Help! Onan 4K generator refuses to start and stay on

[Kennyg]

Here I go again. Am at home now and I tried the generator again. It started, but only for about 15 seconds and then shut down. During this short time it ran rough and the exhaust blew constant blue smoke which I assume is excessive gas. As I stated before I did take the carb apart an soaked in cleaner and blwe air thru all the holes. So, where go I go from here?
Should I be replacing the carb or pull the carb entirely from generator and soak it in carb cleaner. Nothing seems to work.

[CharlesinGA]

Motor will shut off after a few seconds if the oil level is at the full mark. These motors like the oil level just barely above the add mark. Dozens of Youtube videos about this.

Charles

[WinMinnie02]

I had the same issue, not starting easily. I changed the spark plug, changed the air filter, and changed the oil. Then run it monthly for 30 minutes with a load. Treat the generator nicely and it will treat you well. I always use 87 octane over the last 20 years.

[pianotuna]

JaxDad,

The "lie-o-meter" type units do at least give a comparison of fuel economy.

That said, after treating premium fuel (no ethanol, where I live) with sea foam, after 18 months I had to add a produced called "heet". Before I added it the generator would not keep running.

[JaxDad]

whemme wrote:
Well the misinformation never ends. I agree that ethanol is hydroscopic but in order for it to absorb any significant water it would have to be exposed to the outside atmosphere in order to absorb it. 10% ethanol gas is stored in under found tanks with limited exposure to moisture. Also if it were possible for the ethanol to absorb enough water to reduce the mpg range of the fuel by 30%, since the fuel only contained 10% ethanol to begin with, mathematically the only energy remaining to propel the vehicle is coming from the gas and no energy coming from the ethanol content.

And finally if the water laden fuel actually is reducing the mileage by 30%, it will affect all vehicles using it equally not just fuel hungry motorhomes.

Your answer is predicated on ‘buying the party line’, not facts.

Sure IF there’s only 10 ethanol the amount of water is limited, but if the fuel has been spiked, the water content goes up too.

The water is a very real thing, some studies have shown that up to 50% of underground storage tanks leak. The below regional study found 20% of stations had water-laden tanks.

The problem is two-fold, higher ethanol rates means more absorption and leaking tanks mean an endless supply of water.

Report on leaking gas station underground tanks.

Very few people even track their mileage let alone test it on both types of fuel, with and without ethanol.

[whemme]

JaxDad wrote:

whemme wrote:
So you should see only a 3.3% mileage increase using ethanol free fuel - not 23%. If you are seeing a 23% increase you are somehow creating extra energy and you should patent your process.

All of that can be explained in one word, “adulteration”.

Energy content is calculated based on lab calculations, sort of like the amount of horsepower a vehicle is stated to produce, based on perfect conditions in a test cell.

Ethanol is a gift from heaven for gas station owners. Ever wonder why a huge percentage of gas station owners come from just one region of the world? Or why they happily pay seemingly ridiculous prices to buy those stations?

Ethanol. Anyone can buy it, no questions asked. When’s it’s blended into gas it sells for the same price as gasoline which is about $0.50 more than ethanol. Unfortunately it’s very hygroscopic, it likes water so much it will absorb it right out of the air. Water has a very low energy content.

The bottom line is that fuel, spiked with water-laden ethanol, can easily reduce mileage by 30% in fuel-hungry vehicles like motorhomes.

Well the misinformation never ends. I agree that ethanol is hydroscopic but in order for it to absorb any significant water it would have to be exposed to the outside atmosphere in order to absorb it. 10% ethanol gas is stored in under found tanks with limited exposure to moisture. Also if it were possible for the ethanol to absorb enough water to reduce the mpg range of the fuel by 30%, since the fuel only contained 10% ethanol to begin with, mathematically the only energy remaining to propel the vehicle is coming from the gas and no energy coming from the ethanol content.

And finally if the water laden fuel actually is reducing the mileage by 30%, it will affect all vehicles using it equally not just fuel hungry motorhomes.

[pnichols]

JaxDad wrote:

pnichols wrote:

JaxDad wrote:

whemme wrote:
JaxDad,

In most states 10% ethanol is also added to premium gas. Secondly, for vehicles calling for the use of 87 octane regular gas, using premium fuel absolutely will not increase your mileage. Premium fuel also is not any ‘cleaner’ than regular fuel that some believe. The only difference in the two fuels is the higher octane (anti-knock) rating and the approximately $0.60/gallon extra cost that you are just wasting using premium.

I beg to differ sir, I have physically checked my mileage MANY times running both ethanol enriched and ethanol free gasoline.

My mileage increases about 23% by running ethanol-free fuel.

So here’s how that plays out in my case, round-trip to south Florida is about 3,000 miles.

My rig gets 7.32 mpg on regular gasoline with ethanol in it. So that trip is 410 gallons. If it has 10% ethanol then it’s 41 gallons of ethanol and 369 gallons of gasoline.

On ethanol-free premium my rig gets 9.0 mpg. That same trip then uses 334 gallons of only gasoline.

If your $0.60 / gallon is close then that trip costs an ‘extra’ $200. Except I bought 76 less gallons of gas. If we use a $3 / gallon average price that is $228.

So if I ‘waste’ $200 on premium but spend $228 LESS in fuel, it looks to me like I’m up $28....... and that’s before we get into the 35 gallons less gasoline and 41 gallons of ethanol I DIDN’T burn on top of the 334 gallons of ethanol free gas.

The only thing the current ethanol-enriched gasoline is doing is wasting food, making corn industry folks richer and making social media folks feel good.

What methodology do you use to locate premium gas with no methanol added ... on a long trip in any place at any time? And - I mean finding that without using all kinds of various cellphone apps such that you have to specially plan your route and/or travel timing around specific gas stations where it's sold?

As far as I know, one can't just pull into any gas station and find it's premium doesn't have ethanol added to it - at least in the Western U.S..

This website lists a bunch of stations all over North America that sell ethanol free gasoline.

Pure Gas Website

I'm aware of that Pure Gas source for locating ethanol free gas ... and that is exactly what I'm not interested in messing with -> routing of my RV trips special so as to hit particular gas stations. My RV'ing time is too valuable for that. (My credit card gives me 5 per cent back in points from all gas money charged on it, so I use any station that's convenient.)

FWIW, I'm really surprised that California, for example, even allows the sale of non-ethanol gasoline. In fact I used to think that it was a national clean air requirement that ethanol be added to all gasoline used in vehicles that travel on public roads.

[JaxDad]

pnichols wrote:

JaxDad wrote:

whemme wrote:
JaxDad,

In most states 10% ethanol is also added to premium gas. Secondly, for vehicles calling for the use of 87 octane regular gas, using premium fuel absolutely will not increase your mileage. Premium fuel also is not any ‘cleaner’ than regular fuel that some believe. The only difference in the two fuels is the higher octane (anti-knock) rating and the approximately $0.60/gallon extra cost that you are just wasting using premium.

I beg to differ sir, I have physically checked my mileage MANY times running both ethanol enriched and ethanol free gasoline.

My mileage increases about 23% by running ethanol-free fuel.

So here’s how that plays out in my case, round-trip to south Florida is about 3,000 miles.

My rig gets 7.32 mpg on regular gasoline with ethanol in it. So that trip is 410 gallons. If it has 10% ethanol then it’s 41 gallons of ethanol and 369 gallons of gasoline.

On ethanol-free premium my rig gets 9.0 mpg. That same trip then uses 334 gallons of only gasoline.

If your $0.60 / gallon is close then that trip costs an ‘extra’ $200. Except I bought 76 less gallons of gas. If we use a $3 / gallon average price that is $228.

So if I ‘waste’ $200 on premium but spend $228 LESS in fuel, it looks to me like I’m up $28....... and that’s before we get into the 35 gallons less gasoline and 41 gallons of ethanol I DIDN’T burn on top of the 334 gallons of ethanol free gas.

The only thing the current ethanol-enriched gasoline is doing is wasting food, making corn industry folks richer and making social media folks feel good.

What methodology do you use to locate premium gas with no methanol added ... on a long trip in any place at any time? And - I mean finding that without using all kinds of various cellphone apps such that you have to specially plan your route and/or travel timing around specific gas stations where it's sold?

As far as I know, one can't just pull into any gas station and find it's premium doesn't have ethanol added to it - at least in the Western U.S..

This website lists a bunch of stations all over North America that sell ethanol free gasoline.

Pure Gas Website

[JaxDad]

whemme wrote:
So you should see only a 3.3% mileage increase using ethanol free fuel - not 23%. If you are seeing a 23% increase you are somehow creating extra energy and you should patent your process.

All of that can be explained in one word, “adulteration”.

Energy content is calculated based on lab calculations, sort of like the amount of horsepower a vehicle is stated to produce, based on perfect conditions in a test cell.

Ethanol is a gift from heaven for gas station owners. Ever wonder why a huge percentage of gas station owners come from just one region of the world? Or why they happily pay seemingly ridiculous prices to buy those stations?

Ethanol. Anyone can buy it, no questions asked. When’s it’s blended into gas it sells for the same price as gasoline which is about $0.50 more than ethanol. Unfortunately it’s very hygroscopic, it likes water so much it will absorb it right out of the air. Water has a very low energy content.

The bottom line is that fuel, spiked with water-laden ethanol, can easily reduce mileage by 30% in fuel-hungry vehicles like motorhomes.

[enblethen]

OP's problem does not appear to be a fuel problem, but an oil issue. Overfilled possibly causing the oil to foam.

[pnichols]

JaxDad wrote:

whemme wrote:
JaxDad,

In most states 10% ethanol is also added to premium gas. Secondly, for vehicles calling for the use of 87 octane regular gas, using premium fuel absolutely will not increase your mileage. Premium fuel also is not any ‘cleaner’ than regular fuel that some believe. The only difference in the two fuels is the higher octane (anti-knock) rating and the approximately $0.60/gallon extra cost that you are just wasting using premium.

I beg to differ sir, I have physically checked my mileage MANY times running both ethanol enriched and ethanol free gasoline.

My mileage increases about 23% by running ethanol-free fuel.

So here’s how that plays out in my case, round-trip to south Florida is about 3,000 miles.

My rig gets 7.32 mpg on regular gasoline with ethanol in it. So that trip is 410 gallons. If it has 10% ethanol then it’s 41 gallons of ethanol and 369 gallons of gasoline.

On ethanol-free premium my rig gets 9.0 mpg. That same trip then uses 334 gallons of only gasoline.

If your $0.60 / gallon is close then that trip costs an ‘extra’ $200. Except I bought 76 less gallons of gas. If we use a $3 / gallon average price that is $228.

So if I ‘waste’ $200 on premium but spend $228 LESS in fuel, it looks to me like I’m up $28....... and that’s before we get into the 35 gallons less gasoline and 41 gallons of ethanol I DIDN’T burn on top of the 334 gallons of ethanol free gas.

The only thing the current ethanol-enriched gasoline is doing is wasting food, making corn industry folks richer and making social media folks feel good.

What methodology do you use to locate premium gas with no methanol added ... on a long trip in any place at any time? And - I mean finding that without using all kinds of various cellphone apps such that you have to specially plan your route and/or travel timing around specific gas stations where it's sold?

As far as I know, one can't just pull into any gas station and find it's premium doesn't have ethanol added to it - at least in the Western U.S..

[Grit_dog]

^Bingo. 23% fuel mileage increase is greatly overstated I believe.
And has nothing to do with the OPs post and query.

[whemme]

First I was referring to both premium and regular fuels both containing 10% ethanol. Fuels (both regular and premium) containing 10% ethanol have about 3.3% less energy (BTU’s) than fuels without ethanol. You can lookup the BTU energy contend on both types of fuel on the internet. By the way premium fuel contains the same energy content as does regular fuel. So you should see only a 3.3% mileage increase using ethanol free fuel - not 23%. If you are seeing a 23% increase you are somehow creating extra energy and you should patent your process.

[JaxDad]

whemme wrote:
JaxDad,

In most states 10% ethanol is also added to premium gas. Secondly, for vehicles calling for the use of 87 octane regular gas, using premium fuel absolutely will not increase your mileage. Premium fuel also is not any ‘cleaner’ than regular fuel that some believe. The only difference in the two fuels is the higher octane (anti-knock) rating and the approximately $0.60/gallon extra cost that you are just wasting using premium.

I beg to differ sir, I have physically checked my mileage MANY times running both ethanol enriched and ethanol free gasoline.

My mileage increases about 23% by running ethanol-free fuel.

So here’s how that plays out in my case, round-trip to south Florida is about 3,000 miles.

My rig gets 7.32 mpg on regular gasoline with ethanol in it. So that trip is 410 gallons. If it has 10% ethanol then it’s 41 gallons of ethanol and 369 gallons of gasoline.

On ethanol-free premium my rig gets 9.0 mpg. That same trip then uses 334 gallons of only gasoline.

If your $0.60 / gallon is close then that trip costs an ‘extra’ $200. Except I bought 76 less gallons of gas. If we use a $3 / gallon average price that is $228.

So if I ‘waste’ $200 on premium but spend $228 LESS in fuel, it looks to me like I’m up $28....... and that’s before we get into the 35 gallons less gasoline and 41 gallons of ethanol I DIDN’T burn on top of the 334 gallons of ethanol free gas.

The only thing the current ethanol-enriched gasoline is doing is wasting food, making corn industry folks richer and making social media folks feel good.

[Gjac]

What I do is add a 1/2 can of Seafoam in a gallon can when ever it runs rough then draw from that can instead of the main tank and exercise the genset under load for an hr. My genset rarely gets used and I have to look for ways to use it rather than exercise it for an hr each month. Two other things I would try is whenever it shuts down while it is still hot, check the spark I have had to replace my coil because it would not work when it got hot. The other thing to check does the fuel pump still pump gas when it shuts down. I had a loose hose clamp on top of the main tank than was loose, sometimes it would pump fuel and sometimes it would not. I ended up replacing the rubber line because it was 25 years old sometimes they can leak air due to age. Good luck.