any one modded a 25hp merc?

[genea01]

if there is no rules then slap a 3cyl yammie on it but you can get the merc to run very good, if you are running mostly just top end slap you a 11x20 cleaver on it

[ber1023]

do they weight much more than 112lbs , as that wat the merc is and probably near the limit on weight. Id expect just over 50 with a 25hp.

[YAMAHAFASTCRAFT]

there weight is around 120 i think. you can do some serious mod. to that motor.

[50hptiller]

run the old style crank if you can its a lil lighter, lighten flywheel a little, lwp, several years ago a friend made some inserts to go in the combustion chamber to tighten it up, find you a horn, big carb, and a big cleaver........or find a 45sst motor and hang on for dear life.

[hydroplay]

Have seen a 25 Merc motor that Del Snyder built that had a removable cylinder head for more compression, some work on the ports and an external exhaust with a Konig Y-pipe manifold and an old Konig pipe. It ran well but eventually was sold to someone in Lousiana for use in jon boat races. Lots can be done if you are serious. Chrome bore can be ported and re-chromed.

[ber1023]

not that serious, how about a 30 johnson?? the 2 cylinder ones

[genea01]

not that serious, how about a 30 johnson?? the 2 cylinder ones

it is easier to get more hp out of the 31ci omc than the merc

[Seagull 170]

You'd better tell them about the water conditions you plan to run this in.

Not a lot of flat fresh water in Bermuda, (only in swimming pools) 40mph on south shore might be a very rough wet ride!

[MWhite]

Is this one yours? [lake Hopatcong last fall]

Theres several ways to look at making it faster. 1, Setup of motor/boat, height, angle, weight & its distribution. 2, Prop choice, a general prop made for the motor might not be working to potential. Luckily Merc offered performance options but a custom prop may be needed. 3, HP/RPM. mods can always be done but with 2 1/4 : 1, if you got 1,000 more R's out of the powerhead it would add up to about 5 MPH if you were using a 13" pitch prop. Larger pitch could increase that a little but its easy to over pitch a small motor & lose performance. Its being a deep V [?] is hard for the motor, they can be fast but it takes more.

man,



Man, I would like to run my 40 merc on that boat.

[JohnsonM50]

man,



Man, I would like to run my 40 merc on that boat.

Ive seen it a couple times, its really something. I didnt get to meet the owner tho. A 40 would be 'considered' to be too big sure but imagine that & a good speed prop. Some deep vees ride on a pad planed off, dont know whether these are v thru-out or padded.