Evinrude 90 trying to get to run right some help Please.. runs real rough and backfi

No show · Oct 26, 2011

86 Evinrude 90 just purchased cheap and I don't wan't to throw good money after bad any help would be greatly appreciated.
owner said ran good till it sat. I'm more of a part changer than a mechanic but I do have the manual and did stay at a Howard Johnsons LOL
Ok It had no spark on the Portside was running on 2 cylinders. When I moved power Pack to left side It had Spark so I ordered a new one from here and some carb kits .

I put te power pack on tonight and It has spark on all four cylinders.
I put a new set of plugs in it and fresh fuel . started it up still runs rough and left plugs seem much cooler she backfires runs rough and shakes.
So I figured I'd give it a compression test results as follows Portside top =80 bottom=83 Starboard top=70 bottom =70 low but they don't seem that far off from each other. So what's the next move Carbs? Timing? I'm getting lil Stumped any suggestions welcome :facepalm:

boobie · Oct 26, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

Sounds like some carb work is needed. Does it backfire out the exhaust or are the carbs spitting back??

emdsapmgr · Oct 27, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

Those engines often suffer from a lean condition called a "lean sneeze." Not a big problem. Engine will idle, then missfire every 2-3 rpm's. If yours is doing that, it's a carb issue. You may have some debris (dried fuel) stuck in the idle passages of the upper carb body. You will need some strong stuff to dissolve that-usually a Gumout type carb cleaner product works well. You will have to take the carbs completely down for cleaning. Pull the jets out for visual inspection.

No show · Oct 27, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

backfires out exhaust, haven't touched carbs yet how does compression readings seem?

emdsapmgr · Oct 27, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

You may have two coil wires switched on one head. It will run with them switched, but you will get pretty violent backfires. The compression seems low. You may want to retest with another gauge. Maybe check the head gasket on the 70# side. Also, decarbing the cylinders may bring the compression up somewhat. See your Bombardier dealer for a product called: Engine Tuner.

No show · Oct 27, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

I doubt wrong coil wires,but I definitely check anything is possible. I was afraid to decarb it heard not good things about it.
The wires go to plug closest to coil .

emdsapmgr · Oct 27, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

I wouldn't worry about the coil wires to the spark plugs. Make sure the orange wires from the power packs go to the correct coils.

No show · Oct 27, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

That's possible. I'll switch them and decarb

No show · Oct 29, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

bump

Haffiman · Oct 29, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

Start with loosing your 'thank you' at the bottom of your posts.
Next, get the engine in a barrel with correct back pressure and not on the muffs.
Start it up and check engine temp on both heads. Should be around 140F. If colder, check/replace thermostats.

No show · Oct 30, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

Lost the thanks LOL .
wanted to do thermostats too. Don't want to take chances of overheating. getting cold here in Jersey. Didn't think about the barrel though. A lot less mud too. LOL

No show · Nov 3, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

Ok I used the Johnson decarb tuner and switched wires (small ones from power pack) still runs like crap. I did notice water pissing out was pretty cool to touch . rpms did come up and plenty of dark smoke. a couple of times it did run smooth for a second. I did take a video. please look at it. This time after a few minutes I did see smoke come from the round looks like a signal stat with red and yellow wires. I believe it's called the rectifier. got nervous and shut it down

http://s236.photobucket.com/albums/.../?action=view&current=VID_20111103_123739.mp4

emdsapmgr · Nov 3, 2011

Re: Evinrude 90 trying to get to run right some help Please.. runs real rough and ba

You have two threads going for the same engine, same problem. To get the best help from the members on this board, you should consolidate all the responses onto one thread so we can all keep track of the whole subject.

Evinrude 90 trying to get to run right some help Please.. runs real rough and backfi

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