1991 johnson / evinrude 8hp not getting fuel, carb issue

nem_bee

Cadet
Joined
Aug 12, 2016
Messages
6
91 8hp evinrude 2-stroke, which should be similar to the 6hp in a lot of ways. Picked it up as-is and after a lot of frustration now I'm beginning to suspect someone previously might have put carb together missing parts or something... the part's site exploded diagram is helpful and I haven't found anything missing. I've tried to go over every part carefully.

Will run on starting fluid or if premix squirted into cylinders or intake. Have checked the fuel pump output & it's working. Carb rebuilt, and been through it about 5 times. The float part of the carb works, as in the bowl fills and shuts off flow when full. squeeze the primer bulb and bowl fills up and flow stops. The main jet, the slow speed jet, and the other orifices are cleaned with air and carb cleaner, and weren't plugged at all to start with. The idle mixture screw is 1.5 turns out. The float and the pickup move freely. The small hose isn't jammed, although it does sit at a bit of an angle. The air vent in the carb is clear. The cam follower and roller (throttle) is adjusted within spec and the choke & linkages are working.

It won't fire at all unless I try to run it on premix (spray bottle in the intake)or starter fluid, and it won't stay running after that, so somehow it's not getting any fuel,

Short of buying a whole carb, ANY thoughts, advice, or pointers on anything I should check or might be missing, would be greatly appreciated. I've searched the web & been to 'leroy's rambling's' web site and couldn't find specific carb photos like there are for other models, so any links to photos of the carb internals or similar would be helpful as well.
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,720
ITYWF that the idle mixture screw initial setting should be 2½ turns out *, but probably not the trouble

Throttle opening OK?
Choke closing OK ?

If you don't have an OEM manual you might find something useful in this manual http://www.boatinfo.no/lib/evinrude/...inrude.html#/0

General tune up instructions in section 1 and carb overhaul instructions in section 3

** Carb set up specs in the table at the end of section 3
 

nem_bee

Cadet
Joined
Aug 12, 2016
Messages
6
thanks so much. Finally got it running, likely combination of factors... 1) a link rod to the choke knob was on backward so may not have been fully closing choke... not obvious without close inspection 2) the "nozzle well" may not have been sitting down all the way or similar, due to the small "flex tube" position. 3) 2.5 turns instead of 1.5 on idle mixture screw...actually after warming up and tuning by ear in gear, it seems like around 2.75-3 turns is the sweet spot for whatever reason, on this one. Wouldn't idle at all closer to 1.5-2 turns...

This is the "less common type b carb with removable top, found in some pre 1993 5,6-8, and 9.9-15hp and most 20hp" The manual Vic linked was slightly better than the more generic one I was referencing.
 
Top