Onan Generator starts hard

Well... I changed the oil today. Works good so far. Used some Sea Foam after changing the oil. Used a lot of Carb cleaner before the change... Crossing my fingers...

I was able to start it and put some sea foam in the oil and will be changing the oil. I also bought some carb cleaner and squirted it in the carb while the engine was running. I inspected the fuel lines and they seem to be ok. Will be changing the oil tomorrow after running the generator for a while. Sea Foam bottle says it's ok to use before and after an oil change.

You might also find the rubber gas line has deteriorated and is sucking some air. We had that on a previous Pace Arrow at 8 years old.

Thanks.. Gonna try it. Thanks for the insight on normal two tries starting...

Walmart or any auto parts store sells Sea foam, it has been around for years, longer that me. What I do is spray the carb with it while it is running at temp then flood it until it stops running wait about 20 mins then restart. I then remove the gas line going to the main tank and insert it into a gallon container mixed with gas and Sea Foam. Run the genset for an hr under load you can clean,exercise,and determine how much gas your generator uses in an hr. You can also dump some in the crankcase at the same time then drain the oil. You will be amazed at how much carbon build up you will see in the dirty oil. As far as multiple starts. I press the start button for 15 secs then release then press again, it takes a min of two tries during normal usage.

Never heard of Sea Foam...

Here's what I describe as hard starting...

1. I know there is a direct relationship between level of shore battery charge level and ability for the generator to start.. Lesson Learned.
2. In spite of item 1, some times when the battery is charged sufficiently the starter grinds on and on and occasionally doesn't start. After such a time there is a strong odor of gas so I assume the problem is within the carburetor.
3. I also have come up with my own system of allowing the starter to run a bit and when it starts to catch but does not I let off the starter, let it sit a couple of seconds and try again and most times it starts right off.
4. I am wanting to correct this problem if possible as I am living in the RV and desire the generator to work as well as it can.

I know it's a learning process and I appreciate the thoughtful feedback...

Reply I have an 18 year old Kolar Generator without a prime button. After sitting for 4 months over the winter it took 4 tries to get it to start. I ran it for an hr under full load. I expect it will take 2 tries to get it to start for the rest of the season. Not sure how you define hard starting. You can run a can of Sea foam through the carburetor to see if that helps it start better.

Changed the air filter as well. No my Onan does not have a primer button or procedure. The dealer even misled me to think it did...

I don't know if your Onan has a primer but if it does, you should prime it for at least 12 0r 20 seconds. To prime, take the cover off the gen set and locate the STOP/PRIME switch, now you push and hold down the STOP/PRIME switch, you should hear the fuel pump click, hold for at least 15 seconds or until the fuel pump stops clicking, then push the START switch and let it crank for a short time until it starts. Give it a try.

psalm10720 wrote:
I have a 1993 Brave with an Onan Generator and I have changed the spark plug and fuel filter and sometimes the generator starts very hard. I was thinking that maybe the floats in the carburetor may not be working well or some other fuel related problem. The motorhome has about 108,000 miles.

Once the generator starts it works well..

Hopefully, you change the oil sometimes. How about the air filter?
Also, older engines may have ring wear and need oil to develop proper compression. I would expect a harder start after sitting a long time and easier once the rings hold some oil.