Honda BF 25 burning oil

[Georgia Gregg]

I am the original owner of a 1994 that has run extremely well since day one. The only maintenance performed has been the routine stuff...annual oil, filter, lube per owners manual. A typical season up north consisted of one or two weeks of heavy use of mostly short runs - 2 to 5 minute runs, perhaps 20 times a day. Now in the South, operate it from March through October, slightly longer runs. Starting perhaps a year ago, I noticed oil burning upon starting a warm or hot engine (fyi - pull start). The exhaust clears up in 10 to 20 seconds, and it is a little rough until it burns off. After that, it runs fine. This occurs or nearly all re-starts over the course of a day. The next day, cold start, no issue. It does not 'consume' oil at a rate requiring me to add oil throughout the season.<br /><br />I m concerned that to even troubleshoot this is going to set me back big bucks, and that a ring job or other significant work is in my future.<br /><br />Any thoughts as to the likely root cause?

 

[hondon]

Re: Honda BF 25 burning oil

Start by moving your tilt pin out a hole or two.If things do'nt improve,then it is time for a general lookover meaning a valve adjustment,compression and leakdown test.You claim to be running well so I doubt this will turn into a big deal.Check your basics first.

 

[Georgia Gregg]

Re: Honda BF 25 burning oil

Hondon - thanks for the advice. I had moved the pin and am now wondering if that was when I started to experience the problem. I take it from your response that if this is indeed the problem the results will be immeadiate. What exactly is the problem of having the motor tilted in a way that places the back of the engine lower than the front?

 

[hondon]

Re: Honda BF 25 burning oil

This is not really a problem as much as the nature of the beast.Any engine with a vertical crankshaft will allow some motor oil to gravity flow back into the cumbustion camber if the situation allows.Your engine being tucked in may be creating that situation.I hope that answers your question.

 

[Silvertip]

Re: Honda BF 25 burning oil

The fact that this engine sees nothing but short runs (hence never getting really warmed up) would tend to cause some varnishing and possible ring sticking. Perhaps a decarb procedure might be in order. I would also suggest you periodically make a longer wide open throttle run to "exercise" this engine more.

 

[Georgia Gregg]

Re: Honda BF 25 burning oil

Hondon - I made the suggested adjustment and eliminated the oil burn-off at start-up. Thanks for saving me time and money.

 

[Georgia Gregg]

Re: Honda BF 25 burning oil

Hondon - another question... given the age of the motor, and given the only maintenance has been lube, oil, filter, what if any detailed diagnostic / tear downs should I be considering? The engine still runs extremely well, but who knows, perhaps it is way out of tune / carb adjustment.

 

[hondon]

Re: Honda BF 25 burning oil

You will certainly want to look at and change your gear oil.Take notice of any evidence of water intrusion there.If your valves have not been touched in this amount of time you are way over due.Carbs need no attention until they give you trouble .Please tell me you are using a water separting fuel filter.

 

[Georgia Gregg]

Re: Honda BF 25 burning oil

I change the gear lube annually....no evidence of water. I have not had any other mechanical work performed. Why valves...what is the failure or performance degrading impact? What is the impact of not having previously perfromed the work? As to the filter, unless it came from Honda that way, I am not using one. Is it a device that can be added in line?