www.iFourWinns.com

Last season I bought what I thought was a good starter boat. It is a Horizon 180 with 150 HP Ocean Pro. It is my first boat and I didn't have anyone to help me make an informed decision so I kind of went in blind. We did a water test and it seemed to run good so I bought it. Being new to boating I mostly concentrated on the basics of learning how to boat until now when I started reading on this forum. My boat runs about 4000 RPM and 36 MPH WOT (which I rarely run at). The engine heats up to 200F if I run much over 3000 RPM so I mostly cruise around. I dropped it off at a local boat place at the beginning of the season and explained all this and asked them to go over the boat and let me know what they thought. After keeping the boat for over a month they changed the impeller and decarbed it and said it seems to be running fine. They didn't water test it. After searching this topic a bit more I am really concerned that I could be harming this motor by continuing to run it like this. I believe all the cylinders are firing, because the spark plugs look ok and when I removed one plug wire at a time they all reacted the same (rpm changed and could hear clicking in cylinder with wire off). I plan to buy something to check the compression soon. It currently has a 14.5 x 19 RH prop which I assumed caused the low RPM due to being over propped. I don't really care about getting more top speed, but I definitely don't want to harm the engine by just continuing to run like this. Any advice you guys can give would be greatly appreciated.

According to the Four Winns "Fast Facts" ( http://www.fourwinns.com/customer-service-catalogs.aspx) your boat came with the 14 1/2 x 19 aluminum prop, and the boat had a top end between 43 and 46 mph. It shows 42mph at 5000 rpm and 44 at wide open throttle. A compression test would be a good idea, and is not hard to do. The high operating temp is unusual, and could come from several sources. It could be from an obstruction or problem in the cooling system, or from combustion gases leaking into the cooling system (maybe a head gasket or cracked block). Do what you can troubleshooting, but you may need to have a shop dig into it. You might even need to look at a different shop if the one you have used is not able to identify and correct the problem. You might look for a repair manual either in hard copy or online (maybe http://boatinfo.no/lib/library.html# ). Hope this helps, and best of luck.

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Surface Interval: A scuba diving term for that time between dives to relax and prepare for life's next great adventure.

Current boat: '02 FW 268 Vista
Previous boat: '95 FW 190 Horizon

There are a number of reasons why the engine might not reach the specified max rpm. Fuel system issues are commonly seen causes. Fuel filter, vent, and anti siphon valve are all things to check. At the end of each season I remove the fuel filter and dump the contents into a Mason jar. Let it sit and see if there is a layer of water on the bottom, if so the gas tank may need to be cleaned out.
Keep in mind that there are three things that are critical to the life of 2 stroke marine engines:
Cooling system, make sure it is not overheating
Fuel mixture, make sure it is not too lean
Oil injection, make sure this functional

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88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

Looks like the Fast Facts shows the 150HP outboard to have a top end of between 43 and 46 MPH, not rpm. Looking at the fuel flow data, it appears that WOT is well above 5000 rpm.

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"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

Thanks, Ray. I was "multi-tasking" (getting interrupted by) with the new puppy and goofed while quoting specs. Its corrected.

According to Fast Facts that boat came with the 14 1/2 x 19 aluminum prop, and the boat had a top end between 43 and 46 mph. It shows 38 mph at 4500 rpm, 42 mph at 5000 rpm, and 44 mph at wide open throttle. Fast Facts shows about 4 mph increase for each 500 rpm increase, so wide open throttle should be in the general area of 5250 rpm.

One question I have is whether you are trimming the outboard up at faster speeds and at top end. I assume you are trimming up at higher speeds, but have seen some people that had no idea it made a difference. It has been my experience with the 190 Horizon I/O that the boat would gain at least 10-12 mph at top end by trimming the drive up. It is also more efficient at cruise with trim.

_________________
Surface Interval: A scuba diving term for that time between dives to relax and prepare for life's next great adventure.

Current boat: '02 FW 268 Vista
Previous boat: '95 FW 190 Horizon

Thanks for the responses. It sounds like it's not as simple as over propped like I hoped. I'll try to do compression check this weekend and post results. How can I check the vent and anti-siphon valves. I'd also like to pull the thermostats and see if I can find anything. At low rpm it stays at 160.