86 8hp mixture adjustment

[iwombat]

Anyone have any tricks, mods or unique tools to make this adjustment easier? It's just about impossible to get a screwdriver to the adjuster. Who thought that configuration up?

 

[jauguston]

Re: 86 8hp mixture adjustment

What adjustment are you trying to make? I have a 85 8hp and if they are the same and I don't know if they are the only adjustment I see is the idle mixture.

Jim

 

[iwombat]

Re: 86 8hp mixture adjustment

There's an idle stop, which is real easy to get to, and on the top and pointing horizontally to the . . .um . . . starboard side is the idle mixture. It's right behind a big lump in the air box. You need a screwdriver with a right angle in it to get to it. Removing the air box pretty much invalidates any adjustments you can make.

 

[iwombat]

Re: 86 8hp mixture adjustment

I was going to post a picture, but it appears the carb I have doesn't match the diagram for that year. It does match one for a '92, but my airbox doesn't. I think that's probably the issue right there.

 

[jauguston]

Re: 86 8hp mixture adjustment

I found out when I went to pick up my thermostat that I was mistaken on my 8hp being a '85. The parts manual shows the 8hp as only being built in '86.

I am confused on your description of there being a idle adjustment screw on the carb. My engine has no idle adjustment on the carb, the idle is adjusted with a knob on the end of the tiller handle.

 

[iwombat]

Re: 86 8hp mixture adjustment

That's the idle _speed_ adjustment.

I'm referring to the idle, or low-speed mixture adjustment, which on my particular carb and airbox setup is a nearly impossible to reach screw. I managed to sort of set it yesterday using a variety of screwdriver angles and and contortions. It's pretty close to where it needs to be, but getting it spot on just requires a bit more finesse and patience than I can manage.

 

[iwombat]

Re: 86 8hp mixture adjustment

Here's a diagram from an '88 which seems to be what I have installed. The red arrow points to the mixture screw. The blue arrow points to a protrusion on the airbox that sits right in front of it.

 

[jauguston]

Re: 86 8hp mixture adjustment

That looks nothing like my carb. My carb idle mixture adjustment is outside the cowl in the center between the choke knob and the starter handle. I'm new at this but I would guess your engine is not a '86 8hp. The '86 8hp is pretty close to the same engine as the earlier 7.5hp. I am using a 4.5-7.5 repair manual and almost everything is the same as the 7.5.

Jim

 

[iwombat]

Re: 86 8hp mixture adjustment

It's an '86 model # on the transom mount and the serial on the welch plug matches. I'm thinking maybe someone fit a later model carb on it for some reason or another.


Still, the original question still stands. Does anyone have any tricks or mods to make that screw accessable?

 

[jauguston]

Re: 86 8hp mixture adjustment

Is your model # anything like this:

E8RCOB
B100922

Those are the numbers on mine.

Jim

Also, that air box is nothing like mine either.

 

[iwombat]

Re: 86 8hp mixture adjustment

Model # J8RLCDE

That CO means yours is an 85.

 

[iwombat]

Re: 86 8hp mixture adjustment

There's a better picture of the adjustment screw in question. As you can see it's buried behind the intake to the air box. I'm thinking maybe I'll just drill an access hole through the end of the intake big enough for a small screwdriver. It's wide open already anyway.

 

[jauguston]

Re: 86 8hp mixture adjustment

Interesting. The parts book at the local dealer I got the thermostat from listed 8hp as '86 only. My ignition box has 62L as the last of the number as seen from the front of the box. Steelspike said that was a 6200 rpm limiter that was unique to that engine.

Jim

 

[iwombat]

Re: 86 8hp mixture adjustment

The BRP site lists the 8hp from '84-'02. Yours might be a late-model '85 with some '86 doohickies added on. Or, someone just replaced a bad one with a superseded part.

Also looks like the thermostat changed from 0378065 to 0393659 in '86. The old one probably wasn't available anymore which is why they only listed the one for the '86.

 

[jauguston]

Re: 86 8hp mixture adjustment

You may be right on the thermostat thing, the replacement was a completely different style.

Steelspike said he had a 84-87 repair manual. Maybe you can get him to see if it shows your carb.

Are you getting your information about this engine from a web site I can access?

Jim

 

[iwombat]

Re: 86 8hp mixture adjustment

http://www.evinrude.com/en-CA/Accessories/Introduction.htm

go to the literature section.