9.9 to 25hp..possible or not???

[Cberry]

Check out:<br /> http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=26454&item=2406456704&rd=1 <br /><br />I've got parts..how to build one??

 

[dkondelik]

Re: 9.9 to 25hp..possible or not???

I'm EXTREEMELY sceptical.<br /><br /> http://www.pugetsoundanglers.org/Fishing Info/Johnson 9.9_15.htm <br /><br />I think that this is the best you can hope for starting with a 9.9 AND still have some reliability/dependability.<br /><br />Good Luck<br />HAVE FUN!

 

[Cberry]

Re: 9.9 to 25hp..possible or not???

"EXTREEMELY sceptical."....Me too.<br />Looks like a lot of "machine shop" time<br />would be involved. A possible format like<br />that could produce 35hp in 9.9 clothing.

 

[Big Al1]

Re: 9.9 to 25hp..possible or not???

HP is HP is related to exhaust pressure. It looks as if the 9.9 upper unit is combined with a 25hp lower unit. This achieves an exhaust pressure the same as a 25hp but I doubt it produces 25hp. If it would, I bet it ain’t too reliable.

 

[FlyBoyMark]

Re: 9.9 to 25hp..possible or not???

Hmmmmmm...Most 9.9's are similar to 15's and a tuned exhaust pipe produces at least 33% more power....20 hp reliably is easy to attain with stock rpm....more would require over reving and port work and maybe a bigger carb, different reed induction.....Anybody ever dyno a souped up 9.9 or 15?

 

[Chinewalker]

Re: 9.9 to 25hp..possible or not???

It's simply not possible. It's relativley easy to make a 9.9hp into a 15hp of similar vintage starting with a swap of the exhaust tuner and carb, but getting 25hp out of the 13 cuber is a pipe dream. Even the racing guys aren't getting that kind of power out of the 15A motor, and they're spinning them at 7000 revs through a 14:19 gearcase. I think the seller in this auction has either been misled or is confusing his 15 for a 25...<br />- Scott

 

[Neptune]

Re: 9.9 to 25hp..possible or not???

Hi Ship's Rat,<br /><br />Methinks something is amiss here as well. Could just be a 25 cowling rebuilt in 2001 with 9.9 decals? Who knows but it would be fun to buy it just to find out! The price does seem attractive IF it is in fact a good motor.

 

[OBJ]

Re: 9.9 to 25hp..possible or not???

I suppose all things are possible but I'd sure like to see the throat on that carb!!!!!!

 

[Hooty]

Re: 9.9 to 25hp..possible or not???

Ya gotta remember, those 9.9's were built for lakes requiring engines of 10hp and less, No tellin' what some of those things would dyno.<br /><br />c/6<br /><br />Hooty

 

[OBJ]

Re: 9.9 to 25hp..possible or not???

Good point Hooty. But do ya' thing you could get enough CID out of a "9.9" to make a 25. If ya' did, how long would it last? I think you would really be pushing the limit here.

 

[Boatist]

Re: 9.9 to 25hp..possible or not???

Ships' Rat<br />You should buy it then call Bombardier and let then know you can show them how to convert a 9.9 into 25 HP and still only wiegh 74LB. I sure they would pay millions for that design. Yes you can convert a 9.9 to a 15HP by installing the bigger carburetor. If want 15 HP at the prop then also have to put in the tuned exhaust. If it sounds too good to be true then it is. The motor probably one all they did was change the high speed jet and now does not run right so after 4 hours decided to sell. Would you sell it 6 hours after you rebuilt it and got 3 times the HP?

 

[Cberry]

Re: 9.9 to 25hp..possible or not???

"Would you sell it 6 hours after you rebuilt it and got 3 times the HP?"..... HE HE HE HE!!<br />Not me!! I'm gonna follow up on that motor..<br />we'll see if it sells ...and if so what kind<br />of credibility seller retains!! I've only been wondering if it was a secret formula that some of you "gurus' have been keeping to yourselves and as<br />I have lots of parts, and with the secret could build my own. Ciao!!

 

[romanspapa]

Re: 9.9 to 25hp..possible or not???

I have a 9.9 Mariner with a 15 hp carb on a 15'7' Gheenoe that I will race him with.

 

[roscoe]

Re: 9.9 to 25hp..possible or not???

I emailed the seller and asked what was done, what parts were replaced, how much it cost him, included a list of parts from the powerhead to the prop. I got this response:<br /><br />"The engine was converted professionally at a boat dealership. I told him what I wanted and he said it could be done. The only thing I can tell you for sure is that he swapped the carburetor out and made a lot of adjustments. Wish I could be more specific, but it runs great and it is really fast. Good luck bidding"<br /><br />I guess he doesn't know, or aint saying.

 

[OBJ]

Re: 9.9 to 25hp..possible or not???

If all he did was change out carbs and make a lot of adjustments, I would be real skeptical. Sure it wasn't a typo and was supposed to say 15hp and not 25?

 

[digimortal777]

Re: 9.9 to 25hp..possible or not???

id say its a 15, or near 15b , not a hope in hell your gonna get 25 horses out of that unless u squeez a 25hp power head in there