25hp omc

[bobvdinghyracer]

recently a referal came to me an wants to go faster with his mini hawk ... anyways i am not real familar with these as i am more into mercs tho i just did a 35hp rude which is the same block ... (point ign ) thru hub ex... the 1 i`m lookin at now is cdi was told first yr suposed to be a 77 ... also mite add non thru hub ex ... i have not seen it run ... he tells me that no matter what prop is on it ( a 9p / 10/p 11/p also had a 13/p all 2 blade ) it runs out a 5000 rpm .... and says runs well he believes it has a rev limiter built in ??? any body kno ???? and if so any way around it ??? seems to me either it has a limiter or theres some other problems somewhere , the other motor i dealt with was the higher hp version (35hp ), from what i`ve picked up on these sites is only diff is carb / intake cover ... the 35 went on to a funski and is a real bear as compared to him telling me the 25 will go at best 28-30 no matter what he does ! any input guys ???also seems to me it should be a thru hub ex ?? or did they offer it as pin drive in 77 or does he have a cob job this an that someone put together
if its in vain ... he wants me to build him a merc 40cuber , what say you ??
thanks

[Chairman]

1977 was the first year OMC used the 31.8 cube powerhead for the 25hp. But it was over-the-prop exhaust. Went to thru hub in 1984 or 1985.

The only rev limiters I've seen are built into the power pack and are set at 6100 rpm. You'll find the number 6100 printed right on it. The remedy is a non-limited pack. Just look for one with the same wiring configuration as the original.

Also, you'll know it if you are hitting a rev limiter, the motor repeatedly cuts out at a rate of about twice a second or so.

[JohnsonM50]

Actually, 77 was the 1st year of the 25hp but the 31.8 - 35hp came out in 76. Im pretty sure all of them are cdi's. They looked just like the pin drives but were splined prop shafts [25's] I think all 35s were thru-hub. Some 25's had plastic carb inserts as a de-tune to 25 effect. Ive heard of but never seen a power pack that limited rev's on one, If you change the carb, set the time to the 35 spec, With prop changes it should respond with rpm change. Ive run them into the upper 6's & more. If what you have is a pin drive & has magneto ignition its most likely the older 22 ci motor, up to '76. Good Luck

[JohnsonM50]

[QUOTE=Chairman;93563]1977 was the first year OMC used the 31.8 cube powerhead for the 25hp. But it was over-the-prop exhaust. Went to thru hub in 1984 or 1985.

The only rev limiters I've seen are built into the power pack and are set at 6100 rpm. You'll find the number 6100 printed right on it. The remedy is a non-limited pack. Just look for one with the same wiring configuration as the original.

Also, you'll know it if you are hitting a rev limiter, the motor repeatedly cuts out at a rate of about twice a second or so.

The 6100 in the # is news to me & might explain a thing or 2 Ive heard of an R. Thanks

[Chairman]

It looks something like this:

Also, the 1976 35hp had points ignition, all since have been cdi.

http://www.dillon-racing.com/images/Picture%20014b.jpg

[JohnsonM50]

It looks something like this:

Also, the 1976 35hp had points ignition, all since have been cdi.

http://www.dillon-racing.com/images/Picture%20014b.jpg
Thanks.

[DonChichoJr.]

The omc 35 hp, manual start, 2 cyl. : Cdi , no limiter pack : #113-2285


don;)

[BRIAN HENDRICK]

recently a referal came to me an wants to go faster

Mr. Bob;
-maybe its in a previous post, but could you
quickly explain your insane avater ;)

-looks like a 99" 6 ???
-a Merc dingy?
-what size/type??

[OUTBOARDER]

recently a referal came to me an wants to go faster with his mini hawk ... anyways i am not real familar with these as i am more into mercs tho i just did a 35hp rude which is the same block ... (point ign ) thru hub ex... the 1 i`m lookin at now is cdi was told first yr suposed to be a 77 ... also mite add non thru hub ex ... i have not seen it run ... he tells me that no matter what prop is on it ( a 9p / 10/p 11/p also had a 13/p all 2 blade ) it runs out a 5000 rpm .... and says runs well he believes it has a rev limiter built in ??? any body kno ???? and if so any way around it ??? seems to me either it has a limiter or theres some other problems somewhere , the other motor i dealt with was the higher hp version (35hp ), from what i`ve picked up on these sites is only diff is carb / intake cover ... the 35 went on to a funski and is a real bear as compared to him telling me the 25 will go at best 28-30 no matter what he does ! any input guys ???also seems to me it should be a thru hub ex ?? or did they offer it as pin drive in 77 or does he have a cob job this an that someone put together
if its in vain ... he wants me to build him a merc 40cuber , what say you ??
thanks

They are putting 50hp engines on the Mini Hawak v hulls to go fast.

[JohnsonM50]

They are putting 50hp engines on the Mini Hawak v hulls to go fast.

If that means the little boat in the avatar, that could ;) be insane.. At some point you wont gain the speed if ya dont stop the hop LoLs:D Have a blast trying:cool:

[bobvdinghyracer]

the pic is a model 270 quicksilver inflatable (8.5 feet) outside ... wood floor insert ... rated 10hp in pic has a merc200 .stock . runnin mid 30`s at time ... it is too much on tiller :eek:thats why steering is in it ..and a deadman throttle . now using a 200 slitly ported on a mark 20 leg striped to min. weighs in at 68 lbs ... with mich 3blade bronze 7 1/4 x 12 pitch runnin 40ish gps :), annual race at end of season ( last 5 yrs) 5 wins :) oh yeah forgot to mention she does not hop !40 is pretty much its limit with a soft bottom it has a funny feel to it at that speed ... gettin too old to get dumped outa it . just picked up a gt invader .. wait till ya see what i put on it

[JohnsonM50]

the pic is a model 270 quicksilver inflatable (8.5 feet) outside ... wood floor insert ... rated 10hp in pic has a merc200 .stock . runnin mid 30`s at time ... it is too much on tiller :eek:thats why steering is in it ..and a deadman throttle . now using a 200 slitly ported on a mark 20 leg striped to min. weighs in at 68 lbs ... with mich 3blade bronze 7 1/4 x 12 pitch runnin 40ish gps :), annual race at end of season ( last 5 yrs) 5 wins :) oh yeah forgot to mention she does not hop !40 is pretty much its limit with a soft bottom it has a funny feel to it at that speed ... gettin too old to get dumped outa it . just picked up a gt invader .. wait till ya see what i put on it
I didnt think it really had 50hp.. could be scary.:)