Johnson props ?

[72INVADER90HP]

I have 1996 Johnson 90hp on a 1987 Bay hawk 18 foot center console boat, It has a 4 blade 15 pitch prop and it does about 25-30 mph and was looking at going to a 19 pitch. Will this affect the ride?

 

[Dhadley]

Re: Johnson props ?

It depends on a lot of things including what brand/style prop youre running now and what you want to go to. What are your rpm's now? What are you looking to improve?

 

[72INVADER90HP]

Re: Johnson props ?

I do not know that type of prop is on the boat because they is no name on the prop it just says 15. It is running 4500-5000 RPM right now, and want a little more speed.It is a 4 blade prop

 

[Dhadley]

Re: Johnson props ?

Something doesnt sound right. Lets look at your tach to make sure its on position 6.<br /><br />At 4500-5000 you are lugging the motor severly. Adding 4" of pitch would load it even further. A lot. Thats a very bad thing. <br /><br />Check your tach. Thats our starting point.

 

[72INVADER90HP]

Re: Johnson props ?

OK the 4500-5000rpm range I found out it is a throttle problem not a prop problemthis yesterday I was on the lake and only doing 4500 rpms and the boat was doing 27 mph I am right now trying to fix the thottle problem. I will let you know.

 

[72INVADER90HP]

Re: Johnson props ?

It is on potion 6, I want to increase the throttle but I am not used to the Johnsons motors. Where do I increase the throttle on a 1996 Johnson 90hp V4?

 

[walleyehed]

Re: Johnson props ?

The throttle plate shafts have roll-pin stops at the WOT position. I'm assuming it's rigged correctly???<br />I'm also assuming this is a 90 deg. X-flow.<br />The throttle stops may be different on the 94-up loopers...Dhadley will know...<br />Your 27mph at 4500 matches pretty close to my 115 with a 15" pitch, and I believe you are getting a correct reading there, but we've got 2 very different boats.<br />Mine is an 18ft alum deep-V, and I had alot of gear on board when I still had the 115.<br />It looks to me as though your speed/RPM ratio isn't terrible, but I would expect a higher RPM with that combo.<br />Follow Dhadley's advice when posted. He has vast experience in this area, and really knows the V4s better than OMC themselves did....