I have a 1985 150XR-2 the hole shot needs improvement as last year I hade some problems getting two deep water footers out of the water.Looking at the spec's for the 150 and the 175 they look the same except for the piston size.Would it make any sence to bore out the 150 to get it up to 175.Would this give me a better hole shot or is thier a better way.I have two props a high 5 and a regular 21 pitch.Oh yea why is the 17.6 only rated for 165 hp when the 20ft's are getting 3 200's or better on them. Just wondering if anyone has some ideas??? Thanks and see on the water Pete
Try moving down to a 17 or 15 pitch for more hole shot and watch your rpm on the high end. You really need a 2.5 liter motor which I believe is a 91 or 2 or later. jim
The engine only has abuot 700 hrs on it not to beat.I realy want more Hp than it is rated for at 165 I think it is silly this boat should be able to handel a 200 at least I think.
Realy I just need to find a good merc tech close buy the house here so that I could ask some tough ????
The Coast Guard has a mathematical formula based on the boat dimensions to determine the limit for an outboard powered boat less than 20 feet long. It has nothing to do with the capability of the boat. If you do a search you will find a lot of discussion about the unfairness of this rule. The 20's and the inboards are exempt from this rule and it is up to the manufacturer to determine the limit if there is one. It is my guess that you will find it cheaper and much better to replace the powerhead or even the motor than to hop it up. The prop advice I gave you is relatively cheap if you experiment with an aluminum prop or a used prop from eBay. It will work. A modern 150 with the right prop will have all the performance you need. There is a thread of one here towing a kite. The new 150's can produce up to 165hp at the prop. jim
I know I'm a bit late but now is an excellent time to buy a one season old ski team motor for a great price. There are some here from must ski motors and also some on showskiers.com There are two issues here. 1. Does your boat go fast enough 2. Does your boat have enough pulling power. These are totally different issues. Issue two has NOTHING to do with horsepower. It has to do with torque, something your old Merc with its small displacement and high horsepower tuning can't produce. A 150 E-TEC with the right prop will pull 4 or more slaloms out of the deep on your boat no problems. A prop change will also help your current engine do much better. Just like Jim said. If you want to go faster you need more horsepower. If you just need more torque, you need a more torquey engine. Improving your's isn't worth the expense - unless you can achieve what you want with a prop change. The 150 E-TEC is a 2.6 litre motor and it is tuned for torque. It makes at least as much torque as the 175 and 200 small block E-TEC. Horsepower is typically produced at 5000+ RPM. Your merc is probably more like 6000rpm to make its 165 horsepower. At 3000rpm skier pull out type RPM you'd be amazed by how much power it DOESN'T make. It is probably similar to the amount of power a 90hp v4 engine makes at that RPM. High performance "tuned" motors like your XR don't make torque. Take a look at viewtopic.php?f=18&t=1204 In short if you need more top speed, you will need more horsepower. If you are happy with your current top speed but just need more grunt to get there you need a bigger displacement engine of the same 150 horsepower. Also of note, the process of direct injection produces additional torque - about 5-10% extra. The 150 E-TEC will produce as much mid range torque as ANY 200hp 2.6 litre or ANY naturally aspirated (non supercharged) four stroke 200hp engine. I have a 225HO 3.3 litre E-TEC. I have pulled 13 skiers from the deep with the same prop that will pull over 64mph. Honestly you wouldn't believe how much better these new engines are. And if you can get Erich's 150HO you'd be very happy. Greg
