Symptoms of reed failure ?

[stsmith]

Before I start pulling my engine apart. Could someone please tell me the symptoms an engine would have if the reeds were broken, bent, stuck, dirty or any type of reed failure?<br /><br />Thank you Smitty

 

[OBJ]

Re: Symptoms of reed failure ?

Sure Smitty......one big symptom of broken, cracked or missing reed is blow back through the carb.....usually really prevalent at low rpm. Put your hand in front of the carb at low idle and see if it comes back wet with fuel. If it does, you have a bad reed there.<br /><br />Another symptom is really lousy idle and no matter what ya' do, it don't get better.<br /><br />You didn't post the hp or year of your engine so I couldn't say for sure if removing the carbs will get you a look at the reeds. Most engines it will.

 

[stsmith]

Re: Symptoms of reed failure ?

Sorry about that. It is a 1978 Johnson 55hp 2cyl.<br /><br />But I've the carbs off and could not see the reeds enough to see if one was broken.<br /><br />Thanks Smitty

 

[P.V.]

Re: Symptoms of reed failure ?

One thing to mention, if I may, is... most of us have "heard" of problems "associated" with a broken reed, when, in fact, a defective/broken reed is a fairly remote and rare occurance!! It happens and when stump'd, we go .. "Well, maybe it's the reeds!", but again, it almost never happens! Symptom would be, down on power, the engine loses it's ability to suck and hold the air/fuel inside the crankcase. The mixture would just enter and expell from the "hole" (caused by the open reed port) and so the fuel never gets into the cylinder to be burn'd, hense, efectivly, a "dead" cylinder. Visually you may see fuel and air being pushed out of the carb but also, a "cylinder drop test" will show no response to removing the spark plug wire from the offending cylinder when running. Don'<br />t confuse other problems/causes affecting how the motor runs with a reed problem! Broken reeds are most often caused by over-reving the engine!! I've personaly seen only a very small number (4 or 5) engines that have suck'd a reed in the (what seems to be a long career) years I've spent doing this! It can happen, but it's just not as commen as you may think!

 

[Walker]

Re: Symptoms of reed failure ?

Also the intake manifold, including reed cages, is pretty easy to pull on that motor. You should be able to see a broken reed without pulling the manifold though.<br /><br />Could you tell us whats going on with your motor? Symptoms???

 

[stsmith]

Re: Symptoms of reed failure ?

55EL78S<br />poor idle, no power, major fuel consumption. New fuel pump, compression (w/new gauge) 140/145. rebuilt carbs. Runs like a bat out of hell on seafoam mix. but badly on reg fuel. Did the spark plug wire pull test. pull wire engine almost dies. both cyl. Appears to have good spark at plugs. Did a resentance test on every thing book says posible. <br /><br />My next test is to set the carb float level too low by specs and put in the bay and try again.<br /><br />Any help or suggestions greatly appreciated.<br /><br />Thanks Smitty

 

[Walker]

Re: Symptoms of reed failure ?

Runs like a bat out of hell on seafoam mix. but badly on reg fuel.

What sparkplugs and gap are you running and have you tried fresh fuel.

 

[stsmith]

Re: Symptoms of reed failure ?

Ql77JC4 gap .030 <br />Tried new fuel even new gas tanks.<br /><br />Thanks for the input.<br />Smitty

 

[Yepblaze]

Re: Symptoms of reed failure ?

Just in case:<br /><br />Sometimes it requires that the carb jets be carefully probed (to dislodge deposits) and viewed very closely (for clarity) when doing a carb overhaul. <br /><br />If by chance all that was done was soaking or spraying, go back and check em out.

 

[steviecops]

Re: Symptoms of reed failure ?

Did you replace all the fuel lines when you did the carbs? <br /><br />Maybe one of them is split and is leaking, major fuel consumption, and sucking in air, no power and lousy idle?<br /><br />Good luck<br />Steve

 

[rabidfish]

Re: Symptoms of reed failure ?

Since it runs on the seafoam mix, I would suggest that you are having problems "igniting" the charge. You probably do not have a good cylinder seal. Compression is not an accurate measurement on a 2 stroke outboard. The crankcase needs to be compressed by the down-stroke of the piston. Without this "compression" the engine will run like... you guessed it... like it has a bad reed. <br />Fit new pistons & rings & i'd bet my bottom dollar your engine runs like new.

 

[R.Johnson]

Re: Symptoms of reed failure ?

On a 55hp twin cylinder, I would quit wasting time and pull the head.

 

[stsmith]

Re: Symptoms of reed failure ?

I have pulled the head. Head gasket looked good, cylinder walls looked good with no major ridge at<br />the top of the bore, no major carbon build up. What else should I be looking for when I pull the head again?<br /><br />Smitty

 

[G DANE]

Re: Symptoms of reed failure ?

I'd put my money on a good carb clean, including soaking every metal part in carbs overnight, everything blown through with compressed air and floater hight set exactly at highest correct setting. That being said cylinder failure often happens on theese twin 55's. Seems like the loop ports were too big, giving the pistons poor support. If everything in both cylinders looked fine on yours, I wouldnt pull head again, just get carbs and ignition working. Did you try if both sparks could jump a 7/16 gap to ground ?