1987 50 hp rough idle

[boling]

Model E50TLCUD, low hours (less than 100). VRO has been bypassed. Runs about 3 times a year. We took it out Monday ran a wot for at least 20 min, it cut out a couple of times after hitting some rough water. It idles rough now.

Checked fuel output from the pump while cranking...good

Sprayed carb cleaner in both carbs while running....upper carb, little change, lower carb moter dies.

Both plugs have the correct gap and are firing.

Thinking about ordering carb kits for both, and stabil in the gas from now on.

Anything else could be wrong here?

Thanks for any help.

Chris

 

[Dennisanoka]

Re: 1987 50 hp rough idle

boling-

Not saying you wouldn't benefit from re-building the carbs but I would suggest before doing that, would be to run some more tests to better determine what the real issue is. It sounds like it's not firing on all cylinders. I'd determine which one is not firing and then find out why, spark, fuel issue or compression. By what you wrote it may be the top that's not firing, rather than using carb cleaner try spraying in some pre-mixed fuel if it picks up you may indeed have a fuel,carb issue but I'd still do some more investigating before doing the carb kits.

 

[boling]

Re: 1987 50 hp rough idle

Forgot to mention, while idling rough, pushing the electric choke/primer makes it smoother. Would that be the same as spraying pre-mix in the carb?

Chris

 

[Dennisanoka]

Re: 1987 50 hp rough idle

Normally if you were to prime it as it was running it would choke and cough alittle. The fact that yours runs better indicates that it is starved for fuel. Sounds like you are on track for a carb rebuild kit.
Do a search on this site for a post/article by Joe Reeves: Carb cleaning and follow it closely, especially cleaning each jet, port, and oriffice with a wire to really clean out the gunk.

Good luck,

 

[boling]

Re: 1987 50 hp rough idle

Thanks for the help, will order the kits.

The tilt/trim leaks down also. is there a rebuild kit for the check valve?

Chris

 

[boling]

Re: 1987 50 hp rough idle

I started the with the carb kit, but have yet to find the needle valve for the slow speed adjustment. all the pics in the manual show one but I don't see it on these.

Numbers on the carb: 02245

On a Alum. plate glued to the bowl:
398076
M X
22 H L


Help!

 

[Dennisanoka]

Re: 1987 50 hp rough idle

Are you sure you have the right manual? I do not believe it has an adjustable idle screw. It should only have a idle orifice on the upper right-hand corner of the face of the carb body. That is for air only and needs to be cleaned out as well. Use an appropriate size wire to clean out every orifice and port in the carb. Did you get the core plug in the kit? Look for your engine @ http://www.evinrude.com/en-US/Accessories/Literature/Engine.Diagrams.htm

 

[boling]

Re: 1987 50 hp rough idle

The manual I have must not cover this carb. I have done the wire, carb cleaner and compressed air in each hole, replaced the float, needle valve and several gaskets.

There are some core plugs in the kit, but I've never put in a new core plug. There is one such plug on the top of the carb, should I remove and replace it with the new one? Does it require a special tool?

Sorry for all the dumb questions.

Thanks for the help.

Chris

 

[Dennisanoka]

Re: 1987 50 hp rough idle

Ain't no dumb questions, only the ones that don' get asked. Since you have one from the kit you can see what they are. To remove it take a pointed punch and stab a hole in the center then use the punch to lift it out. Not a big deal once you do it. You'll want to sure it is clean inside and any orifices clean as well. To replace it. put it squarely back in place then I tap it back into position using a socket extension. Not too hard so you dent it.

 

[boling]

Re: 1987 50 hp rough idle

Thanks for the help. I got everything back cleaned and back together, but I have the same basic problem on idle. with the warm-up throttle lever raised, she runs fine, once lowered, she eventually dies. It was late last night when we fired it up so I could do little checking. Whatever this is, I ain't found it yet.

Next steps?

Since there's no adjustment on the carb, where would I find the idle adjustment?


Thanks


Chris

 

[Dennisanoka]

Re: 1987 50 hp rough idle

First of all let me clarify a statement I made earlier. There is an idle adjustment, but it's just not part of the carb. With the engine off, take the cover off, raise and lower the throttle warm up lever. What you will see is that it is simply advancing your timing. When you lower the lever it will come to rest on a screw or close to a screw, that is your idle adjustment. Go to the link that I gave you earlier and go to the cylinder and crankcase view. Look at part#/screw #51. That is the adjustment for your idle.

I hope that does it for you. You should be looking for a smooth idle at 700-800rpm.

 

[boling]

Re: 1987 50 hp rough idle

I see it, thought that's what it was. Tomorrow I'll fire it up, try the adjustment.

I'll let you know.


Thanks for the help!

 

[boling]

Re: 1987 50 hp rough idle

While adjusting, I noticed the lower carb was missing the top core plug (must not have drove it in there tight enough). After some choice words, I got another put in correctly (amazing how thigs work if done correctly)

All seems fine now pending a trial out on the lake.

Thanks again for the help!

 

[boling]

Re: 1987 50 hp rough idle

Lake test went well, takes right off, gets up to about 31 or so (GPS), However, once the engine got warm, It don't want to idle in gear. I turned screw #51 in all the way with no improvement. One thing I noticed, there's no rubber boot where the threads touch the stop like my 40 hp does. There is another 1/2 inch of before contact with the carb linkage, guess I could try to find a longer bolt.

The diagram shows no boot unless that is what #53 is.

Suggestions?

Thanks again for the help

 

[Dennisanoka]

Re: 1987 50 hp rough idle

So when you are turning in the screw is it touching the timing advance? The screw is not opening the carbs, only increasing the timing advance.

 

[boling]

Re: 1987 50 hp rough idle

That is correct, it would take a longer screw to open the carbs. I think I could get a good idle before that happens. The fast idle lever moves the same assembly and gives me a smooth idle before opening the carbs. leaving me a space between the stop and the fully extended screw of about 1/4 in.

Chris.

 

[boling]

Re: 1987 50 hp rough idle

Now it will idle fast, but once put in gear, it will eventually die. Seems to get worse as the engine warms up. I told the owner to put in new plugs gapped correctly.

Not sure what else to try or look at.

Other than idling in gear,engine runs fine through WOT.


Thanks for the help.

Also,does anyone know where the fill plug for the trim/tilt fluid is on this model?