changing from 4 stroke to 2 stroke

newhaul · #1 (**permalink**) 09-30-2010

i currently have a 1997 v8 horse honda 4 stroke engine on my ib 24 looking to change to 2 stroke (easier to work on) what size 2 stroke should i use
also the honda wont fit in the well on the boat i am looking to get rid of the o/b bracket

sailingdog · #2 (**permalink**) 09-30-2010

You have a 8 HP four-stroke, why not get a 8-9.9 HP two-stroke to replace it. That would be lighter than the four-stroke and give you about the same HP or a bit more. You'll want a High Thrust prop for the outboard though. Most 8-9.9 HP two-strokes will fit in the outboard well, since the well was probably designed for a two-stroke outboard originally.

Quote:

Originally Posted by newhaul

i currently have a 1997 v8 horse honda 4 stroke engine on my ib 24 looking to change to 2 stroke (easier to work on) what size 2 stroke should i use
also the honda wont fit in the well on the boat i am looking to get rid of the o/b bracket

newhaul · #3 (**permalink**) 09-30-2010

thats what i was thinking the vessel was made in 1966 however as with most islanders from that age i cant find any info on what engine was recommended by factory spec. as far as weight my friend has an 18 hp evinrude and it weighs less than my Honda. I'm looking to get plenty of power but get rid of as much of the weight as i can. thanks for the prompt reply.

dabnis · #4 (**permalink**) 09-30-2010

Newhall,

I had a 15HP 2 stroke Evinrude, same size and weight as the
9.9HP, on a Coronado 25. Worked great, the 9.9 may have been
enough? Don't know what your well configuration is but if you
do some measuring beforehand you should have an estimate as
to whether it would fit. Suggest you get a long shaft version.
The high thrust props were not available then so we went down
an inch or so from the stock prop and had all the thrust we could use.
We used the motor hard for 10 years with no problems.
On my present 2 stroke motor I switched to synthetic 2 stroke
oil, same 50:1 ratio, and the smoke was noticeably reduced.

Dabnis

tommays · #5 (**permalink**) 09-30-2010

Well

If you live in the US the 2 stroke thing is only gonna happen used

If outside the US you may be in and area were there still legal to buy new

mitiempo · #6 (**permalink**) 09-30-2010

It's not illegal but Evinrude does not make a small engine anymore.

dabnis · #7 (**permalink**) 09-30-2010

Quote:

Originally Posted by newhaul

thats what i was thinking the vessel was made in 1966 however as with most islanders from that age i cant find any info on what engine was recommended by factory spec. as far as weight my friend has an 18 hp evinrude and it weighs less than my Honda. I'm looking to get plenty of power but get rid of as much of the weight as i can. thanks for the prompt reply.

Newhall,

I didn't see your last post before my last reply. Your local Craigslist
may be a good source for a used motor.

Dabnis

Cruisingdad · #8 (**permalink**) 09-30-2010

I bought my 15hp 2 stroke yamaha around April of this year. Yamaha discontinued production on them the summer before, but many dealers are still sitting on them. Shop around and see if you can get one from them. The new 2 strokes are super engines.

sailingdog · #9 (**permalink**) 09-30-2010

It is a 24' boat... it really doesn't need more than 9.9 HP to move it.

Quote:

Originally Posted by newhaul

thats what i was thinking the vessel was made in 1966 however as with most islanders from that age i cant find any info on what engine was recommended by factory spec. as far as weight my friend has an 18 hp evinrude and it weighs less than my Honda. I'm looking to get plenty of power but get rid of as much of the weight as i can. thanks for the prompt reply.

Gladrags1 · #10 (**permalink**) 10-02-2010

i agree with sailingdog. A 9 hp is all that is needed to move the boat. I had a Catalina 22 with a 9 hp 2 stroke ob motor which pushed her just fine!

Tod