Offshoreboat
Seaman Apprentice
Thread starter- Joined
- Apr 27, 2002
- Messages
- 30
Hello does annybody can tell me the difference between my 100 HP and the 115 an larger engines?<br />Thanks on advance<br />Offshoreboat
<br /><br />I did some looking into this, and I can't say this definatively, but the research I have tells me that the 85HP and the 100HP have the same capacity.. (92.6 cubic inches I think.)<br />the 125 had 99.6cu,, don't know about the 115.<br /><br />bore and stroke on 85 and 100: 3.375" x 2.588"<br /><br />apparetly max hp was at 5000rpm, but rated to 5500.<br /><br />Those figures are for the 71 rude range, but they are the same for the 72 as well I belive, and back then there was no diff in powerhead for rude and johnny..<br /><br />Hope thats of some help, if you were thinking about trying to up the power to 115.. I wouldn't, you could probably do it, but this motor is either a tuned 85hp or the 85 is a detuned 100hp.<br /><br />of the former is true, its not designed for 115, if the later is true, its certainly possible, but its not a bolt on affair, you'd have to modify carbs, exhaust, reeds and stuff like that.. not an easy task.. (porting would help to) but all of that would cost more then a replacement motor and your 100hp may spit a rod trying to cope with the extra HP, (particularly if its already a "hyper tuned 85.)<br /><br />just some thoughts,, I was toying with adding boyseen reeds to it, and measuring top speed before and after. maybe you should do the same.<br /><br />rgds<br /><br />frank