigs, how skinny you can run depends mostly on the shape of the hull, and the weight to horsepower ratio. The faster you can go, the skinnier you can run...period.
A wider , flat hull on a light boat with the most horsepower reasonable works best. . Jack plates and set backs are not your friends with jets. With a jet outboard you want the front of the jet foot ( intake) just a hair above the bottom of the boat and close to the transom. My own jet is a 1754 with a 60/40 jet.. very plain (to keep it light) ..54" bottom width made of .100 ga. aluminum. It runs about 30mph at best. Trimming is just physically pretty minimal....even on my boat which weighs probably 250-330 (?) lbs less than yours with gas and gear. I sold a lot of them... and it was qquite a learning curve in the beginning.

[eddie162]

I kinda wish I hadn’t spent the money on it now. I’m just trying to figure out a way to make it work now that I have. I want to be able to get across shallow shoals but right now I can get just as far up with my prop unit.

[rangerman942]

Send me a PM with your phone number and I can send you some photos of the foot distance in relation to the boat/transom and you can compare it to your set up. My dealer also ground off the wedges on the bottom of the hull.