Message Board: Machinery: [CLOSED] Honda Strimmer problem
1st Jul 2009 by Mike A
Hi guys,
My apprentice reported a fault with our Honda strimmer to me earlier today. It is a four stroke, and it seems that the air filter/housing is soaked with oil. I have only glanced at it briefly so far, and will be spending some time on it this afternoon.
I have it in my head that it could be possible piston ring failure (?), but are there any other areas that I should be looking at before diving in head first?
Thanks
He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
1st Jul 2009 by Sumomosr
First of all, verify that the oil level in the crankcase is absolutely correct and not overfull.
Then check/clean the breather assembly.
Was it stored incorrectly? Upside down for instance, over a weekend or in the trailer etc??
GOGGA
1st Jul 2009 by Mike A
Hi Sumo, thanks for the response.
I have had a play with it earlier today. I cleaned the oil filter, breather assembly and spark plug - the plug was covered in oil. Whilst the plug was out, I pulled the starter cord to check it was turning over ok - this seemed fine. I also drained what oil was left in the crankcase and replaced it to the correct level. When I checked the oil level initially, it was on the low side, but I expected this as the air filter housing was literally swimming with oil.
Once I put everything all back together, I found it was extremely difficult to turn over with the pull cord. I eventually got it to turn over, and ultimately up and running. I ran it for a minute or so - there was a lot of smoke (white/blue), and a distinct knocking noise from the engine.
Our strimmers 'should' be stored on a flat surface, and not be left on their side/upside down for any period of time, but the reality is that this doesn't always happen unfortunately. I couldn't honestly tell you that if it had been stored in the correct manner following it's last outing.
Through questioning the lad that was due to take it out, he went through his basic pre start checks, and he assures me that everything seemed in order. Once he had checked everything, he fired it up and left it running on idle to warm up before commencing work. Whilst it was idling, he tells me it was "running smokier than usual". He says that it cut out, and as he tried to restart it, he noticed oil pouring from the air filter housing, and found difficulty in turning the engine over. It was at this point that he called me.
I must also add that this strimmer does have a history of running smokey at times, but I had diagnosed this as it being overfilled with oil, and all staff have been advised to keep a very close eye on the oil level in this machine.
He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
2nd Jul 2009 by Sumomosr
Excessive smoking is probably from the oil having leaked through the engine when (if?) it was stored incorrectly which is what normally happens. This oil will have been pumped into the muffler where it is being burnt off subsequently when the engine is running. The oily spark-plug is further evidence that oil is draining past the piston rings during storage.
My experience is that when the engine is started following a 'drain-past' such as this there is still oil in the piston ring grooves which acts like a syringe and continues to pump oil past the piston into the combustion chamber until the oil warms up and if you stop the engine the warm oil will drain out of the piston grooves and the smoking ceases upon restarting the warm engine.
Hopefully, correct oil levels and correct storage angles will alleviate your problem.
The knocking may also become reduced when the excess oil is clear of the piston, combustion chamber etc.
If it doesn't - take two asprin and see a (Saw)doctor in the morning.
GOGGA
2nd Jul 2009 by Sumomosr
Excessive smoking is probably from the oil having leaked through the engine when (if?) it was stored incorrectly which is what normally happens. This oil will have been pumped into the muffler where it is being burnt off subsequently when the engine is running. The oily spark-plug is further evidence that oil is draining past the piston rings during storage.
My experience is that when the engine is started following a 'drain-past' such as this there is still oil in the piston ring grooves which acts like a syringe and continues to pump oil past the piston into the combustion chamber until the oil warms up and if you stop the engine the warm oil will drain out of the piston grooves and the smoking ceases upon restarting the warm engine.
Hopefully, correct oil levels and correct storage angles will alleviate your problem.
The knocking may also become reduced when the excess oil is clear of the piston, combustion chamber etc.
If it doesn't - take two asprin and see a (Saw)doctor in the morning.
GOGGA
2nd Jul 2009 by Mike A
Ok, i'll have another look at it this afternoon.
Thanks Sumo.
He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
2nd Jul 2009 by Aladdin
Compression test?
From the posh end of the room!!
2nd Jul 2009 by Mike A
I did think of that Aladdin, but were not kitted out with that sort of gear.
I've had another go at it this afternoon, following Sumo's advice, to no avail. I can only conclude that it is piston ring failure, and carrying out that type of repair is getting beyond my comfort zone. Off to the service centre for this one.
He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
Back to Top - Go to Next Unread Message
This Message is closed, you may not post a reply at this time
