ya at wide open it runs 5500 rpm if the gas line is to big will it suck more gas or only use what it needs ?The old rule of thumb for fuel comsumption is 10 % of the hp at WOT. So a 120 hp mtr would use 12 gal per hr. Sure you didn't go more than 2 miles ? Sounds like your mtr is running okay hitting 5000 rpm. Range is 5000 - 6000 rpm.
so in 4 mins flat out you burnt 8 gallons of gas. 3/8 gas line syphoning takes longer than 4 mins for 5 gallons. have you got a lot of oil on the inside of your cowling?
for prop help firstly you will need gps for speed (hand held and some phones can do this) then weight of boat (the coast gaurd sticker max weight will do) what rpm you was running at what speed. does it have trim and tilt. what was water conditions. how did it handle and what the prop on the motor is now (you will have to remove the nut to see the prop numbers that are printed around the center).
best numbers are trimmed out max speed max rpm and prop.
if you are new to boating it may be you have the trim set wrong and most of the power is then lost. then again maybe im special and the only one dumb enoght to do that.
hello so prop is 13x19 boat is 1500lbs and runs wot at 5500 rpm with a top speed of 28 mph what would be a good prop size / pitch for this boat to get mor top end speed not looking to do 50 but somwhere in the 30s would be good i dont do any towing and would only have 4 guys in it at a time thanks for all the reply so farYour Oil tank should be dropping as well, make sure your VRO is running right.
I have a 86 120HP, and it's great on gas compared to my old 77 140HP and way better than my buddys 175HP merc. The 120HP only required 5/16" ID fuel line (thats what it would have came with stock). But i've replaced mine with 3/8" ID line and would recommend it. i have a 19' open bow edson and we cruize all day (approx 8hrs) on 90 litres. Once the kids get bigger and start getting into water sports and bringing their friends out i'm gonna have to put on a larger motor.... i'm thinking a 175HP, but until then i'll enjoy the 4 cyc fuel consumption.
- look on your prop and get us the part number at the least but size and pitch should also be stamped on it.
- also ensure you antiventilation plate is at or 1" above your keel (ensure your engine is sitting in the right place before you start messing with props)
- for my setup i use a 13.25 x 17P for cruizing and fishing and light watersports, but when i'm bringing out 6 or 7 people and the tube i throw on a 13.25 x 15P. top speed is a bit lower but way better for a heavier load. both props are michigan wheel, purchased from iboats.
cheers
well i dont know about high 40's but i know it uses a lot of gas and moves slow i did drill a hole in the floor today to see if the foam had water in it someone must have put a new floor in at one point because there was no boat foam in it and there was a lot of water in it my boat does not have a drain hole in the bulk head to drain water that may get in where the foam is so i drilled one and let the water out i have know idea how much water was in there but im hoping it makes a diffIs that speed from a GPS or speedometer because 28MPH is way off? With a 19" prop turning 5500 RPM your speed should be mid to high 40s. Something doesn't seem right.
No not that I have seen I'm only guessing we went 2 miles the bay we are on has a light house that is said to be 1 mile from where we started from it runs fine idles at 1000 rpm and runs wot at 5500 rpm just seems like it uses a lot of has that's all will take it out and run on 8 g of gas infill I run out and see how long I can go. What about prop size and pitch any ideas there?
