Logo
FULL SITE MENU

Metal shavings

J

jvmvjv2

New member
I have a 1976 70hp johnson sea horse. Its been giving me problems staying on when shifting into forward. Ive been working on the carbs and and other fuel related issues. The problem Im having now is...I was working on adjusting the carbs and I had the boat out of water with the muffs and garden hose running. All of a sudden the motor started running rough and started smoking out of the exhaust coming from the center of the propellar. I shut if down and saw gear oil coming out behind the propellar. I removed the propellar and bearing housing assembly and found the gear oil had very small metal shavings. My question is what should I be looking for to see where the shavings came from? Also does this mean the lower unit is no longer good?
 
The metal shavings should be fine with no chunks. This is normal. Chunks means things are broken. I bet it is not gear oil leaking from the prop, but is engine oil leaking through the exhaust as it builds up in the exhaust.
 
Hi Hondamech. Yes it seems like you are right. I looks like its coming from the exhaust and building in the exhaust and yes it has small shavings no chuncks. When I took the plug out of the lower unit to check the gear oil and it was clean. I had just replaced it a month ago. Now I have a question. This is a 2 cycle motor and I have to mix a 50:1 fuel/oil mixture. I was not aware that this motor had a separate oil pan somewhere. Am I correct to assume it has a separate pan? If not then where is the oil coming from? Please explain it for me. Thanks in advance.
 
It does not have an " oil pan " for the motor.---------The nature of a 2 stroke motor is that some gas and oil goes thruogh the motor while both the intake and exhaust ports are open.---This gas and oil is wasted !--------It shows up in the exhaust housing and drains down to exit at the prop.------Still do not understand , then visit You-tube and learn how a two stroke engine operates.
 
the ''rough'' running is the reason you are seeing the oil in the exhaust....fix that and you will be ok...i would do a quick compression check if you havent already done it....then check the fire and make sure you have a spark that will jump 7/16 of an inch....if both are good then proceed with the carb work...final adjustment on the carbs should be done with the boat in the water....on that motor the varnish or whatever they put on the coils will crack and allow moisture in...make sure you are not running on two cylinders instead of three....
 
Thanks RACERONE and PAPYSON for the info. Papyson I already checked the spark and it jumps the 7/16 gap with a stong spark, also pulled one wire at a time while it is running and it misses so yes they are all firing. Compression is good too. #1-130 #2- 128 #3-130 and I purchased and installed the rebuilt kit for the carbs. And yes motor still runs rough. I syncd the carbs but I want to check timming. Can you explain the procedure to ck and adjust timing? Thanks in advanced.
 
The only ways timing goes out of adjustment is when someone fools with it , or when the flywheel key shears due to improper torque of the flywheel nut.--------Have you checked the reed valves ?----Were the high speed jets removed from the bottom of the float bowls for cleaning ??------These jets are about 5/8" long and it is a step that is often overlooked.--Have you checked for a ruptured diaphragm in the fuel pump? That will dump raw gas into the motor and cause lots of smoke and oil at the prop.
 
I purchased this motor in November from a friend and he purchased it as a spare for himself so I dont know the history as far as the flywheel being removed. I just wanted to rule that out. I know the jets you are talking about. I did not remove them for cleaning because they seemed to be jammed in place. I couldn't figure how to remove them and I didn't want to damage them so instead I soaked the carb in cleaner for a day and proceeded to reassemble. I can remove the carbs again thats not a big problem. Can you explain how to remove the jets? Oh and I replaced the fuel pump with a new one before I took it out this season. Thanks again for your time to help me out RACERONE. The weather hasnt been the greatest for a couple of week and now it is nice outside and I really want to go fishing! I hope with your help I can get it going.
 
In most cases the jets can be removed with a 3/16" diameter screwdriver.---------So I do not see that you have confirmed that the flywheel key is good ( it controls timing ) on this motor !-----Have you confirmed the condition of the reed valves ????---------Answering questions very clearly can lead you to the smoking gun.-For some unexplained reason folks seem reluctant to answer questions.
 
Im sorry about that. I thought I answered that question. Yes I looked at the reed valves when I had the carbs out the first time and they looked good. Didnt see anything out of the ordinary. Im about to take the carbs out again and try to remove the jets. I will also remove the flywheel to look at the key. I will post what I find.
 
Ok. I removed the carbs and like I mentioned before the jets wont come loose. Im using the screwdriver and the ends are starting to bend. I also rmoved the flywheel and the key looks fine.
 
Back
Top