Petrol smell from Honda generator

Submitted: Sunday, Jul 05, 2009 at 19:29
ThreadID: 70422 Views:11834 Replies:10 FollowUps:10
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I recently purchased a new Honda EU20i generator and get a strong smell of petrol fumes when I store it in the front boot of my caravan. The vent on the generator petrol cap is closed and I have also tried emptying the fuel from the fuel line using the small screw near the carby to drain the fuel out via the pvc hose. Do any other owners of this unit have problems with a petrol smell when enclosed in a confined space?
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Reply By: Member - Tony F (NSW) - Sunday, Jul 05, 2009 at 19:45

Sunday, Jul 05, 2009 at 19:45
Sorry I could not tell you why but I have the same problem. I have to carry it short distances in my LC Station wagon for work sometimes. The vent position doedsn't seem to stop the smell either. Good thing I don't have to carry it very far. The interesting thing is that if I do not open the vent the generator will not run for long . So that proves it seals well. I still have the problem though. Cheers Tony F
AnswerID: 373222

Reply By: Gone Bush (WA) - Sunday, Jul 05, 2009 at 19:48

Sunday, Jul 05, 2009 at 19:48
I've followed this question on other forums and it is a common thing with EU20s.

Mine does it too.

I saw one post where the owner took it back to the dealer and it was fixed.

I'm going to see my local Honda bloke this week and see if he can cure it.

I would take it back if I was you.

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AnswerID: 373223

Reply By: Member - Graham H (QLD) - Sunday, Jul 05, 2009 at 20:15

Sunday, Jul 05, 2009 at 20:15
Mine has been in the back of the Croozer for 4 months and only smell it a tiny bit on a hot day.
Drained the fuel and it stopped smelling after a week or so.
Used it a week ago for 5 hours and just chucked it in the back again and it hasnt smelt at all.
Either that or we have got used to it.
Yes I know its naughty but it has to be somewhere and no room in van for it.

Ps its 3 years old.

AnswerID: 373229

Reply By: Best Off Road - Sunday, Jul 05, 2009 at 20:15

Sunday, Jul 05, 2009 at 20:15
I've got an Honda "knock off", Kipor, it does it as well.

My chainsaw does it too.

I reckon it's a normal thing with petrol powered gear. My shed smells of petrol from my lawn mower and whipper snipper.


AnswerID: 373230

Follow Up By: jolo - Sunday, Jul 05, 2009 at 20:30

Sunday, Jul 05, 2009 at 20:30
I can understand some smell with other petrol appliances but the Honda generator is designed as a portable 240v power supply for vans etc and I would expect this to be sealed for storage in a confined space such as a van or wagon. I am worried about the strong petrol fumes in the van boot that has my battery and charger. Thanks for the response.
FollowupID: 640417

Follow Up By: Best Off Road - Sunday, Jul 05, 2009 at 20:56

Sunday, Jul 05, 2009 at 20:56
I doubt you have a problem.

I did some OH&S work with a "sniffer" designed to detect dangerous gas levels. We had to poke the nozzle of the sniffer many inches into the fuel filler of a car before it was dangerous.

That is to say, the woft of petrol is far from being explosive. Much like gas, you'll smell it long before it is even remotely dangerous.

FollowupID: 640421

Follow Up By: jolo - Sunday, Jul 05, 2009 at 21:07

Sunday, Jul 05, 2009 at 21:07
With the generator stored in the van boot, the petrol smell after a few hours is extremely strong and I need to open the boot lid at frquent intervals to dispel the fumes. While it may not be a serious problem with the battery & charger, the petrol smell gets into other equipment I have stored in the boot. I do not consider my nose to be super sensitive to petrol but I think the smell is excessive and my wife is very sensitive to the smell and I now have to leave the generator at home.
FollowupID: 640423

Follow Up By: Member - Uncle (NSW) - Sunday, Jul 05, 2009 at 21:12

Sunday, Jul 05, 2009 at 21:12
Rather than leaving the gennie at home, why not put a gennie box on the drawbar if you have room. Seen plenty of grey nomads do just that and it looks like a great idea.
FollowupID: 640425

Reply By: ian zzr - Sunday, Jul 05, 2009 at 21:33

Sunday, Jul 05, 2009 at 21:33
hi jolo, for 8 years i have owned a eu10 and i work on these also, it is normal to get fuel smell on hot humid days i also keep mine in the car when traveling , i always put it in when unit cold from using, on cool or cold days no smell on hot days you will get smell , its just the nature of the beast, and as said before the vented caps do work very well, But what i have done is, i had a heavey duty canvas bag made up with 4 fold over flaps like a card board box but over lapping down the sides slightly with 3 inches of velcro on each flap with a carry handle strap and this works a treat even on hot days .
AnswerID: 373243

Follow Up By: jolo - Sunday, Jul 05, 2009 at 21:57

Sunday, Jul 05, 2009 at 21:57
I get the strong petrol smell even on very cold days ie <15C or overnight when stored at home. As I mentioned before, I even remove the fuel from the carby as the Honda dealer suggested this should stop the problem. I will be taking it back to the dealer to look at again but was trying to get feedback from others to see if my problem was experienced by others. Thanks to all who responded and I get the impression that there are some units that have this problem as well. The extra box on the drawbar sounds like a good idea if it does not get fixed but space may be a problem.
FollowupID: 640434

Reply By: Ozboc - Sunday, Jul 05, 2009 at 22:05

Sunday, Jul 05, 2009 at 22:05
greetings guys -- not sure on this gen as i have a different one - but knowing most of these gens have float bowl style carbi's - do you guys just shut down the gen or do you turn off the fuel tap and let it run out of fuel ?

AnswerID: 373252

Follow Up By: warfer69 - Sunday, Jul 05, 2009 at 22:13

Sunday, Jul 05, 2009 at 22:13
Hiya Ozzie

I hav an EU20i also and was under the impression its not good to constantly let the piston (all petrol,mowers,whipper snippers etc) run dry of fuel all the time ?????....
Heard it somewhere..
FollowupID: 640438

Follow Up By: Ozboc - Sunday, Jul 05, 2009 at 22:21

Sunday, Jul 05, 2009 at 22:21
Greetings Warfer69 you are correct when it comes to 2 stroke motors .... when the fuel runs out the revs go higher or leans out - then with lack of fuel comes lack of lubrication ( pre mixed in the fuel ) - not to much of a prob if your a person who mixes a little rich but certainly not good for a 2 stroke motor -- 4 stroke is ok ....

on that Note -- NEVER EVER buy a display model 2 stroke ANYTHING mower brushcutter) none have had lubrication in cylinder ( or very little ) and people have a habit of "pulling the starter " to feel compression - after a few months( and 5000 pulls later) it totally destroys the cylinder and piston walls . when i was at Mc culloch - we would have them come back from Kmart -- NEVER been run nor had fuel in them - and look like they had been run on straight fuel when motor was pulled down

Hope this helps

FollowupID: 640440

Follow Up By: garryk - Monday, Jul 06, 2009 at 16:35

Monday, Jul 06, 2009 at 16:35
The suggestion by Boc on being wary of display models is something I fully agree with .
but I also include the 4 strokes as they are shipped with no oil in sump and if on display without oil and the same give it a pull customers are looking , well ? not for me
in fact I just bought a Yamaha 1 kva last month and even though the best price was for the one on display shelf
I purchased one at a slightly higher quote but still sealed in the box
You also never know what else some ham fisted clown has managed to damage while pokeing about

FollowupID: 640486

Reply By: jolo - Monday, Jul 06, 2009 at 17:02

Monday, Jul 06, 2009 at 17:02
I was able to borrow a Honda 20i generator from a neighbour to see if his unit had the same problem. Stored in a plastic bag under the same conditions on a very cool day, his unit had only the slightest petrol smell while I nearly got high on the fumes from my unit. I had the fuel drained from the carby on my unit but not on the neighbours. I will now see what the dealer can do to fix it.
AnswerID: 373326

Reply By: Flywest - Monday, Jul 06, 2009 at 20:13

Monday, Jul 06, 2009 at 20:13
Most small petrol powered machines leak petrol fumes.

It's inevitable in the design of the carby.

These machines have an inbuilt float and needle and seat which shut off or regulate the fuel supply to the jets, based on the fuel level in the fuel bowl.

they ALSO however have what is known as a fuel overflow, which drains excess petrol from the bowl via a small tube to atmosphere most often.

Thats coz they are mostly gravity fed, and the carby & bowl are below fuel tank height so it isn't possible to drain overflow fuel BACK to the fuel tank (it would have ot be oumped back up hill to do that).

So - with these 4 stroke generators, IF you don't run the carby bowl dry, bye closing the fuel tap and allowing it to run to a stall, (or opening the carby bowl drain screw after its stopped), it keeps a bowl full of fuel captured in the carby bowl ready to start next time and enclosed purely by the neddle and seat valve.

As it slops about with transport, the carby bowl float goes up 'n down, allowing small amounts of fuel, to go out the overflow and to the jets & you will smell this easily.

Also as it heats up during the day the carby bowl fuel will expand and go out the overflow - again you will smell this.

As soon as the fuel level inside the bowl drops - the needle and seat no longer closes the fuel in the bowl off from the jets and it can evaporate every day with heat etc out of the carby via that route, in addition to the overflow vent.


The trick is to keep the fuel contained within the tank and NOT in the carby at all, while transporting - your manual will probably mention this.

As stated run the carby dry (4 strokes not 2 strokes) by shutting the tap, or with 2 strokes, stop it then shut the fuel tap - then drain the carby bowl by opening the drain screw.

This should allow you to transport small power operated engines without the fumes, if all your hoses and connections are tight.


Fuel sniffers!

I have 2 of them (Actually gas sniffers) in the boat - 1 in cab and 1 under deck with the fuel tanks.

They are so sensitive to any form of combustible gas fumes (hydrocarbons) / it is unbelievable.

I once used CRC on the cabin door lock, and cabin window latches - the sniffer screamed every time it was activated prior to startup for weeks until the residual hydrocarbons eventually evaporated away by leaving the door and windows open 24/7.

I have those gas struts on the seats (pantograph seats out of a truck), and one of them blew a seal releasing just a weep of oil every time someone sat on the seat or it went up or down over a swell. The cabin gas sniffer became inoperable, it would just scream any time you turned it on - until I replaced the offending gas strut and thoroughly cleaned all the traces of oil from inside the cabin.

If you turn the gas sniffer on - when downwind of the engines after they have been running and the exhaust fumes enter the cabin - the sniffer will go mad!

After refuelling the boat any trace of spilled petrol - sets the sniffer off until it has ALL evaporated and thoroughly dried.

Attempting to carry ANYTHING with petrol or oil in it inside the cabin sends the sniffer mad, (i.e small generators or portable power tools).

In my experienc - that type of LPG type gas sniffer set to register hydrocarbons are so sensitive as to almost be considered "too sensitive".

I say this because the "temptation" becomes to make excuses such as lubricant on something etc and IGNORE the sniffer Because it takes so little to set them off.

Having seen the results when fuel fumes under deck ignite, I've been trained NEVER to ignore the sniffer and always track down the source of a sniffer signal - to the point I am anal about it - and I have found about 100 things other than fuel fumes below deck that will trigger the damn sensor thru trial and error - finding potential sources - removing them and re trying the sniffer..

I have lost many many hours of valuable sea time - chasing down whatever triggers that damned sensor - I've yet to actually have a fuel leak from my tanks under deck - but the day it comes I will be ready!

I couldn't speak hhighly enough of the type of gas sniffer fitted to commercial boats - you couldn't go past one for your caravan etc IMHO.

I did work on a Lobster Boat once where one of the crew left the LPG stove on all night after boiling a cray tail for lunch - the flame must have blown out and the boat bilge was full of LPG the next moring when we boarded to go to work.

The bilge sniffer saved all of us, I was able to quickly grab one of the crews lit ciggarette out of his gob and toss it overboard, as he attempted to open the deck hatches to ventillate the LPG fumes.

Theres some real bad results when fumes go bang in a confined space - best to get a gas sniffer and fit it and always obey it - even when it's a false alarm.

Draining the carby bowl and keeping the fuel trapped within the fuel tank and not allowing it access to the atmosphere via the carby needle & seat / jets route or the carby overflow route is the best way and if at all possible carry it in a well ventillated area outside of the confined spaces of caravans and vehicles.

A little tip - LPG etc is heavier than air, any container space with a sealed or semi sealed emclosure, that can have LPG bottles or liquid fuel placed in it - should have "air vents" fitted that drain those fumes OUTSIDE of the vehicle caravan boat etc.

It's a legal requirement on commercial boats that the LPG bottle enclosure is vented overboard, from its LOWEST point.

A similar rule for caravans and cars etc couldn't hurt. No doubt owners would complain to the builders that dust enters their precious van or car if they did that!

Sometimes you just can't protect people from themselves.

Nothing can be built "idiot proof" - theres a continual improvement process in place that builds ever more incredulous versions of idiots! ;o)

Those are the ones who escape Darwins law of selection of only the fittest to reproduce. LOL

Good luck with it


AnswerID: 373357

Follow Up By: Flywest - Monday, Jul 06, 2009 at 21:06

Monday, Jul 06, 2009 at 21:06
Something else I learned - about electrical sources that can and will ignite those trapped flammable fumes.

Guy I know of set his boat alight at sea off Darwin with a under deck fuel spill, resulting in an 18 hours swim and long barefoot walk thru the crock infested and oyster encrusted mangroves back to Darwin to get help.

It was a small 16 ft center console with an underfloor tank.

One of the fuel hoses split with age & perishing and there was maybe a half cup full of fuel floating on top of normal bilge water.

He lifted the floor hatch, when he smelled petrol fumes, and saw some of the fuel floating on top of the water.

He did make a precautionary "mayday call" on his radio, but hadn't got round to giving his exact position (1st mistake) - just mentioning that he had small fuel spill underfloor and MIGHT be needing help if he couldn't deal with it and a ROUGH location - said he would call again when all was under control.

He was worried that the triggering of the radio & mike, might set off a spark to ignite the fuel, so only made that first radio call and kept it short with no ECACT location (Lats and Longs).

Then he got worried about any stray electrical sparks, that might start a fire so decided to disable the starting battery system etc by turning the Cole Hersey type isolator switch off.

That was his 2nd mistake that nearly cost him and his mate their lives & what created the spark that set it alight.

His thinking was right - a fuel tank leak COULD elevate the auto bilge switch level as tho it were water under deck increasing in depth and cause the bilge pump to auto float switch start or trigger a high water alarm.

Such bilge pumps are designed to pump water not petrol - the electrical engine within is NOT spark shielded in any way, and more than one bilge pump has blown up a boat with a leaking fuel tank below decks before today.

His problem was - he had the WRONG type of Cole Hersey isolator switch fitted to his boat, it was an automotive type NOT a marine type.

There is a difference?????

You bet there is and to this day on automotive and rec boating sites in Oz I've never seen this mentioned.

There are two type of these battery isolators, automotive and marine.

Heres the difference for those who don't know.

Automotive are whats called "make before you break" isolators, and Marine are whats called "BreaK Before You Make" isolators.

As all offroaders know, these multiple battery setups utilise these cole hersey type switches to connect and disconnect various arrangements of multiple batteries.

The "Make Before You Break" type are set up to break one circuit before you connect and make the second circuit.

These can be a problem for some types of engines especially thosenewer types with sensitive electronically controlled computer ignitions and fuel injection systems etc and alternators with diodes etc.

It's not good for some of these to be without anywhere for the current to go when the alternator is spinning!

For this reason we hear of rules like:-

"Never siwtch thru the "OFF" position while the engine/s are running!"

This is because IF they break the first circuit before making the next circuit - we are momentarilly left with a alternator making current with no battery for it to go too.

Results can be spattered diodes in the alternator or loss of computer default manufacturer settings while there is a momentary power loss.

Another type of Cole Hersey type switch for marine use is the "Make Before Break" type - where the connector position within the switch is set such that the second circuit is made before the first circuit connection is broken.

This type allows a continuous flow of electricity, while the changes are being made.

The same Rule as above tho still applies because at the OFF position - the circuits ARE broken totally - so again regardles of the type of switch you should STILL "never switch thru the OFF position while the engine is running", no matter how fast you think you can twist it.

Using the Make before you break type of switch theres far LESS tendency for a spark to jump to the next connector because the crucuit is already open via the previous connector before it is broken - the next is already connected.

If you wanted too you could think of the make before you break type cole hersey switch as a "sparkless" connector and the agricultural auto type 4wd cole hersey break before you make variety as the "spark" type.

Using the wrong one (spark vulnerrable type in the WRONG application) i.e where any type of flammable fumes might be present, can be a very very BAD idea.

Now I will give you some examples to think about for the offroaders!!

Charging batteries emits oxygen gas - a invisible tasteless odourless but non the less explosive potential gas.

Lets say I build myself a offroad camper trailer, or buy one from a manufactuirer who knows nothing about the differences between types of cole hersey isolator switchs and uses the cheaper auto type.

Maybe you have a bank of batteries under the bed in a special built battery box / drawer arrangement?.

Guess what?

When you charge those batteries, while travelling thru a 7 pin aux power connection between trailer and vehicle or even while at rest - IF you have the WRONG (cheaper auto type break before you make type circuit connection) cole hersey type switch - and it's mounted within the van and you are unfortunate enough to switch it and create a spark in all that hydrogen gas - maybe it will be the last thing you ever do.

Same for second and 3rd batteries in the rear of utes with canpopy covers or tonneau covers or in the rear of enclosed 4wd wagons etc.

I see LOTS of cole herseys fitted inside 4wds - almost any vehicle with mutliple batteries and winches and fridges freezers and heaps of spotties etc etc seems to have them.

Haven't seen one yet that was a marine type Make before you break circuit switch of the Cole Hersey variety.

Those agricultural automotive break before you make variety should ONLY ever be fitted in the open air under a bonnet for example NOT within a enclosed passenger cab space where extra batteries are contained, and oxygen can be generated by charging the battery.

It would be far safer for all 4wd's to just fit the marine continuous circuit make before break type switch IMHO specially for those campers with batteries banks under the bed etc.

How many folks even know there is a difference??.

The guy with the boat and his passenger survived their ordeal - I can tell you 100% he will NEVER forget there is a difference and his NEXT boat he won't skimp and fit an automotive break before make type of Cole Hersey Switch.

Boats saw the black smoke from his boat fire on the horizon not long after his first mayday call, but because they didn't have any exact location, took some time to find the actual spot from his "rough location description" and by then he 'n the mate had made a swim for it, floating on the ice box, and the big tides moved them many miles in quick time - long before the searching boats got anywhere near their burning boat, it burnt to the water line and sank.

His stories about the 18 hour swim and the big sharks that came to "investigate and bump them" thru the night - are enough to curl your hair.

Simple things that we don't know can easily kill us.

Knowledge is no weight to carry around.

Do a little google searching about "make before you break marine battery isolator switches" and become knowledgeable.

You might be the ONLY one in your 4wd club who actually knows! ;o)

Cheers & beers
FollowupID: 640527

Reply By: veight - Wednesday, Jul 08, 2009 at 23:27

Wednesday, Jul 08, 2009 at 23:27
You said you borrowed a neighbours eu20I
if you can try swapping over the fuel cap to see if they make a difference
I had the same problem the seal inside the fuel cap was buggered from new.

Also the eu10I / eu20I / eu30I does not have a fuel tap you can turn on/off
to make the generator run out of fuel.

Also another tip I have seen people start these generators with load plugged into them - you start these generators with the "eco" switch turned off
once the generator is running you plug in what you want to run wait 10 sec or so then turn the "eco" on - when your finished switch eco back to off unplug what you are running then switch the generator to off.

AnswerID: 373695

Follow Up By: jolo - Thursday, Jul 09, 2009 at 19:22

Thursday, Jul 09, 2009 at 19:22
Swapping the fuel caps was one of the first things I tried. Seems to make no difference but thanks for the tip. I agree, trying to start the gennie with a load would not be the best idea.
FollowupID: 640956

Reply By: Member - Graham H (QLD) - Thursday, Jul 09, 2009 at 20:00

Thursday, Jul 09, 2009 at 20:00
Did you spill some petrol whilst draining it or when you originally filled it.

Since this thread started mine has been in the back of the cruiser and I cant

smell any petrol at all and it defintely has some in the tank.

As I said this one is about 4 years old so maybe they get better with age.

AnswerID: 373819

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