1975 85HP Evinrude-Starved for Fuel

[Mostly Harmless]

Hey guys, first time poster looking for some advice. I am attempting to get a 1975 85HP Evinrude to run again after an 8 year break. The last time this engine ran it started up and idled fine but when you gave it full throttle it wasn't going nearly as fast as it use to. I believe this issue to be a stuck carb that I found when disassembling parts of the engine. So far I have done the following

• Replaced ignition coils
• Replaced Power pack
• Replaced Rectifier
• Clean the heads (replaced gaskets)
• New battery
• Replaced fuel pump
• Replaced water pump
• Cleaned contact points in the stator

I seem to be getting spark across all four plugs (checked by holding the plug against a ground and verifying that a spark exist) but I don't smell gas on the plugs after cranking if for a few seconds. I have not rebuilt the carbs and suspect they might be dirty (they should have gas to them because I see gas is filling up the lines running to the carbs). How likely is it that the leaf valves might be stuck? Is there any way to verify if they are working with out pulling the manifold off? Should I start with cleaning the carbs first then work on the leafs? Thanks for your help.

 

[R.Johnson]

Re: 1975 85HP Evinrude-Starved for Fuel

I'm not even sure if it's possible for a leaf valve to stick. The reed valve is stainless steel, seating on a aluminum plate. More than likely you need to clean the carb's, and install new kit's.

 

[iwombat]

Re: 1975 85HP Evinrude-Starved for Fuel

Its amazing how many people jump right to the reeds as being the problem. A bad reed is a pretty rare bird. Dirty carbs are a dime a dozen.

 

[crb478]

Re: 1975 85HP Evinrude-Starved for Fuel

After 8 years! Clean the carbs. If you want reassurance spray some pre mix in the carb throats while cranking, I bet it will fire.

 

[Mostly Harmless]

Re: 1975 85HP Evinrude-Starved for Fuel

I definitely did jump the gun on blaming the reeds, mostly from some outside (bad) advice. I was planning on cleaning the carbs but I have never worked on them before and I was a bit hesitant (this is my first boat that I got three weeks ago). I wound up buying the carb rebuild kits, took them apart, clean them both up (lots of build up) and the engine fired like it was brand new. Thanks guys.

 

[CaptOchs]

Re: 1975 85HP Evinrude-Starved for Fuel

I definitely did jump the gun on blaming the reeds, mostly from some outside (bad) advice. I was planning on cleaning the carbs but I have never worked on them before and I was a bit hesitant (this is my first boat that I got three weeks ago). I wound up buying the carb rebuild kits, took them apart, clean them both up (lots of build up) and the engine fired like it was brand new. Thanks guys.

If the problem comes back, buy a fuel filter water separator. You could have some water in the fuel and that will cause this problem. I had the same issue. A marina had my boat for a YEAR and they couldn't figure out what was wrong with the engine. I replaced the engine and guess what, same thing started happening to the new engine. I cleaned the carbs and the engine ran great for about 10 minutes, and died down. It struggled to plane. I cleaned them once more and put a fuel filter/water separator and I haven't had the problem since. It stinks I sold my old reliable Merc 65 dirt cheap when it was the gas.