My motor has had cooling problems. I replaced thermostat and water pump. It runs cool now and does not get hot when it is at full throttle. My problems are:Can't put the cover on the motor or it will not idle.. seems like an air restriction of some sort.. I don't see any obvious way that a large volume of fresh air can get into the motor housing. So, I have run the motor without the cover on. It runs good but does not idle great. Also, the other day I took the boat out and it ran full open for more than 30 minutes. Didn't have a single problem with it until I came back near the dock when it sputtered and would not stay at idle. I found watter in the fuel filter and in the float. Cleaned all of that out and it ran great. I had the manged go get way too much watter in the engine compartment and it got sucked up into the carborator. Today I took the boat out hoping I had fixed things and it stopped running after 5 mintues. I was running full open and it just shut down. It would fire, but not idle consistently. The cover was off of the motor today too. I'm just lost on this now. I've fixed a lot on this boat, but this probelm is just beyond me. I've cleaned out the carborator, but not put anything in it like a re-build kit. Was thinking that it was possible that the carb get's empty at full throttle, but this is inconsistent with my experience the other day when I ran if full open for a long time without any problems. Also, I'm running 16:1 fuel/oil. I need a reliable engine as I have two small children who are with me when I boat. I feel like I can trust this old motor if I can get it going and maintain it well. Any obvious things I can do to avoid having to take this old motor to the shop?Thanks to everyone here for their contributions. This is a fantastic place to get information.Dean
Oh.. also, when the motor was running wide open today for that brief time, I could not help thinkign that it sounded like there was some "pinging" or a sound like a motor makes when it is low on fuel. Again, it was not running hot and no watter was on the engine. Thought this may be important info..
Oh crud.. reading another poste I think this may be important. I'm kida new to this boat repair stuff. The prime pump seems like it used to get hard, but it does not now. I have the vent to the tank open, but the ball just makes some "weezing" sounds. I can tell that gass is getting up into engine, but the ball does not get hard. Matter?
Engines that don't run well with the cowl on are often experiencing an exhaust leak. Sometimes a wire can be getting shorted out when the cover is placed on also. You should be running 50:1 87 octane unleaded/tcw-3 oil. I wouldn't keep running it without the cowl until it's fixed. Not much fun when someone falls on the flywheel.
Alden. Thanks for your reply. Actually, it does seem like there is a bit of smoke at the front of the motor just under the carborator. It's pretty hard to see in there to determine if it is exhaust. I guess it would be a pretty safe deduction now that I come to think of it. I'll look at the engine diagrams and see if that makes sense with the exhause idea.
Can you state again what your fuel to oil mix is? Either way 16:1 or 16 oz. oil per gallon of gas (8:1) is way too much oil. That motor would run on 50:1 or 2.56 oz. oil per gallon of gas. 16 oz. oil would be enough to treat six gallons of gas.
Calico is right on about the fuel mix. I'm a little burned out today after court with ex wife. One 16 oz bottle treats one six gallon tank, not one gallon. That would make as Calico said, a 50:1 fuel mix. Sorry Dean my mistake/mistype.
I put 48 oz in 5 gallons of gas. That is 9.6 oz per gallon, right? Motor does smoke, but not sure what is normal on this motor. Would something like this cause my motor to do a dead stop from full throttle? I guess I should check the condition of my new spark plugs to see how they are looking. Any thoughts based on this info?
I'd start with a fresh tank of gas with the proper premix Dean. The ball should get quite firm and stay that way while running. Once in a while I need to pump the cheap Attwood ball on my fishing boat excessively to get it firm. The OMC brand bulbs are much better. Check out the hose(s) all the way from tank to motor and the fittings for leaks.Try one thing at a time, new gas, new bulb if you need it and see how it runs, if there's still trouble get back to us OK? If it runs better let us know too!
Alden and Calico. Thanks for the info and advice. I noted that the fule:oil mixture is stamped on the engine housing next to the connectors.. and it says 100:1. This would mean that I have just flooded the engine with oil. Guess I'll need to fix that issue first and see if it makes the difference I'm looking for. If your info is correct (16oz of oil for 6 gallons gives you a 50:1), then I just need 8 oz per tank.
You still need 16 oz rather than 8 oz for a 6 gal. tank. Some motors in the early 80's were specified for 100:1 but that was later changed by an OMC service bulletin to 50:1, i.e. 1 pint TCW3 for a 6 gal. tank.
Don't run it at 3/4 throttle out of the water. If you keep it on a trailer just back it in but don't launch it making sure that you have backed it in far enough to get the water pump under the surface.
ok.. put the proper mixture in it (16 oz with 6 gallons) and it ran great (for an old motor). I even ran it with the cover on. I think the smoke from running too much oil threw off the fuel air mixture too much.. Anyway, it runs great.Had the motor down and boat dipped back and saw that some of the gear oil leaked out through the prop. Is any amount of this oil leaking a bad sign or is a small amt ok? I had hoped to just change the oil frequently and not deal with re-building the gear box. I've seen the gear assembly and it does not look like too much fun to take apart. Can I just take out the seal at the prop end of the assembly or do I have to tear it all down? If I can just take out the outer seal next to the prop, how do I get it out? Just pull it out or need a special tool?Thanks Guys.
I think your "gear oil" is unburnt 2 stroke oil , the main exhaust is in the middle of the prop and when you used it with too rich oil mixture the engine was not able tu burn that amount of oil and it leaked to the exhaust and now it is leaking out of the middle of prop.Check the gear oil level first and run it for a while then check the gear oil level again. There could be some oil coming in the middle of prop when runninq with proper mixture also.
I think you are correct. The oil that I saw leak out was black while the gear oil is "normal" color. I've been watching the gear oil closely to make sure I'm not having a water leak problem, and so far it looks good. My early contamination may have just been due to rain getting in while I had it apart. I flushed the gear box out with gas three times to and examined the waste to ensure that I did not see gear shavings.. so far so good.. Thanks for the help..
I have my boat running well now. It seems to have about the power that is should on my 16 foot boat. However, as it gets up to speed and the load on the prop decreases, I hear a pinging noise that is rather noticable and seems to be coming from the top of the motor. I've pulled on the pull start (it is an electric start) to see if it could be the clutch mechanism that is mounted on top of the flywheel. I pulled on it while the motor was running and the pinging persisted as usual. The noise sounds unsusual to me. I DO have the correct fuel/oil mixture and the carborator is adjusted 1 1/4 open as per the instructions on the carborator housing. Any suggestions as to what this noise may be? I'm looking for something under the flywheel that may be the source of this pinging. It sounds as if it is something metal to metal. Thanks in advance for your ideas.dean