260 or 280

[acil meyer]

Has anyone put a jet pump on a 260 or 280? They're putting pumps on 300xs-250xs but the weight is too much for my boat. I would like to have more hp without the weight. I am running a 200-2.5efi now. thanks ace

[Jay Smith]

Not sure if you'd be real happy with a motor that makes its top HP and torque well above the top rpm ( 6000 ) a jet pump is efficent.The 280 would build more torque lower than a 260 IMO ( the port mapping on a 260 is 1" .565" and the 280 is lower at 1".610" = more torque @ lower rpms) Also the 280 is a bit heavier and has a much higher cap. charging system....Most motors I've build for jets are the 240 Sport Jet motors. Also make sure that your drive shaft spline coming off your jet is a match to a normal outboard crank 260,280 ( V-6 Mercurys ) the 240 Sport Jet has a different spline and will NOT mate up to the 260,280 crank...

Jay

[acil meyer]

Hi jay
so jay what is out there for motors that i can get more hp with out the weight .I am not running a sport jet but a outboard with a pump on it . or can you make my 200efi make 250 plus hp thanks ace

[Jay Smith]

Most of the time increased HP on a 2 cycle entails raising the rpms and thats not what you need. I did build a 260 a month or so ago for a customer that was going to jet pump it. I did everything I could to bump the low end torque because I knew the pump was done at 6000 . I cut the heck out of the front half stuffed the block and bumped compression. Haven't heard yea or nay ..

Jay

[acil meyer]

jay if you talk with the person that you bilt the 260 and see the numbers he is getting out of it did he put the new large pump on the motor if he likes the setup . That sounds like the set up i need.
thanks ace