2001 ERude 6HP install 8HP carb?

[Dizz]

Bought this motor very slightly used about 8 yrs ago.Put it on my 12' wide Alumnacraft jon.
Will plane off with mild load,aprox 325lbs people,some gear.With 2 adults and more gear it will not plane off.
The year after I bought it(it looks new)I went to OMC dealer,looked thru the parts books,and bought a new 8HP carb,and maybe a backing plate to adjust advance on timing,not sure on the plate,but all the different parts for the 8hp were bought.
I could tell very difference in low end power,maybe a little more rpm`s.Dissapointed to say the least.I did all he could find to do,still starts&runs smooth&great.
Any thing I missed in this up-grade?Dealer told me the 6/8hp series because of the small displacement had much less low end power than the 9.9/15 series,and I need the 9.9.I have a 15hp on a bigger boat,but want to use the 56lb motor on this boat because of sliding it down river bank,no triler.The 15 with electric start is closer to 80lbs.
I have not tried it out this new Solas 8x7 prop yet,but the stock prop on the 6/8hp is a OMC 8.5x9 pitch,is it likely I`m going to see a nice low end gain from this lower geared prop?
So to sum it up,did I miss something on the 6 to 8hp conversion,and will this prop help it plain,I realize I will loose 2-3mph on top end,assuming it planes out,and a boat that don`t plain will not do over 7mph anyway..

 

[ondarvr]

You wouldn't gain any low end with a bigger crb, might even lose some, but the actual HP difference between the two isn't much, so it may not be that noticable at top end. I'm not going to look at the parts diagram for each to look at the differences, you can do that. The prop may help, but you need to know the actual RPMs to dial in a prop.

 

[Dizz]

For last 30 minutes I looked up the actual part#`s for both motors.Appears he did not look deep enough years ago,when a new carb was $140,now it`s closer to $500,guess it`s a antique now,so vintage price boost! ​When I compared other parts,like exhaust housing,oil sump,cylinder head,none of the part#`s are the same,for this 2001 model 6hp,compared to same year 8hp.I just wasted the money,and gained a few rpm`s.
Since the weak 6 hp would not plane it out,rpm`s didn`t matter,right?
Since this is the only other available lower pitch prop,it wouldhave to help,right?

 

[TN-25]

I just looked up the 2001 Evinrude outboards and discovered that all the small portable Evinrude motors were 4-strokes that year. I also discovered that they sold a 5 and a 6 horse that were based on the same displacement but the 6 had a bigger carb, making the 6 a hot-rodded 5. I also saw that the 8 was actually a completely different powerhead with a larger displacement ( = more torque to get up on a plane). I guess I hadn't been as familiar with the newer stuff as opposed to the older stuff.

Are you positive it is a 2001? Is it a 2 or a 4-stroke? They did make a 7.5 horse 2-stroke for many years starting around 1980 that they later rated at 8 hp, then dropped to 6 when the prop rated horsepower became the new rating standard. They actually sold a 6 & 8 horse 2-stroke pair based on the same block around 1996/97.

I would think that your motor should be able to push a 12" jon boat if the motor is in good shape, has good compression and is tuned up. What is your boat horsepower & load capacity? If it is rated for, say, 15 horses then you would be asking a lot from a small displacement 6 with a larger carb. To plane you have to get over the hump, and if you are propped too steeply the motor may never get on a plane, it may overheat and work far too hard. A shallower pitch prop will help your motor if it is struggling to get on a plane. I am not an expert, but what I generally see is that the smaller diameter, steeper pitch props are great if you have a lighter, faster hull. If you are having trouble getting onto a plane though, the larger diameter, shallower pitch prop should work better. The Solas 8x7 prop is worth a try. If the current prop won?t let your boat plane then the theoretical top speed loss is just an imagined thing anyway.

With lower torque from a smaller engine, a shorter pitch prop will give it the leverage it needs for the RPMs to climb and start to make actual horsepower. With the bigger carb that you have it may even help the motor realize some high RPM power increase and improve things. Watch out that you do not exceed you motor?s maximum RPM range though.

At the risk of sounding trite, a larger motor could solve the performance problem and be more efficient since it doesn?t always have to strain itself nor be under-propped to achieve some revs. If weight is an issue and you are running a 4-stroke, consider a 2-stroke. The RPMs rise faster because every stroke is a power stroke, plus they are significantly lighter due to not having a valvetrain (cam, timing chain, fulcrums, valves; plus the head casting is more complex). For example a modern 9.9 4-stroke weighs the same as the old 18-25 horse 2-strokes of the 1960s to mid 70s.

 

[Dizz]

Sorry,I have the year all wrong,thisis a 96 model I think,model# is E6REDS,and Ithink when I look up the 6,and 8hp par#`s,I may in fact find my dealer was correct,Iread that some reed valve exhalst,or manifold things had to also be changed to take the 6 to 8hp,I will look that up tonight.
This 1236 boat is rated for up to 15hp.
I do have a 15hp electric start,but as I said above the 6 is much lighter(both 6,and 8hp weigh 56lbs)(9.9 and 15 hp weigh 72-78lbs)and easy to carry down a bank,and put on the boat in the water.
This 6hp has not over 40hrs on it since new,and in Great shape.

 

[TN-25]

Well I see. In that case, if you are going to fish with a buddy and some gear, get that 7" pitch prop on it and see what happens. Best of luck!

 

[interalian]

If you're fretting over an extra 20 pounds for a more powerful outboard, get a stronger friend.

 

[Dizz]

I know when I retire,I will be much fishing by myself .​When you unload all the stuff from yourboat in pickup,slide the boat over the bank,then walk to the back of the boat while it`s in the water,only 1 person can make that walk.
I also have a 57 Johnson 3hp twin,that is very light.

 

[raczekp1]

i had in my hands 6 and 8 hp model made in years 1980-1990.
the 8 hp modal has bigger hole in carb mounting panel