evinrude 50 hp no power

[elpayin]

my 50 hp evinrude had been running fine since a bought it but all of suden while cruizin` @ 25 knots it lost power and it can only run @ about 5 knots!
when i accelerate the rpms go down and the motor just loses power.
sometimes for a few seconds sounds and feels like it`s going back to normal (accelerates) but then...no power! seems to me like carb is flooding or carb needs some cleaning.
if that`s the case, should i use a especial carb cleaner?
any other advice?
thank you.

 

[Quick-man]

Re: evinrude 50 hp no power

I have a 75 HP that I am trying to diagnose with the same issue but I loose spark in one of my cylinders, so I know what the issue is, just not teh cause of the loss of spark for a breif period of time. You can check spark with a simple spark tester from an auto store, check all cylinders. Since the motor is running good but suddenly dies it could be a fuel issue as well. Is the primer bulb hard? Do you have another fuel tank and hose with bulb to try? Start with the easy things first, check that fuel is being delivered, a good carb maintenance additive is Seafoam, you can get that at AutoZone and similar places. Try to mix up a gal of the stuff and use an external tank if you have an inboard tank so you don't have to use tons of Seafoam. But the engine has to be running well for that to work.

 

[Chris1956]

Re: evinrude 50 hp no power

El Ceck the compression on all cylinders. It should be 100+PSI, and all within 10% or each other. Check to see that all carbs open fully at WOT. Post Model number for further help.

 

[elpayin]

Re: evinrude 50 hp no power

the model # is: e50belcic and, yes the bulb gets hard,
the thing is that when i run it out of the water with the hose, seems to work better but still a little "shaking"
i`m gonna check the spark in the plugs, compression, and use my other gas thank to use the seafoam etc,and i`ll post the results.
also, which is the best spark plug for this motor and what is the spark plug gap?
thank you, thank you much.

 

[Quick-man]

Re: evinrude 50 hp no power

I rebuilt my carbs this year as I just bought this engine and it had a slew of issues, including no gaskets between the exhaust housing and powerhead, dirty carbs, and a bad powerpak, just found that out when I replaced it, it runs great now.

Does the engine run any better with the choke part way on? That is a sure sign that the carbs are getting dirty, My engine directly injected gas into the carb throat and that is the only way it would run consistantly.

Check for compression, spark, make sure the sync is set and that the carbs open completely when you are at WOT.

If it was running good then stopped running good, I would look at compression and spark, get new plugs, just to make sure you have all that first. I lost spark intermitently and it was difficult to diagnose without breaking the bank. Used parts are a good alternative try ebay, that is where I picked up the powerpak.

 

[chbailey]

Re: evinrude 50 hp no power

So sounds like the carbs. Are you saying the compression and spark is ok? Check out my thread on all the problems I was having. http://forums.iboats.com/showthread.php?t=208295

 

[Jacob645]

Re: evinrude 50 hp no power

How do your coils look? Any cracks? Maybe take them off because sometimes their hard to fully inspect when they're still on. While they're off go ahead and clean the grounds. I have a 1975 50hp that did that. I put two new coils on it and ran some seafoam spray through the carbs for good measure, and now it runs great. If you DO get new OMC coils, make sure that you check for the spark jumping through the new boot! For some reason when I installed mine, the spark plug boots were bad (the ones they had in the kit). If they do jump spark, it won't run right! Good luck!