Horsepower ratings...

[atriop]

I have a question for anyone. I own a Stratos 268DC. that is a 16'8" Bass Boat. It's horsepower rating says max hp 140. which isn't enough to pull skiers... which I want to occasionally do. I have researched numerous replacements and have noticed that most newer 150hp motors weigh less than my 115 johnson and are the identical size, mounting, etc. What will happen if I go with a new 150hp motor? 10 more horsepower than Max doesn't really sound like much. I do not plan to sell this boat. It is my pride and joy...<br />Help???<br /><br />Scott

 

[JB]

Re: Horsepower ratings...

Scott, if 140 HP isn't enough to pull skiers behind a 16 to 17 foot boat you have a problem that 10 more horsepower isn't going to cure. I have pulled skiers behing a 14 Boston Whaler with 30 HP (rated for 40) and behind a 17 Boston Whaler with 70 (rated for 100). With a well-tuned engine, the proper prop, clean bottom, right trim and good weight distribution, your boat should pull 2 skiers at, or above 30 mph, which is VERY fast for skiing.<br /><br />Though 10 HP over a 140 rating would probably not cause you any problems other than provoking USCG who consider the rating law, It wouldn't cure any either. Check the above criteria and try the 115 again.<br /><br />Also, check your weights again. If your 115, which weighs about 350 (90 degree, cross-scavenged V4) or 325 (60 degree, loop-scavenged V4) is the "same weight" as a new V6 (400 to 600) someone is pulling your leg.<br /><br />Good luck.

)><br /><br />JB

 

[JB]

Re: Horsepower ratings...

Scott, if 140 HP isn't enough to pull skiers behind a 16 to 17 foot boat you have a problem that 10 more horsepower isn't going to cure. I have pulled skiers behing a 14 Boston Whaler with 30 HP (rated for 40) and behind a 17 Boston Whaler with 70 (rated for 100). With a well-tuned engine, the proper prop, clean bottom, right trim and good weight distribution, your boat should pull 2 skiers at, or above 30 mph, which is VERY fast for skiing.<br /><br />Though 10 HP over a 140 rating would probably not cause you any problems other than provoking USCG who consider the rating law, It wouldn't cure any either. Check the above criteria and try the 115 again.<br /><br />Also, check your weights again. If your 115, which weighs about 350 (90 degree, cross-scavenged V4) or 325 (60 degree, loop-scavenged V4) is "more than" a new V6 (400 to 600) someone is pulling your leg.<br /><br />Good luck.

<br />JB

 

[JB]

Re: Horsepower ratings...

Scott, if 140 HP isn't enough to pull skiers behind a 16 to 17 foot boat you have a problem that 10 more horsepower isn't going to cure. I have pulled skiers behing a 14 Boston Whaler with 30 HP (rated for 40) and behind a 17 Boston Whaler with 70 (rated for 100). With a well-tuned engine, the proper prop, clean bottom, right trim and good weight distribution, your boat should pull 2 skiers at, or above 30 mph, which is VERY fast for skiing.<br /><br />Though 10 HP over a 140 rating would probably not cause you any problems other than provoking USCG who consider the rating law, It wouldn't cure any either. Check the above criteria and try the 115 again.<br /><br />Also, check your weights again. If your 115, which weighs about 350 (90 degree, cross-scavenged V4) or 325 (60 degree, loop-scavenged V4) is "more than" a new V6 (400 to 600) someone is pulling your leg.<br /><br />Good luck.

<br />JB

 

[Dhadley]

Re: Horsepower ratings...

A 140 (either crossflow or looper) should be plenty. I had a 20 foot ski boat with a 140 that I could pull 2 skiers easily. You may want to think about a different prop to ski with. What prop do you use now? What top RPM? What x dimension?<br />Good luck!

 

[atriop]

Re: Horsepower ratings...

Thanks JB and DHadley for responding so promptly. I guess I didn't include all the symptoms. The Prop I am running is 13x20 Raker. It works really well for most applications. the boat runs about 50mph (speedo) in 1' chop or less. It also has a rather annoying tendency to cavitate whenever the slightes turn is introduced while running on plane. As far as the pulling skiers thing, I am about 6'5" and 245lbs. I am an amatuer skier so I probably make it harder on myself than possible. <br /><br />the Bottom line is, I want a motor that can function in both areas without changing props everytime I decide to change skiers. I gather that from your replies that a 140 would be good enough... More to follow...

 

[Dhadley]

Re: Horsepower ratings...

We still need to know the top RPM with an average load (not skiing) when hooked up and not slipping. Has your Raker ever been reconditioned? What shape is it in now?

 

[Capt Ron]

Re: Horsepower ratings...

If you have the boat insured some com******, if not all, will not cover the boat/motor if you exceed the HP rating. Also you may open up a can of liability worms by over powering. Have your present motor checked, I've repaired one that was a dog like your's before just by replacing the throttle cam roller. In short, the motor ran fine but lacked top end power. Check to see if you are getting full throttle first.<br />Capt Ron

 

[Dunk]

Re: Horsepower ratings...

atriop, first bassboats stink for getting out of the hole because most of the weight is in the stern. If the engine is running right your next choices are trim tabs to carry the stern better or dropping back in prop pitch just for sking. This will let her over rev if you try to run her wide open, but who skis at 40+mph? So the rpms will need watched when the smaller prop is used.<br /><br /> I would be conserned about the weight of a V6 on that boat. Your 140 V4 crossflow weight about 310lbs, a 150V6 is right around 400lbs. There are no laws about over powering a boat in any state. Like mentioned above insurance may be a problem. Most ins com****** will let a 10% over slide, but I'd get it in writting from them.<br /><br /> Another thing is that 140 was a weak engine at low rpms. If you compared it to a 90hp V4 the 90 would woulds swallow it out of the hole, but once on top the 140 will start to breathe better because of the bigger carbs and the more performance oriented exhaust tuner on it(bubble back V4's) and catch and pass the 90. Of course the 115hp gives you a little of both.<br /><br /> With that said I agree with what Capt Ron said about carb/ignition timing. Once the roller and the linkages get worn it gets the sync and link out of adjustment and this is super critical on these 140's to get all you can from them out of the hole. The sync and link check is what to say to your mech, he will know exactly what you/I mean. These 2 cycles engine need to have just the right of ignition advance to match the carb opening. I mean even off 2 degrees on timing cam will take the edge off her hole shot.