Is newer 90 hp stronger than older 90 hp.

[mrtool2u]

I am currently running a 1986 Johnny 90 hp w/tilt& trim,and like most guys,I want a little more.(It trips my frog that my brother can out run me) I have a 19 ft aluminum Spectrum,which I really like.Would a newer 90 hp,like in the mid to upper 90's year range be noticeably stronger.If not,what could I expect with a 115 hp.Any and all info much appreciated,,,mrtool2u.

 

[ob]

Re: Is newer 90 hp stronger than older 90 hp.

What is your boat rated for?What is your WOT rpms with current setup?A newer 90 is no more ponies than the one you have.

 

[The Marine Doctor]

Re: Is newer 90 hp stronger than older 90 hp.

Both the engines you refer to are 90hp at the propshaft.<br /><br />TMD

 

[mrtool2u]

Re: Is newer 90 hp stronger than older 90 hp.

Actually,my boat is rated for 85 hp.It is actually not a U.S.C.G. rating,I believe that the boat maker put it on there,,because it was sold as a package with a 85 hp Force.I know that Bayliner had a lot of Force combos also.I have a friend with the same boat,and he was told that you could have it re-rated.It is a pretty good size boat,,82 in beam,19 foot, rated for 8 people,and over 2200 pounds.I know that this boat is very capable of a 115,,with a deep v and deep sides.

 

[OBJ]

Re: Is newer 90 hp stronger than older 90 hp.

Tool........shoot yer brother and take his boat..... <br /><br />Somebodies going to say somethin about this.....

 

[ob]

Re: Is newer 90 hp stronger than older 90 hp.

Did you want to see if you can tweek your current setup to increase performance or are you decided on a motor changeout?

 

[OBJ]

Re: Is newer 90 hp stronger than older 90 hp.

Tool....what ever you think about the capacity of your boat means zilch to the CG. If the rating sticker says 85...then that's what it is. Now....like ob said....you can tweek yer 90 and get a little more. Takes a little work.<br /><br />I have installed Boyesen Power Reeds on a lot of boats and havn't had a complaint yet. BUT....ya gotta follow the instructions. Should give ya' an extra 200rpms. (I got a 86' 90 Johnny to).<br /><br />Whats the set up of the motor on the boat? Where is the anti-cav plate in regards to the keel of the boat?

 

[mrtool2u]

Re: Is newer 90 hp stronger than older 90 hp.

First off,,shoot my brother hell,I will just lump his big but.OK,,the cav plate is about dead nut even with the keel of the boat.I had the boat weighed the other day,it came in at 1680# with approx 1/2 tank gas(8-9gal).Is my 86 year Johnny rated at the prop.What kind of mods are available.I only have 1 day of testing props,,with 3 big dudes in boat,,me-260,,my dad-225,,,and my bro-320.<br /> 13 1/4 by 17 OMC prop,4800 r's,35 mph....<br /> 12 3/4 by 21 stainless,,4400 r's about 35 mph.<br /> 13 1/4 by 15 older stainless(not cupped,5200 r's,,approx 35 mph.<br /> I have heard good things about the Ballistic prop,are they as good as they look,,cool looking prop.I have not been able to test props solo yet,possibly next week.I did a decarb,made no difference in comp. what so ever,120 psi each before and after.I am open to any and all advice.

 

[ob]

Re: Is newer 90 hp stronger than older 90 hp.

mrtool2u,To insure that you are getting the best out of the setup that you are currently running remove the intake silencer cover and have someone spin the rpop while you shift into forward gear.Advance throttle to wide open and insure that all carb flaps are opening fully horizontal.Also make sure that they then return to full closed.<br /><br />Your engine is best propped to turn in the upper range of its recommended rpm at wot.Any less (in your case) is causing the engine to essentially be lugged which will lead to higher operating temps and cylinder carboning.<br /><br />The 15" is getting you close but 5500 would be better.Once you've checked out the carb flaps I would consider raising the engine on the transom to achieve optimal height.This process will require water testing to insure that excess prop ventilation does not occur at 2/3 throttle while executing a tight turn.You'd like to get the engine mounted as high as possible without this occuring as it will afford the least drag and exhaust back pressure.Sometimes you can gain between 200-400 extra rpms by performing this procedure.Added r's = more speed.Once the final height adjustment has been made you can then reseal the transom bolts one at a time.Best case scenario is that you may be able to run the 17" prop at higher than previous rpms and incite a sibling rivalry.

 

[OBJ]

Re: Is newer 90 hp stronger than older 90 hp.

And tool....you ain't gonna beat anybody with all those "heavy dudes" in the boat.

 

[ob]

Re: Is newer 90 hp stronger than older 90 hp.

 

[mrtool2u]

Re: Is newer 90 hp stronger than older 90 hp.

O.B.,I assume that I should lift the engine 1 hole at a time,which equates to 1 inch.I have checked the throttle linkages and they are opening the whole way,,,but I have not did the process with the silencer cover off,I will try that,,why would you need 2 people.Is there that much to be gained by lifting the motor.Would a Stingray or a Cobra Edge be recommended for this type of set-up.Any and all info much appreciated.

 

[ob]

Re: Is newer 90 hp stronger than older 90 hp.

Two people = one to turn the prop and one to shift throttle control into forward gear.this prevents binding of the shift linkage which can cause damage if forced.Unless you have a really long leg. <br /><br />The amount of edge to be gained by raising motor to optimal height will vary depending upon the amount you are able to raise it.Say if in your case you could gain 2" of height on the transom without causing excessive slippage ,you would surely notice some improvement in wot rpm and overall handling.The procedure that I listed above is fairly standard practice when initially coupling a motor to a given boat.