This is the first twin engine center console i’ve had so i dont know if all of this stuff is normal or not. Its a proline 23 sport 2002 model with twin 150 xr6 engines. The engines both heat up quick at 2000-3000 rpm. Also its hard to keep the boat on plane under 24mph and does not feel good under 30. Usually this doesnt bother me but im gonna try some high speed wahoo trolling. Trim tabs and motors all the way trimmed down and front boxes full of ice i can keep it on plane about 21mph feathering the throttles at around 2800 on each engine, but its only a few degrees from turning the buzzers on and according to the gauges both engines around 220 which i dont think the gauges are right. This boat feels good with the engines 4000-4500rpm 35-40 mph. Is it just made to run good on the top end or should the motors be moved up or down to help with this problem? If this helps wide open i run 5600 rpm both engines with 17 pitch 3 blade stainless props. Usually 46-48 mph. Seems like it should be a little faster as well. I put the big exhaust tuner, boyesen reeds, and all of that good stuff too. Runs better and smoother and better fuel economy but no faster. Had the above problems before i did the extra’s.
Have you put new water pump kits in yet? Typically if you get an overheat at that range, but then goes away as speed increases it is because of a low water flow due to a poor performing impeller. At low to mid speed the impeller does not pump enough water so the engine heats up. As you increase speed though you get more ram effect into the water pickup which helps give more water flow and the engine cools down again.
Iain Pelto
Edgewater 185CC “Jumpin’ Bean II”
Yeh, the impellers are both a year old, did the same thing right after changing them just like before. ???
I have the exact same problem with Merc EFI. I assume its impellar from dry starts.
Fishing on the bottom is like having sex with the lights turned off. It feels good… but I wanna see it.
Lights On!
2002 Sea Hunt Triton 210
150 Yammy SS II
could be a bad poppet valve.
The poppet valve and I have been to war already. I rebuilt the left engine two years ago and the collar thats staked in the block that the poppet valve goes in came out. That took me a couple trips to the lake to find. The thing that gets me, is that both engines do it.
Hmm, thats got me wondering. Poppet valve huh?
My motor has less than 20-30 hours on it and it has been doing it since it was practically new.
Fishing on the bottom is like having sex with the lights turned off. It feels good… but I wanna see it.
Lights On!
2002 Sea Hunt Triton 210
150 Yammy SS II
Im starting to think that the 2.5 block has a water flow issue. That would be the same block at your 200 efi. Maybe they just dont have the capacity to cool at this rpm when its not on plane. I would really love to pull some stuff at 15-20 mph. I might plumb my wash down hose into the engine flush port while on the lake just to see if i am actually not flowing enough water.
I had the same problem and mine was Poppit Valve. They are designed to open with pressure at higher RPMs and dump water. If they are stuck and not popping open, the water in the block doesn’t get out quick enough.
Rick
I am not familiar withe the term Poppit valve but is that what you are calling the thermostat?? Thermostats in outboards do go bad and are set up for a particular job of running wide open or at idle speed. Maybe you should go to a cooler running thermostat where it opens up at a lower engine temp thus forcing more water through the block. Just a thought. Good luck!!
Rog
“Double Trouble”
2001 Sea Fox 230
2001 Merc 200
poppet valve is the mercury term Yamaha calls it a pressure relief valve. The valve opens at a certain water pressure and allows excess water pressure at higher rpms to bleed off. debris around the valve and seal or a weak spring could cause a lack of water pressure at lower rpms.
The thermostats only control water flow to maintain temperature at slow to medium speeds. After that the thermostats are fully open and it is the poppet valve that controls flow.
Iain Pelto
Edgewater 185CC “Jumpin’ Bean II”
the blocks have the ability to flow enough water to keep them cool
thats why they have to put in the thermostats, to stop them from over cooling.
based on what you have already done, my guess would be corrosion gunk/jelly in the heads/cooling passages
pretty common
when the boat is plowing, the engines are working extra hard, and the only water the engine is getting is from the waterpump, and the rpms are fairly low
when the hull planes off, the waterflow is being assisted by the highspeed water forcing into the intake, plus the engines arent lugging.
if you have a minor restriction in the water passages, this would be the result
I’m now at www.teamcharlestonmarine.com
Thanks for the lessons in poppit valves and thermostats. I learned something new today. Thanks!!
Now I can go back to sleep.
Rog
“Double Trouble”
2001 Sea Fox 230
2001 Merc 200
Thanks ChrisV. That makes very good sense. When i built the left engine and changed the exhaust tuner i did not notice any blockages or major corrosion, but then again i wast looking for it. It still baffles me that both engines do it. I’m gonna get my laser temp gauge out and see how accurate these gauges are because the temp needle is burried past 240 when the buzzer finally comes on. I remember on the lake in the winter time at good cruising speed these engines actually dropped below 140 at times. Wish i still had that problem in the the summer.
sounds like to me the motors are too high on the transom. The XR6 engines are designed for light bass boats, they are not my first choice for what you have, but they will get the job done if rigged correctly. All the mods you have done are great for light weight boats, but probably have made your problem worse. Drop the motors down a couple of holes and switch to four blade wheels after you have the cooling issue taken care of. If you are planning on running the boat in the plow mode for your “high speed wahoo mode”, drop down a couple of pitches in prop or your going to be replacing power heads on a regular basis. Running a boat at plow speed is like driving your car in high gear, up a hill, with a load, and a trailer hooked to it, at 15 mile an hour, its probably teh worst thing you can do to a boat, otehr than let it sit.
quote:
Originally posted by sparepartssounds like to me the motors are too high on the transom. The XR6 engines are designed for light bass boats, they are not my first choice for what you have, but they will get the job done if rigged correctly. All the mods you have done are great for light weight boats, but probably have made your problem worse. Drop the motors down a couple of holes and switch to four blade wheels after you have the cooling issue taken care of. If you are planning on running the boat in the plow mode for your “high speed wahoo mode”, drop down a couple of pitches in prop or your going to be replacing power heads on a regular basis. Running a boat at plow speed is like driving your car in high gear, up a hill, with a load, and a trailer hooked to it, at 15 mile an hour, its probably teh worst thing you can do to a boat, otehr than let it sit.
Just from eyeballing the engines they are high in relation to the bottom of the transom. They are in the second to highest hole now so i will try going down two. The four blade wheels will probably give me more lift in the back to also assist my porposing problem and keep the transom from riding too deep im assuming. When going from three blade to four should i go up down or same in pitch??
i Wouldn’t worry too much till you get teh motors down and hopefully it will fix your heating problem(probably sucking in aireated water). Once you have the heating problem fixed, go see Skips propeller, he might have a set that you could try, its hard to say when switching to four blades, there are so many variables other than just adding a blade. The Merc Offshore or Turbo +4, would be agood start. I don’t think the Trophy or any other four blade with a lot of rake will be what you need, you need diamter and blade surface.
Lowered my engines two holes, new water pumps, and took the thermostats out. The best the boat has ever done. No overheating. Planes out 16 mph even gained 1mph on top end because i can bring my trim tabs up more with out porpoising. Boat handles better, drives better, and is better my opinion. Ran it w/o thermostats before i did the lower. THis helped a little bit but only about five degrees. The lowering is what really did the trick. However i never run too cool without the stats. Will put them back in when it cools off. About 160 is where i stay now. Thanks to spareparts and chrisv. You guys are awesome.