1985 90 hp evinrude fuel problem

[spooly]

ok guys here's the deal...engine has sat up for several years,pulled and rebuilt carbs w/new kits,all new fuel lines,new impeller,gearcase lube,engine cranked but had to push in choke regularly to keep running,cleaned fuel pump,re-cleaned carbs but still have to push choke to keep running,was able to get boat on plane and engine ran good but as i slowed down engine would die...replaced fuel pump....no help...any ideas

 

[64osby]

Re: 1985 90 hp evinrude fuel problem

http://forums.iboats.com/johnson-evinrude-outboards/top-secret-file-updated-8-1-2012-a-299680.html

Lots of great info there. Did you adjust the carbs after the rebuild?

 

[multimech]

Re: 1985 90 hp evinrude fuel problem

Check the fuel pressure. Check the compression. Check ignition (hitting all, all of the time) Recheck the carbs because you may have missed something or gotten more crap in them from, say a dirty fuel tank. Pushing in the choke and having the engine pick up and run is usually a sign of a blockage in the carb. Check to make sure you don't have an air leak in to the engine. This usually allows engine to run well at high speed ( not indications until it blows) but will cause a lean sneeze or die out or erratic running at lower speeds. If it is a crossflow engine, in my experience they are more prone to this type of thing ( more parts to leak). Without more info can't really say more.

 

[emdsapmgr]

Re: 1985 90 hp evinrude fuel problem

Sounds like the engine runs fine, except at idle. Likely a fuel/carb issue. When that engine idles, the carb butterflys are completely closed. The fuel supply at idle goes through very small (dedicated) idle passages in the carbs. These tend to get blocked/restricted by dried fuel over the years. Once these get restricted, the engine just won't idle right. As soon as you crack the throttle, even a little, other jets will supply fuel and the engine may run just fine. Some carb cleanings won't handle the dried fuel (gel) from inside these hidden passages. Sounds like you need to pull the carbs down again, and spray an aerosol carb cleaner (like a Gumout type product) through the idle passages-then reassemble. You'll want to spray one passage on one carb, noting the exiting spray pattern. Then pick up carb #2 and do the same passage, noting the exiting spray pattern. Both should have the same exiting spray pattern. Then go on to the next passage on carb #1, etc, etc.

 

[kenmyfam]

Re: 1985 90 hp evinrude fuel problem

Does sound like a low speed jet fuel restriction.
VRO / OMS fuel pump ?? or premix ???

 

[spooly]

Re: 1985 90 hp evinrude fuel problem

rechecked compression...good 110 on all 4,rechecked spark good on all 4(could light a cigar),ALL new fuel lines,premix w/fuel pump from 88 spl,new gas/oil in remote tank,re-cleaned with aerosl cleaner,pryer to that had let soak in BERRYMAN carb and parts cleaner for 3 hrs,gonna tear down carbs again and re-soak...let ya'll know what happens

 

[stylesabu]

Re: 1985 90 hp evinrude fuel problem

if carb bowls dried out, varnish can form and most cleared won't clear it out without a little help. I use a wire tie off a bread bag,and strip paper or plastic off wire and use cleaner along with wire.

 

[emdsapmgr]

Re: 1985 90 hp evinrude fuel problem

Did you remove all the fuel jets in the carbs the last time you cleaned them? A good idea to visually inspect them during an overhaul. Those carbs have 2 each idle jets, mid jets and high speed jets in each carb. You will need a special screwdriver to get the high speed jets out of the bowl.