4-stroke 6 hp

Started by busumark, December 06, 2009, 20:35:59 CET

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my friend has a 4-stroke 6 hp motor that he uses as an auxiliary and for trolling. he bought it new about one and half years ago. he made the first service oil and oil filter change done by the dealer. after about using it 5 times he noticed that the engine oil (beda jonqos. translate) and he had to top it up before using it and it smokes a bit when he starts it. he went to dealer with the motor and he said to him that there is nothing wrong because they left it working in a tank for an hour and the oil remained the same. after that he used it once and in 5 hrs the oil went from the top mark on the dip stick to the bottom mark. is it normal for this type of motor that the enigine oil ( jonqos translate ) at this rate. Does anyone has a 4-stroke 6 hp and can tell me what their motor does? so that he will know what to tell the dealer so that he wont take him for a ride for the third time in one and a half years


Doesn't sound right at all, and beda jonqos can best be described at least how I read it as: 'The engine oil was reducing' or perhaps to be more clear burning off.

Is the oil clean? In other words during this problem if he pull the dipstick does the oil still look clean? to eliminate the head gasket.

Are there any noticeable oil leaks in the engine cowling to see if oil is dripping from a bad o-ring or other seal?

If we focus on the smoking/burning of the oil, is this white smoke? Could be that oil is getting into the combustion chamber and being burnt whilst under compression. I would do a compression check as it should show up if there is a leak with reduced compression. For oil to be getting in to the combustion chamber, maybe then have a look at the rings/sleeves.

The only way I know of this happening ruling out a component failure is having run the engine with no water (eg. having caused it to overheat), which may then have caused these problems. Warped rings/sleeves etc perhaps?

But bottom line, no this is not normal and yes there is a problem. If you don't have any luck with the dealer you can always get another mechanic to perform an evaluation and provide a report, but he cannot make any repairs if you want to claim under warranty.


ok thanks i checked with two persons who have a small 4-stroke outboard and they said that the oil doesn t change. he will try again with the dealer.


The whole concept of 4 stroke means that your engine oil should not get lost but rather be re circulated within the engine. So no the oil level should stay the same. The oil gets burnt away in an old engine but the rate you are implying makes me think of something serious like a blown gasket .If the engine is blowing smoke it's probably being burnt with the fuel mix in the combustion chamber. Did the engine loose strength ? it is probably the rings in that case so long as the spark plugs are not gummed up.
13 Foot Seastar 400 (bahri kind of)
15hp Suzuki
3.5hp Seagull 40+ Longshaft  (Yes it works , yes it leaks oil)
3.0hp Seagull 40  Longshaft 60 years and it's my best one !
1.5hp Seagull 40- extra short shaft
5 hp Gutbrod Short shaft Air cooled.

Destination Sea

In the older days during the running in period there used to be a slight consumption of oil until the engine beeds in. However today due to more precise tech specification oil consuption is neglegable.
Oil can be consumed in four different ways
leakage to combustion chambers  broken rings/oil control  wear on cylinders / head gasket
external leakage
choked up crankcase breather (will cause exsessive buildon presuure)
defective fuel pump if mechanically driven
since most engines have a through prop exhaust smoke colour is not that clearly seen.
However if motor is run on headphones it should bee seen. Blue smoke shows that oil is being burnt with the fuel.
one can also check oil deposits on the spark plugs. 

Another point i will mention. You stated that after the service he noticed this happening. Could it be that the engine was overfilled with oil during service? and  it is being topped up under the wrong impresion of the max mark. Smoke on start up could also be that a valve stem oil seal is damaged.
Hope this helps.

Marino Iside 500 - Etec 90
Buccaneer 130 - Mercury 20


went to dealer to tell him when to take motor and i told him about the problem again. at first he was trying to tell me a lot of b****t as always but when i told him that i spoke with 5 persons that have a small 4-stroke and a meccanic he didnt say anything more and told me to take it to-morrow. when i told him about the oil the first thing he told me was but for how many hours the the motor was running 5 hrs ? he was trying to tell me that the oil level went down because it worked for 5 hours because when they checked it ( running in a tank for 30 minutes ) the oil level remained the same. they really have modern equipment to check an oil leak leaving a motor running in a tank for 30 minutes. than he told me for 5 hrs is not normal for oil level to go down but after 10 hours it can get down. when i told him that even in a year those who i spoke to never added oil he told me ok bring the motor and we leave it running in a tank for 5 hours ( again their modern way of checking oil leaks ) i told him no we want a pressure test and compression test. finaly he said ok i will tell the mechanic what to do but i have my doubts because he didnt know what we were talking about. i will let you how this finished


Well the dealer has accepted the engine to check it and that's something. Is the engine still under warranty? remember that a customer has to be satisfied with the actions taken by the dealer before taking the engine away. So if you're not satisfied, the engine stays there and they have to continue investigating. Discuss with the dealer the possibility of getting a 2nd opinion, perhaps anoher mechanic can come down and they can discuss together. Failing that, then it's time for the manufacturer to step in and help diagnose.


First thing I would go for is a compression test. Most Mechanics can do a compresison test for you. What you are describing should definitely show up clearly in a compression test. 
Seabrave 14 e-Tec 50hp


took motor to-day to dealer and he said again that he was going to try it by letting it idling in a tank for 5 hours. when i told him to make a compression test or pressure test to make sure what the problem was as this was the right mechanical way to check and not by starting the engine in a tank he told us that to make a pressure test you have to open the engine and he doesnt like to open a new engine. (maybe another excuse). even when my friend told him that the tensioner that he said that he fixed was not working good he tried to blame my friend because he told him the part he changed was original and he wasnt with him when he used the motor and that only my friend's motor from all that he sold had this problem so it must be that you are doing something wrong with the motor. when he saw it than he told us ok maybe the tensioner is not good. yes the motor is still under warranty

Destination Sea

Busumark tell him to stop pissing around. There is a test instrument called engine cylinder leakage tester (costs about GBP 60) Basically it has a gauge and a pipe which fits into the sparking plug and can measure the % of the leak if any. No need to strip the engine. A compression test does basically the same. Is the motor 2 cylinder?Cylinder pressure should be nearly the same on bothe cyl.. if   lower (than manufaturer specf.)and similar readings are obtained it should indicate a faulty head gasket.
Marino Iside 500 - Etec 90
Buccaneer 130 - Mercury 20


i dont think that he ever heard about that instrument


busumark can you share the brand of the outboard?
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i will not name the brand or dealer now i will wait and see what are the results. its not the first time that when someone wrote on this forum about a bad experience with a dealer that dealer writes in the forum or joins as a member just to answer that thread and comes up with a lot of nice words and excuses and tries to make beleive that the customer was at fault not him. so till now i will only tell how the things are going between my friend and the dealer. if the dealer is reading this thread i hope that he doesnt fix my friends problem just because it is being followed in the forum but threats everyone the same and give them a good service


Leaving an engine idling for 5 hrs will definitely damage the engine. The water in the tank will get hot and will cause the engine to over heat unless he has a circulating pump that continuously change water. and still 5hrs at idling speed is not good for an engine.   
Buccaneer 147 powered by Yamaha 85


Strip the engine for a compression test?? I'm not an expert, but I suggest you try and get some expert advice as I think this guy is making a feast out of you.
Seabrave 14 e-Tec 50hp