1998 Evinrude 6 hp 2 stroke

[bob24]

I was wondering if anybody knows what I need to do to modify my 6 hp to an 8 hp. Thanks

[Frosty]

Bob --you may be thinking that your 6hp is an 8hp de-rated?

It may well be,-- if your lucky. I dont actually know,- but if after checking that the carb does not have a restrictor plate behind it,- or the slide opens fully. it is unlikely to be worth the trouble investigating further. You will hardly notice the extra 2hp anyway.

[bob24]

Jack; Thanks for your reply. It's the same displacement motor and it appears to be a de-rated 8hp. I use it on my inflatable and it will plane the dink with me,(165#), my son, and some gear. Won't plane with my partner and gear. I have seen similar dinks with an 8hp, planning with 2 people and gear. When cruising we sometimes have to dingy some distance for supplies and planning the dink is faster and more efficient. Anyways was hoping that if I could get 2 more hp it would do the trick. I added a Doelfin Hyrafoil stabilizer early on and suprisingly it helped.

[redtech]

bob: most of the time you'll end up changing the intake, reeds, rejetting and sometimes replacing the carb and prop for two extra horses on this small motor cost might be cheaper finding an eight

[bob24]

Hi Redtech;
Thanks for your reply. I have aquired a carb, fuel pump, and reed valves. Reportably from an 8hp Evinrude that seized up after running straight gas. Hoses were still attached and everything looks new. After comparing it to the 6hp I noticed it used a primer set up instead of a choke. My 1996-2001 Seloc manual shows only choke fitted carbs for an 8hp. Also the fuel pump uses a hose for the vac/pres? instead of bolting to the block, but it still has the same casting but the hole isn't all the way thru. I have a carb number,(398060 MX 02 JL) if any body out there can reference it for me. My 6hp is a sweet motor with a short shaft and less than a 100hrs on it. I would like to keep it if I could. Thanks

[redtech]

this is just a differant model of the 8hp. all the parts can work with a little work.
there is a plug that screw into the block for the fuel pump, and then you'll find other set of mounting holes in the block for the differant fuel pump itself and use a pulse limiter at the bottom of the block for the fuel pump to run off of.
as for choke or primer this was dependant on the model. some people like the primer and others the choke your cowling already should have the plug in it for the primer
once done it will alway be eazy but seem hard till you've done it wish i was closer to connecticut so that i could be more help
good luck and stay light hearted

[bob24]

Thanks Redtech. I really appreciate the encouragement and the info. My 2 cycle knowledge is weak but I have rebuilt a couple of small gas inboards and and half dozen carburetors for my cars. That should give you some idea how old I am! :) Thanks again. I'll post the initial results when I get it done and when the weather finally warms up I'll load the dink up and see if it added enough hp to plane.

[bob24]

Hi Redtech; I removed the 6hp carb and compared it with the one I bought as a 8hp. The throttle plate bore and the choke side bore were alike but the venturi was a .100 smaller on the carb that was suppose to from an 8hp. I don't know why it would be smaller. Maybe it's not an 8hp? Could you check the the carb number ? (398060 MX 02 JL). I think the first 6 digit is the number. You sound like a pro so I'm hoping you have access to a parts book. I've searched the internet but couldn't find anything. The reed valves I got with the reported 8 hp were the same size as the 6 hp. Adapting the carb seems do-able with out too much work but I want to make sure it's an 8 hp. My local dealer is not all that friendly!! Thanks again

[redtech]

looking up carb numbers and i'll get back to you soon

[bob24]

Thanks Redtech

[bob24]

Hi Redtech;
I stumbled on to this website http://epc.brp.com/default.aspx?brands=ej&lang=E&dealerlocator=no
and found the carb that matches the number of the carb I bought. 398060 seems to be an 1987 6hp. Oh well. Many thanks for your help.
Bob

[lloyd]

i to have a 6hp evinrude 2 stroke. this is a great motor. i have heard that it is an 8 de-rated. how did the change over go. what all did you figure out that had to be done. thanks. there are 2 props avaible for this motor. what difference would they make?
thanks again.

[bob24]

Hi Lloyd;
I didn't do the change over. The carb I bought on ebay appears to be from a 87 6hp. Though Bombardier/ Evinrude parts list the carb number as a 6 and 8hp. My motor was a 98 and the throat was definately about 3/32 larger in diameter than the 87. Less air generally means less power. If you could find the right 8 hp carb for your 6 it probably would work. The link I listed in my 4/25 post is the factory part list and by using it and matching part numbers you could see what parts are diffirent. Finding a used 8hp carb proved to be difficult for my 98 and a new one is $250-300. In looking for a used one I found a like new 87 9.9hp for $500. Had to buy it. Sorry, now my sweet 98 6hp sits next my equally sweet 75 4hp. Guess I'm now a collector :) .

[lloyd]

bob24 i understand. lol. i have 2 eska 5hp's that are now waiting for a new addition to stand next to in the garage.