2001 115 hp Johnson o/b

[sharkin95]

I have a 2001 seaswirl 1851 WA with a 115 johnson 2 stroke I'm getting 5,000 rpms at full throttle but my mph is only 29 mph. I'm thinking slipping prop? or what else?

 

[Docksidemarineservices]

If the prop was slipping(cavitation) you would be seeing more than 5000rpm.

 

[sharkin95]

yea I kinda thought that to. thanks

 

[faztbullet]

Sound a lil under powered...whats the HP rating???

 

[sharkin95]

2001 seaswirl 1851 WA my engine wot is 5500 but I should be getting at least 32-35 mph I have read with a 135 hp engine it hits speeds of 40 mph. The weight of the boat is 2350 lbs The compression is 150 on all 4 cyl.engine. bottom is clean....max engine power is 150hp

 

[faztbullet]

25hp is a big difference in speed. Your engine has the small diameter gearcase so run the biggest diameter prop you can. Your speed is about right for the 115...

 

[sharkin95]

My 2001 Johnson engine #J115VXSIC v4 loop chrg. 60 deg. thanks for the reply running a 14 3/4 x 17 pitch ss prop ......any suggestions for a better prop?