joe reeves or expert help! 1972 25hp

Joe, a friend told me about how you are a marine motor expert and i seriously need some help. Well, the motor is a 1972 25hp evinrude sportster with less than 20 original hours, long story but i insist it is very true. the motor started right up and looks great,everything really clean. i recently put it in the water for the first time since getting it 3 weeks ago and like i said it ran great, in idle, until i put it in forward. well it idles great in forward but will not go to full throttle at all in forward. maybe just 1/4 throttle. i have cleaned my high speed jet and compression is 105 on both and i just got new j4s gapped at .030. what do i do now? when i put it all back together it started for about 3 seconds shut off and now i cant get it started again. help! i am just getting into this outboard mechanics and could use some advise. thanks bossman!

Re: joe reeves or expert help!

Compression is okay. If you have spark, it would appear that you are overlooking something in the carburetor department.

On that model, the spark should jump a 1/4" gap with a strong blue lightning like flame... a real SNAP! Does it?

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)
Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note 1: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

Note 2: If the engine should be a three (3) cylinder engine with three (3) carburetors, start the adjustment sequence with the center carburetor.
When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

Re: joe reeves or expert help!

thanks joe! it runs like a dream. you really know your stuff man. now, one more question......i have a really WIDE 16' modified v with a double hull all fiberglass boat from the early 80's...i will attach a pic to show you. the fiberglass is really thick and im thinking the little boat is too heavy.......it DOES put it up on plane, but barely. also im 320 lbs. and my buddy is 350 lbs. haha could that also play a factor in why its not "hauling tale"?

Re: joe reeves or expert help!

That is quite a bit of weight for a 25hp, no offense intended. What you might try (if available) is a four (4) blade prop which will greatly increase the torque of the engine but will not affect the top speed to any great degree.

By torque, I mean it will increase the power to get out of the hole and on a plane.

Re: joe reeves or expert help!

is there anything else that i can do to increase top speed with the 25hp other than throw my fishin' buddy off the boat or loose weight? maybe a seeting or something that could help, i dont know? if i could find somebody that would trade my 16' fiberglass for a 16' wide aluminum that would help increase top speed right?

Re: joe reeves or expert help!

Other than the four blade prop I mentioned (if it is manufactured), you could purchase the lowest 3 blade diameter/pitch prop which is a 9"x9" propeller, part #379717 . But first check to see what you already have on that engine. If your present prop is a higher pitch, the 9x9 would be a help getting out of the hole and up on plane.

The alternative is a higher horsepower engine.

Re: joe reeves or expert help!

thanks for the expert help joe.