fogged nieghborhood

some may have read about my '62 28 sea horse that does not seem to be revving out to proper rpm at wide open.I am still trying to get my hands on a tach,or even compression guage to further the quest.in the meantime I remembered the guy I bought it from saying the boat had been passed around between his family and ended up with his son who said it wasent running out like it should.this got me thinking,and after searching alot here,I bought a can of sea foam.after using all of it,the motor is still pumping massive smoke! I am currently waiting for a little I had left from another can I bought for my jeep to do it's thing - onto the question....if this motor had 45 years of carbon bult up,is it possible It had a reed stuck open, stuck rings,etc. that this de carb would fix ?

Re: fogged nieghborhood

See my thread about my 71 Johnson 9.5 HP not revving out. You need to check it all out. It's time for the exploraratory. I've already replaced points, plugs, condensors, rebuilt the carbs, and have sprayed Sea Foam 5 times now and the last time it still smoked a lot, although less than the subsequent cleanings. I just bought two new coils today because I think it's likely that's the problem, per iwombat's suggestion as well. In my case, I've got yellowish to yellow sparks on my plugs, and I'm going to do a spark test tomorrow to see how far the sparks jump before installing the new coils. Then check the new coils with a spark test just for confirmation. I'll replace plug wires if I need to, but have confirmed sparks are not jumping from my plug wires, and they do look good.

My compression is only 68 psi on both cylinders, but they say don't worry about that since I'm starting and idling good. But I'm not done with the Sea Foam and it may free up my rings once the thing quits smoking. I'm gonna let a puddle of it sit in the cylinders tonight then blow it all out tomorrow before starting it. I've had a time trying to find the problem, but there's not much left that could be wrong. And I certainly don't like yellow sparks.

If the reeds are stuck, that would show up in the compression readouts (I think), since they're not closing, thus pushing gas/air back out the throat of the carb rather than sealing up good. The way to check that is to take a business card while it's running and hold it in front of the carb throat. If you have a mist of gas on the carb, the reeds are okay. If you have a lot of gas, they're not. Come to think of it, that's one blasted thing I didn't check on my motor! I did take a visual of the reeds when I rebuilt my carb, but didn't remove them and look closer for broken edges, and foreign objects holding them away from the reed stops. They say if damaged the whole read valve assembly (one for each cylinder) has to be replaced. Looks like my manual says that the leafs should barely seat against the stops for a 1971 9.5 HP, and be centered on the alignment marks of the reed housing. On newer, circa 1986 motors, I've read there should be .010 of clearance, which closes completely to prevent gas/air mix from escaping the cylinder on the piston downstroke.

One other thing - is your prop okay? What is the diameter and pitch? If it's damaged or too big, that's one thing that keep it from turning adequate rpms. On my motor I'm turning an 8 1/8 x 8 pitch, which could be a tad big given lower compression and an older motor. I think that was the size of the prop it came with new, so it's possible it could have a harder time 36 years later. But I'm not done tuning my motor, so we'll see.

Re: fogged nieghborhood

Stuck reeds wouldn't show up on the compression test. That only measures how the piston compresses air past the intake and exhaust ports. Carbon won't stick the reeds open anyway. Carbon builds up in the combustion chambers, not in the crankcase and intake.

Re: fogged nieghborhood

I have done new coils,condensors,points,carb and fuel pump rebuild,etc-tossed a bunch of cash at it.the prop I suspect too.I do know this is an aftermarket prop from the '60's and while lower in pitch even the company who made it says I should try OEM-I'm waiting on getting a tach on it before changing it though-an interesting thing I noticed when I ran the motor the last time-it sounded as if one cyl wasent firing at mid throttle and would then kick in for a sec-everytime it did so,it would create a little puff of smoke-

Re: fogged nieghborhood

You need to warm that engine up and then remove those plugs and soak each cylinder with sea-foam squirted in the piston holes themselves and let it soak for at least an hour.
This will soften the carbon and let it blow out or burn off. What type of plugs are you running in this motor.

Re: fogged nieghborhood

I did do that last night.I'm running champion J6C.the cutting out thing at mid throttle gives me more to go on. although I didnt notice it before,I am begining to think I have something shorting out as the armature plate turns-it definatly FEELS like it's running on one at top end but it sounded like it was running well to my un -trained to outboards ears.I will check spark as someone moves the throttle lever to see what happens.

Re: fogged nieghborhood

I ended up having a problem with plug wires on mine. On another thread, iwomboat had suggested plug wires for someone having trouble with a motor that was cutting in and out like that. You can check plug wires with ohm meter and try wiggling them around and making sure you have good connection and see if the reistance ever drops out. That was the case on my motor.