Power pack symptoms?

[dennisknight]

Okay, here’s one for all you fixer people. I have a Evinrude 35hp 1983 rope start. Ran great until recently, now will only run at idle both in gear and out of gear. Starts on first pull all the time, good spark to both cylinders. Checked and swaped new plugs and wires. CD2 replaced and carb rebuilt both less than 2 years ago. Will run on bottom cylinder only, but top cylinder does add to rpms, sounds like it anyway. Compresion is 130psi in both cylinders. Did all Clymer checks on ohm readings on coils. All check out OK. Pulled intake manifold, reed block looks brand new, no sign of burning, warpage, etc. Appears to operate fine when rope is pulled. Both plugs appear wet, although the top (trouble cylinder) is probably wetter than the bottom. New gas in tank, No arcing to ground when run in low light. What could be the problem? My questions are: If you get good spark (arc at least ½ inch and strong blue color) from both cylinders can the CD2 still be bad? I've replace two of them in 18 years and I seem to remember that when they went bad, I didn't get spark to one or both of the cylinders. Can the pack throw off timing to one cylinder? If I had a fuel pump or carb problem wouldn’t it show up equally in both cylinders? Any and all help, suggestions, ideas, ect would certainly be appreciated.

 

[Waterbugtoo]

Re: Power pack symptoms?

What exactly does it do when you throttle down on it? Does it run solely on one cylinder, or do you hear the other try to pick up firing intermittantly?<br /><br />

 

[dennisknight]

Re: Power pack symptoms?

I can pull the top plug wire and it will run at idle on only the bottom. When I reconnect the top it seems to pick up rpms or at least sounds like it. I won't run if I pull the bottom wire.

 

[Waterbugtoo]

Re: Power pack symptoms?

Thats not what I asked. What does it do when you advance throttle on it? Does it cut out and sputter or act like a solid dead cylinder still running on just one?

 

[rickdb1boat]

Re: Power pack symptoms?

Swap coils and see what happens. See if it will then run on the top cylinder only. If so, you found your problem. Ohmmeter reading do not always reflect actual running condition.

 

[dennisknight]

Re: Power pack symptoms?

If I open it up when out on the water, it will sputter and then die. Have to cut back on throttle to keep it running, but still doesn't "feel like" I'm hitting on both consistently.

 

[Capt Ken]

Re: Power pack symptoms?

Doesn't the fuel pump drive off the intake of #1 cylinder? Check to be sure the pump's diaphram isn't leaking fuel into #1's intake and flooding the cylinder. Also could be causing fuel starvation on #2.

 

[dennisknight]

Re: Power pack symptoms?

Yes, the fuel pump drive off both cylinders according to the manual. I'll check diaphragm tonight. If it looks good, I'll swap coils and see what that buys me. Is the top cylinder #1?

 

[kenimpzoom]

Re: Power pack symptoms?

Try these, they may give an indication of spark quality while running. Or hook up timing light.<br /><br />Spark plug boots that have a little light in them that flashes when they plug sparks.<br /><br />If you have random spark problems, these could be very helpful, and cheap too.<br /><br />Ken<br /><br /> http://www.jcwhitney.com/product.jhtml;$sessionid$WJ3D0FQAADHJCQSNDV1CFE0CJUOXKIV0?CATID=60764&_requestid=167867

 

[dennisknight]

Re: Power pack symptoms?

I've used a spark plug tester that glows and flashes already. Spark in both cylinders seems fine and both will arc to ground very strongly.

 

[snapperbait]

Re: Power pack symptoms?

One thought... Have you removed the flywheel and checked the charge coil and the sensor coil on the armature plate?.. Look at their wires for damage... <br /><br /> Pay particular attention to the sensor coil and make sure the epoxy potting inside the sensor coil has not melted...

 

[dennisknight]

Re: Power pack symptoms?

I suppose they're possibilities, and no, I haven't pulled the flywheel yet. Wouldn't both cylinders by affected if one or both of these coils were bad?

 

[Waterbugtoo]

Re: Power pack symptoms?

Before you go taking half the motor apart, put a timing light on top cylinder and throttle it. Does the fire quit when it sputters? Using a timing light, if both cylinders fire above idle, then its not the ignition.<br /><br />

 

[kenimpzoom]

Re: Power pack symptoms?

Would a timing light indicate a weak spark? I think a timing light would fire if there was enough juice to jump accross the gap, but that might not be a hot enough spark to make the motor run correctly.<br /><br />Ken

 

[Joe Reeves]

Re: Power pack symptoms?

DK.... You have described a engine that has a clogged/fouled carburetor. The description of the problem would lead me to suspect a clogged high speed jet that is located in the center portion of the float chamber. If so, the cure would be to remove, clean, and rebuilt the carburetorc. The fact that it was rebuilt two (2) years ago really means nothing as the carb would clog again if the engine sat w/o running for a couple months or so.<br /><br />The proper method of adjusting the carb after rebuilding would be:<br /><br />(Carburetor Adjustment - Single S/S Adjustable Needle Valve)<br /><br />Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.<br /><br />Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out, drop rpms, or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting. <br /><br />When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

 

[dennisknight]

Re: Power pack symptoms?

Well, I decided to take Joe's advice first and pulled the carb tonight. It was pretty clean although there was some sediment in the bottom maybe blocking what they call the orifice plug that looks like it feeds the high speed jet. Couldn't get the orifice plug out so I ran I .06" drill through it to open it up. What is the plug for anyway? Limit top RPM? What should be the hole size? Anyway, thanks for your input. I'll reassemble and try it out tomorrow if I get some time.

 

[Joe Reeves]

Re: Power pack symptoms?

DK..... That orifice plug "IS" the high speed jet. You would have been better off to use a solid piece of wire to simply clean it out as the size is critical. The proper ID of ther orifice depends on the engine model as follows:<br /><br />35RCTS - 35BACTS - 35TECTS w/aluminum bowl = 59D (.059)- - w/plastic bowl = 62 (.062)<br /><br />35RCTC - 35BACTC - 35TECTC w/aluminum bowl = 65D (.065) - - w/plastic bowl = 67 (.067)<br /><br />Anything under those sizes, the engine runs too lean. Over those sizes, the engine runs too rich.

 

[dennisknight]

Re: Power pack symptoms?

Joe,<br />I thought the vertical pipe leading up to the throat was the jet. I'm still learning. Anyway the 1/16 drill might just be right. I have a 35RLCTS which you didn't list. Maybe I should order the jet and new bowl to have on hand for future problems.....Thanks, I'll let you know what happens with the set up as is.

 

[dennisknight]

Re: Power pack symptoms?

Joe,<br />Just another observation. That orifice plug (jet) is really prone to blockage the way it's designed. It's right near where any sediment would settle. Seems like any sediment at all would be sucked right into it since there's no depression in the bottom of the bowl to collect any small pieces of solids. It just doesn't look like it would take much to clog it up. Is that the way it appears to you or am I missing something else?

 

[Hooty]

Re: Power pack symptoms?

A good inline fuel filter will stop the sediment problem.<br /><br />c/6<br /><br />Hooty