HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

[turtle1173]

Hello all,<br /><br /> I beg you for your assistance please. This is a 1976 55HP Chrysler outboard model# 559HG. Remember this has 1 Carb on it.<br /><br />Here is the scoop!<br /><br />My bottom cylinder seems to have excessive fuel in it, to the point of fouling out the plug. It will start missing (even at high speed) and then when I stop it will not hit on that cylinder anymore, until I change the spark plug. If I take the old plug out, clean it off, and try it, it still will not hit on two cyl. But a new plug will do the trick. The plug is always soaked. Now, if I go out the next day, the old plug usually works! I should also point out that the top plug looks great and gives me no problems.<br /> <br /> Here's what I've checked: My compression is 165 (top cyl) and 163 (bottom). My mechanic suggested that I swap the coils to see if that would switch the problem to the top cylinder, indicating a bad coil. That didn't work, the bottom one remained the same. My mechanic then suggested checking the reed assembly. I did that and there was one reed (that went to the bottom cyl) that you could see a little daylight when you held it up to the light. My mechanic said that it wasn't near significant enough to be making my motor do what it is. He then suggested that I check the spark (I had new points and condensors installed last month). The spark checked out fine. Just as strong on the bottom as on the top.<br /> <br /> So, I was reading my manual the other day and came across the cylinder drain system. The manual said that if the hose or one-way check valve was clogged or faulty, it would keep excessive fuel in the cyl. which would foul the plugs. It also said that the condition would continue to get worse (which mine is).<br /> <br /> I'm kind've at my wits end. I don't know what else to do. I really don't know what I'm looking for with the cylinder drain system. I just got the gasket off of it and was looking at it. Is there a way to check and see if it is good or not? Does this sound like a possibility? If not, what else could it be?<br /> <br /> Sorry for the long post but I sure would appreciate any insight into this.<br /> <br />Thank you so much,<br /> <br />Shane

 

[turtle1173]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

Hi again,<br /><br /> I haven't heard from anyone yet (hope I do soon). Another mechanic (online) has told me that he thinks it is a hole in the Fuel pump allowing fuel into the bottom cylinder. Does that sound like a possibility?<br /><br />Hope to hear from you soon.<br /><br />Shane

 

[steve12]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

I had the same identical motor for afew years. Not sure if this would be related but I will say that I had to constantly take carb apart and clean the needle valve seats on the float or change them. This continually gummed up and caused the pin to hang the float would just wobble around. The symtom was a lack of top end speed. Once I cleaned it good the little motor screamed.

 

[scotiany]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

How did you make out with your problem? Did you figure out how to check the puddle valves? When my engine (1970 Chrysler 55) was new, The factory had left a piece of styrofoam in the puddle valve screen. After that was fixed , it ran like a champ.

 

[12Footer]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

I've been remiss in my normal routine of late, and just caught your post. You should be able to blow air thru the cylinder drain hose ,and one direction only of the check valve. Be sure to note which direction it in when installed ,as putting it in backwards will keep it from recirculating as it should.<br />The compression is great. But it sure sounds like water, not fuel on the plugs, as it stays fouled until replaced.<br />The exaust port plate gasket,or head gasket may be letting water into the jug..Best to order a new set,and remove/inspect/re-torque the plate and head..Look for a spot where the original gasket did not stick,or corrosion path goes from one side to the other. Make sure there is no warpage or old gasket material on the surfaces, and resurface if needed.<br />This may sound kinda retentive, but it's actually quite common on Crysler/Force engines.<br />I don't have the manual to your motor, but check that your plugs are indeed, the recommended plug,and not a cross-referenced plug.<br /><br />But it sure sounds like water injestion. So, also check the entire fuel system,tank-to-carb bowl, for water contamination...Not as crazy as it sounds.

 

[turtle1173]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

Here is an update to my Above problem. I would appreciate any more help on this that you might be able to offer.<br /><br /> The puddle drain seemed to be fine, so I replaced the gasket and that was it.<br /><br /> I took off the fuel pump and it was just about petrafied. It had several hairline cracks in it. After I replaced this, it ran so much better and the top end speed was greatly increased.<br /><br /> Ok, here's my problem now. Even after I did all this, the problem with the bottom cylinder is still present although reduced. Normally when I start my motor at the ramp, it is only hitting on one cylinder. After I put her in forward and begin increasing the throttle, it takes about 2 minutes before the bottom cylinder starts trying to kick in. Then it is another minute before it hits on both cylinders. After that it runs great the rest of the day. <br /><br /> I went out a few days ago after not being out for 6 weeks. I went through the normal routine except this time it would never fully hit on the bottom cylinder. At lower speeds it would try and try to hit on the 2nd cylinder but never would kick in. Why, all of a sudden, would the engine not do the usual and start running as normal? It is much cooler now than it was 6 weeks ago. Could that have something to do with it or it sitting much longer than usual without being run?<br /><br /> 12footer, I'm interested in hearing more about what you stated concerning water getting into the cylinder. Is there any tests or anything I can do aside from taking the head gasket off? I don't have a replacement and am not sure where to get one. Also, if there was a problem with water in the fuel or the carb, wouldn't I also have problems with the top cylinder?? This is a 1 carb engine.<br /><br /> Would putting some fuel into the cylinder prior to start up help in getting her going until she's able to start hitting on 2 cylinders? Obviously that would just be a temporary fix until I can get another head gasket.<br /><br />Everyone's help is very much appreciated.<br /><br />Thank you,<br /><br />Shane Williams

 

[steelespike]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

Usually if you are getting water in the cylinder<br />you will have a very clean plug.<br /> Have you checked the high speed jet size it is<br /> stamped on the jet and is visable when in position.Apparently critical regarding elevation.<br /> If you mess with the jets be aware too small<br />will cause a lean burn and possible engine damage.<br />I find 7 lists of jets based on carb model and elevation.<br />Choke adjustment appears pretty critical as well and it says be sure it measures .010 to .040 open<br />when engaged and solenoid plunger is bottomed,<br />and returns to full open position.If there are 2 carbs and they are the same model try swapping them around.<br />Point gap is critical and should be checked by manual procedure. .020.

 

[turtle1173]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

I took my boat out again today. I put 2 brand new plugs in before I left. It went through the usual problems with only hitting on one cylinder. The engine tried and tried to hit on the bottom cylinder. Finally it stopped trying about half way through the trip. When I got back to the ramp I pulled the plugs. The top one looked normal. The bottom one had soot caked on it.<br /><br /> I was looking a little more closely at the head this evening. The bottom two bolts are rusted. The two up from the bottom are partially rusted also. The head has never been pulled to my knowledge but I'm a little nervous about doing it. <br /><br /> What am I looking for if I do pull it? How much information can I tell about the engine from inspecting this way? Any help would be appreciate with this.<br /><br /> I haven't messed with the carb because it only has one carb. If there was a problem with it, wouldn't the top cylinder be messing up also??<br /><br />Thanks for your help.<br /><br />Shane

 

[Trevor]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

have you tried a T-stat maby it is running too cold I know that the yamys need towarm up properly or the same thing happens. it a simple thing but not a known thing. people spend too much time looking for a difficult solution and not a simple solution also how are your reed valves? another thing if you are running too much oil it will pool inthe bottom of the manifold after sitting for a while and then get slwoly sucked in as you run the motor. if you troll a lot then i would say change your t-stat. <br />good luck

 

[Trevor]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

also I forgot to mention that I would check the points again maby the tech did not set then=m properly had that one the motor will do whaT YOU ARE SAYING.

 

[ob]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

turtle, I'm thinking the cause of the problem has been eliminated and now you need to deal with the side effects.You say you changed the fuel pump and had a noticeable difference in top end performance.I'm thinking your original failed pump was flooding cylinder, while fouling plugs, and may have left considerable carbon deposits ,which is what you are describing on bottom plug after a short run.Your compression readings are pretty high as two strokes go and if rings are not stuck back in grooves excessive compresssion can be indicative of significant carbon and soot deposits.This alone can foul the plug.<br /> 2- Don't rule out the possibility of water intrusion into cylinder being culprit just because plug doesn't apperar unusually clean when removed.There is a point at which combustion is poor enough not to atomize water causing this clean plug condition.<br />Also with the described condition of head cover bolts that could very well be the culprit. In any case I would remove and service head cover as the condition of bolts securing it sound like a gasket failure in the making.

 

[scotiany]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

Found this in the past posts.Don't know if it applies here but, who knows. <br /><br /> <br /><br /> <br />Author Topic: Symptom of reed valve failure? <br />mikec<br />Member posted June 26, 2001 01:44 PM <br />--------------------------------------------------------------------------------<br />Anyone know what the symptom of reed valve failure is? I suppose this would be when a reed doesnt seal all the way. Would the failure be RPM sensitive? Can it be diagnosed without taking the carbs off?<br />IP: Logged<br /> <br />12Footer<br />Member posted June 26, 2001 06:20 PM <br />--------------------------------------------------------------------------------<br />Low compression is one symptom.<br />Spitting fuel from the carb,or air pressure fealt when hand-choking it.<br /><br />IP: Logged<br /> <br />ODDD1<br />Member posted June 26, 2001 07:50 PM <br />--------------------------------------------------------------------------------<br />A broken/ leaking reed in a multiple cylinder engine will cause that cylinder[with the bad reed] to act lazy.....depending on the size of the leak, the engine could run fine at WOT, but will always be lazy at idle/part throttle....a broken reed allows the intake charge being compressed in the crankcase to bleed away....so that particular cylinder will act lean...an extra shot of fuel down the bad cylinder will generally make it fire briefly.....an experienced tech can usually pick up a bad reed just by listening at the carbs when the motors idling...they make a distinctive sound...an engine with a bad reed will have the same compression in the cylinder as a good one would, unless the broken off piece caught in the piston/rings and damaged them....<br />IP: Logged<br /> <br />mikec<br />Member posted June 26, 2001 08:22 PM <br />--------------------------------------------------------------------------------<br />Thanks so much! Im chasing a low/mid RPM "miss fire/boggy cylnder" problem and will follow this avenue of troublshooting. Thanks again. -mikec<br />IP: Logged

 

[turtle1173]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

Thank you all for your help with this.<br /><br /> The reed valves are new. I replaced them before I found out about my fuel filter. The points and condensors are new also.<br /><br />OK, so where do I go from here? How do I get the carbon out of the bottom cylinder, if that's what the problem is? Decarbing won't work if I can't get it to hit on that cylinder will it??<br /><br />Will I be able to see excessive Carbon build up when I take the head off?<br /><br />OB,do you think the Thermostat might be a possible problem?<br /><br /> Here's another thought: My boat performed so much better right after I replaced the fuel pump. Why would it now be getting worse and worse if that fixed the problem? I guess perhaps the carbon is starting to come off the cylinder walls.<br /><br />Thanks,<br /><br />Shane

 

[ob]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

turtle, I'm guessing you are going to see a sigmificant amount of carbon when head is removed.Decarbonizing is a procedure that is maintenance effective when performed before an excessive amount has accumulated.You definately have one of those cases as you have the dilemma of not being able to run motor effectively enough to expel.<br /> Also as you mentioned above , the carbon is now sloughing off and gap bridge fouling plug.I'm also guessing that you'll find that cylinder is getting some water injestion when head cover is removed.Water will also cause carbon to slough off as it is sometimes used as a crude procedure in decarbonizing.<br /> I don't feel that the T/stat is a player in your particular problem,however it wouldn't hurt to install a new one.

 

[turtle1173]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

I'm going to remove the head tomorrow and check out the condition of the cylinders. I've already got a new head gasket on its way. I do have a few more questions however.<br /><br />1) What will carbon look like? I guess that probably sounds dumb but will it just be black all over the cylinder walls? What constitutes a "significant" amount?<br /><br />2) How do I get the carbon out? What product or procedure do I use?<br /><br />3) How will I be able to tell if water has gotten in the bottom cylinder?<br /><br />4) While I've got the head off, is there anything else I should check out? I don't believe the head has been off the motor before.<br /><br /> Thank you so much everyone for your help. But I'm just getting started <br /><br />Shane

 

[ebbtide176]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

just wanted to mention that you might try regular spark plugs vs. the "surface gap" type that you might be running now. it is supposed to be related to the amt of usage in idle vs high speed operation. in other words, are you running at strong speeds on average, or idling? i would guess the others know your motor better than i. but my 70hp 1970 chrylser didn't do well with the 'surface gap' style plugs... (the ones with no bar on top)<br />so you might want to experiment(according to seloc manual) with the surfacegapped UL18V, or the regular style L4J at .030... mine really liked the NGK BR7HS plugs

 

[12Footer]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

1).Carbon becomes a problem when it is thick enough to cause rings to expand or stick in the lands, when it plugs the exaust ports, or fouls plugs.<br /><br />2).It will manifest itself as a black cake, or tar like buildup.<br />You may have to physicaly scrape it out of the ports and head. Most decarbon treatments work as directed. But I've found my Force runs lousy with the fuel additive types, so I use the spray can type, and use it often. These engines build carbon quickly.<br />3). Water in the cylinder will show up as a spotlessly clean plug. It may be wet, or have surface rust on it.But mainly it will appear new.y plug that has run an outboard for an hour os so, will have a dry black or brown appearance around the anode<br />4). Yes. order the exuat port plate gaskets too, and remove/clean/re assemble. They're fairly cheap,and this is where the chrysler/force engines like to put thier excess carbon,in exaust,salt crystals in coolant channels.<br />Personally, I would stick with reccomended plugs. At least, make dang sure the heat range is identical before switching. The surface gapped plugs are finicky, but hold up fairly well. If they aren't giving suficiant spark, then you have a HV problem causing it. These plugs are used on engines with very high spark voltages,capable of jumping an open-air gap of 1/2inch! They sting like a bee if you get too close.<br />be carefull with the head bolts>they often become part of the block over years> use plenty of rust buster> and let it soak>ntly tap the head bolts<and let them soak some more< even if it takes a week to get them out in one piece< it"s worth the extra effort>

 

[turtle1173]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

OK, here's the latest:<br /><br /> I removed the head this afternoon. I smothered it with Marvel mystery oil lubricant. Let it set for an hour and then removed all the bolts. It wasn't that difficult but I took my time. The head gasket came off in one piece.<br /><br />OK, here's what I found. The cylinders are amazingly clean. The top of the pistons have a very very small amount of carbon on it (nothing uniform, just here and there). The cylinders look nice and smooth. I couldn't see anything to lead me to believe that water is getting into the cylinder. What would it look like if there was?<br /><br /> I inspected the inside of the head (the part that I took off, where the plugs screw in). The bottom cylinder looks brand new. The top one is covered in oil.<br /><br /> I took a flashlight and peaked into the holes that go to the exhaust port. The holes are not plugged by any means but I can see quite a bit of carbon pieces built up in there.<br /><br /> My main question is: How would you interpret my findings? Is my next step to take apart the exhaust port plate? Could the carbon build up in the exhaust plate be my problem?<br /><br /> You all are great and I sure appreciate your help. What a wonderful forum!! Please continue to help me through this.<br /><br />Thank you,<br /><br />Shane Williams

 

[ob]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

The bottom cylinder of head cover looking clean and new as compared to the top I feel is indicative of water injestion.The leak source is either the head cover gasket or exhaust cover gasket.

 

[turtle1173]

Re: HELP!! 55HP Chrysler 1976 - Missing, fouled plug problem

I guess this shows my ignorance but I didn't know that the water circulated in the exhaust port. So I suppose that this is my next step: Take off the exhaust plate.<br /><br />The head gasket looked to be in good shape. I didn't notice any deformities or discoloration in certain areas.<br /><br /> So it may very well be the exhaust port. I can definitely see carbon build up from looking through the top and bottom cylinders into the exhaust port.<br /><br />Shane