2003 6 HP nissan four stroke, runs for 1 minute

[mikerino]

And there seems to be water in the oil, I tool out the oil cover while it was hot and oil came pouring out. I had just changed the oil but it seemed like a lot more came out afterward than I had put in.

We made sure that the gas vent was opened and we made a new very short fuel line to make sure we didn't have an air leak.

Suggestions? Cracked head maybe? Head gasket?

I read the making oil thread, dos that process happen fast like an hour?

Mike

 

[TOHATSU GURU]

Re: 2003 6 HP nissan four stroke, runs for 1 minute

It's extemely rare for a 4-stroke to make oil via water intrusion. It's much more likely that you will make oil due to fuel intrusion from the engine running too cool. Your best bet is to completely drain all of the oil. Re-fill only to the bottom hashmark of the engine dipstick. Run the enine for an hour and then re-check it.

 

[mikerino]

Re: 2003 6 HP nissan four stroke, runs for 1 minute

You don't think that it could be a cracked head or bad head gasket?

 

[TOHATSU GURU]

Re: 2003 6 HP nissan four stroke, runs for 1 minute

It's possible...but very unlikely. The engine would have to have gotten very hot to crack a block or blown the HG. Four-stoke engines run too cool because they use a raw water cooling system. All brands, in all sizes are subject to fuel dilution on a regular basis if they run at 1/4 speed or less for over 30 minutes at a time. It's one of the reasons I loathe 4-strokes.

 

[mikerino]

Re: 2003 6 HP nissan four stroke, runs for 1 minute

Thanks for the advice, I put 3/4 of a quart of oil in, just until it registered on the dipstick and took it for a ride. It starts good and will run at < half throttle (any more and it bogs and stalls) for about a minute before backfiring and stalling, then it will start up again with a repeat performance.
Time to rip the carb off?

 

[TOHATSU GURU]

Re: 2003 6 HP nissan four stroke, runs for 1 minute

I would start there. 90% of the time the problem ia a clogged up carb.

 

[mikerino]

Re: 2003 6 HP nissan four stroke, runs for 1 minute

Well, put a nice new carb on and it did not help.
Current symptoms, starts easy idles good. Up to almost 1/2 throttle bogs, stalls and backfires. If I run slow it will still eventually bog anyways. I have replaced the carb (as stated above) fuel line and tank. It seems like a fuel delivery problem. Will this motor backfire if starved for fuel? How about the filter or pump? Maybe an air leak inside the motor?
Thanks for any info anyone cares to share.

 

[TOHATSU GURU]

Re: 2003 6 HP nissan four stroke, runs for 1 minute

Backfires are almost always an ignition problem related to a broken flywheel key or a bad trigger coil. But, random replacement of parts is going to cost you more than if you had the engine repaired at a dealer.