67 5hp evinrude outbaord

I am doing a complete rebuild and when i took the manifold off the motor yesterday there was a problem. the entire inisde of the manifold is caked in black stuff (carbon?. Does this mean i am running rich and if so ow do i solve the problem? It has a needle valve at the top of the carboreator but the writing is worn off. what is this needle valve for (asuming its for flow control) The needle is good but dont know what its supposed to be adjusted to and when to adjust it.<br /><br />Help

Re: 67 5hp evinrude outbaord

Oh, that's not good at all. It indicates there's been ignition in the crankcase. Go ahead and pull the reed plate out and see if it's isolated to one chamber.<br />This may have been caused by running lean or (I suspect) heavily coked piston rings. How's the compression on your engine?<br />Lean running in one cylinder may have been caused by a crankcase seal leak. If it's been run like that a long time, there may be bearing damage.<br />Are the reeds themselves badly distorted?

Re: 67 5hp evinrude outbaord

The black stuff has an oily consistency. where would the reed plate be located. I have removed the entire motor and can see the exhaust hole in the cylinders. I turned the flywheel an it runs smoothly. I watched the pistons go by and didnt see any damage. Having trouble getting the cover to the exhaust plate off. I found out what that needle was for, its fot controling as to wether it runs rich or lean and i have been running it wide open. Have pulled the head and inspected it. It has a little bit of the black stuff on it. When i cleaned the piston head i saw no damage. could it be there because i am running way too rich. I have no means of compression testing. Where would i find the reeds, and please dont tell me they are behind the exhaust plate.<br /><br />Thanks

Re: 67 5hp evinrude outbaord

Don't remove the exhaust cover unless you have to - all those bolts are going to be rusty and wanting to break. If you do remove them, be very gentle and use lots of heat and penetrating oil. Above all, patience.<br /><br />I think I misunderstood about the black stuff - I thought it was dry and powdery. Since it's not then it may be gunk dripped down from the combustion chamber if some oil was put in there to winterize it or excess fuel/oil mix from running rich, and the engine was left carb facing down.<br /><br />The reeds are just behind the intake manifold - you may have not noticed them. They're little one way air valves. If you have them off, you can see straight into the crankcase.<br /><br />I hope I didn't get you too worried!

Re: 67 5hp evinrude outbaord

i have a stuppid question for you, where is the intake manifold. not used to working on 2 cycles or anything involving a boat. Right now i have the entire engine detached from everything. I have the entire block sitting on my bench. The motor had alot of lower unit problems like water pupm and gear casing replaced all of the seals and its has stayed water free. I am now trying to work out any and all problems before trying to put the motor back in the water again. Do you know if this motor has a thermostat? is this motor supposed to have oil in the crank case. When i turn the flywheel it cycles smoothly. <br /><br />full of questions

Re: 67 5hp evinrude outbaord

The intake manifold is the bit that the carb bolts to. Underneath it are the reed valves that control fuel/air flow into the crankcase.<br />2 strokes don't have oil in the crankcase, except for the oil that's mixed with the fuel, they don't have a sump like 4 strokes do.

Re: 67 5hp evinrude outbaord

I think you really, really need a Service Manual, ET.

Re: 67 5hp evinrude outbaord

went out and got the service mauel as suggested and did some reading. I understand 2 cycles now. I know where the reed valve is, but what i dont understand is that the carb in the breakdown diagram has a high and low speed adjustment needle for my model, but on my motors carb it only has 1 adjustment needle. Is this normal? if so how do i adjust it to get max rpm on WOT? Trying to return engine to a efficient working state. I have replaced the head gasket and all seals and impeller in the lower unit, and its water tight. looks like new fuel pump. Had a problem with water circulation but brushed out all areas where water is supposed to be. Manuel also shows there is a thermostat. Took off the plate thats supposed to be over the thermostat and there was nothing inside. If i am missing a thermostat will that affect the water flow around the cyclinders? I have assumed by the condition of the motor that it has never been serviced. Any suggestions as to what else might need to be replaced as routine maintenance? Have not looked at the points?<br /><br />slighlty more educated on 2 strokes

Re: 67 5hp evinrude outbaord

Not a problem, if you only have one needle that is the low speed adjustment, instead of a high speed adjustment needle you have a fixed high speed orifice.<br />There should be a plug covering the orifice in the same place as the needle would be, if you remove the plug the orifice can be unscrewed and inspected.<br />If there's a thermostat housing but no thermostat, it's probably been removed as defective and not replaced. Just as in a car this means the engine will be slower to warm up and will run cooler at lower speeds, possibly causing idling/low speed troubles.<br />Do you have the flywheel off? What are the coils like, cracked cases or intact? For the very small cost involved I'd replace them anyway, and the points, condensors, HT leads, boots, and sparkplugs.

Re: 67 5hp evinrude outbaord

the entire electrical system is new the points are gapped correctly and arent burnt. Tried to take the exhaust cover off (big mistake) and cracked it. any suggestions for a quick fix or sould i try and hunt one down. I dont know if the part is NLA ( i hope to go not). The reeds look fine theyb arent bent or broken. Only problem now is getting the damn studs out from the exhaust cover and getting a new exhaust cover. In the evnt that there is not quick fix for the exhaust cover and it is NLA is there somebody that sells after market parts that you could recomend?<br /><br />Pryaing its not NLA