how fast /new powerhead /

[Benny1963]

i know theres no way to tell without certain detail
i have a 17ft mckee 1981 hull is dry and slick fresh gelcoat
its rated at 140 hp i have a 150 mid with a fresh 175 crossflow powerhead,
tuneing is near perfect havent pulled up the rpms yet due to break in .
i had the 150 powerhead on it the last time i ran it it went 49 mph on gps
but two cyls were low on comp from overheat 60 lbs and 70 lbs the others were 110 115 115 110 ,it also had calapssed piston skirt and wrist pin damage but ran well,i have know jetted up to the 175 jets on my 150 carbs
im running a evinrude 21 pitch prop stainless my 150 was only pulling
5400 damaged my new goal with new powerhead 5800 to 6000
with boysens im running xp heads what do yall think this thing will run mph
proped for 5800 to 6000 or do you think the 6000 is obtainable
how fast will it go and what do you think the hull design will limit out at
it is a skiff sort of a wahler design
just wanting any info even just theories it also run smart tabs
thanks just playing around

 

[Dhadley]

Re: how fast /new powerhead /

You need to get the 150 jets back in the 150 carbs.

 

[Benny1963]

Re: how fast /new powerhead /

hi mr hadley the powerhead is a 175 030 thought i needed to go up
how are ya doin thanks for the help on this powerhead rebuild its been a while ,so you sayin i should run the 150 carbs with the 150 jets except the changes for the boysen
thank you

 

[Benny1963]

Re: how fast /new powerhead /

hi mr hadley the powerhead is a 175 030 thought i needed to go up
how are ya doin thanks for the help on this powerhead rebuild its been a while ,so you sayin i should run the 150 carbs with the 150 jets except the changes for the boysen
thank you

 

[Dhadley]

Re: how fast /new powerhead /

The 149 cid, 2.5 liter 150 and the 175 crossflow use the same block, port timing, bore, stroke, intake, ignition etc. The difference is the 175 uses a slightly different carb body and is rated at a slightly higher rpm. Not to be confused with the rpm range they advertise, it's the actual rpm they rate them at from the factory.

If you run 150 carbs, run the jets that came in them. You'
ll find different jets in 150 carbs in different years but the carbs are different. Stay with the jetting that came in the carbs. If you get over 6200 then you might have to start rejetting. Regardless of which carb you use.

 

[Benny1963]

Re: how fast /new powerhead /

thanks i will stay with the jetting in the 150 carbs my boysens are in and i will have to make some changes for them i believe there tech line will help me in that area , or if you suggest something for my boysens then i will do that
i want to push this motor to 6000 for sure but that will be more than enough
the boat is not performance ,its a mckee with smart tabs it over rated
now it had a 150 on it it was rated for 140 but now my 150 mid has the 175 powerhead but im not going to get stupid its already to fast just wanted the motor make as much hp as possible the boysens claim to idle better and
i would frather have a fiber reed go thru my motor than a metal one
plus i want to push 6000