88 spl -ran gas out main tank now motor hard to start and run. even w new fresh fuel

[toddschubert]

I knew even w my regular maintenance my luck would run out on how well my J88spl always ran.
I purposely ran the gas out of main tank and have a pretty fine mesh glass filter inline so I feel comfortable that no sizable trash would get to the carbs. I switched to spare tank that had fuel/oil that is about 8 mos old with some seafoam additive. No filter on this line and when I tried to start it up after pumping bulb it was very difficult and I had to apply throttle which I never normally do to get it going. It ran very rough and I had to keep it above idle for the 10min ride to the launch.
After getting home and new fuel/oil in main tank it still is hard to start and runs rough when I do and will eventually quit.
It normally would start on second turn of switch and push of prime, bumping the primer a few times while it got warm.

Before I go tearing down carbs, what advice would you give me to look for or try given these circumstances?
What else might running out of fuel do to the motor or perhaps bad fuel in aux. tank? There is nothing visibly wrong with aux fuel and it smells and feels normal.
I have checked for spark and all cyl are firing and plugs look good. I hope that nothing coincidental went wrong with say power pack or something.

 

[rolmops]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

Could it be that when you changed tanks ,you got some dirt in the quick connector?

 

[toddschubert]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

That's my first thought. I do keep the connector in a plastic bag when it is not in use but it's possible.
Where would the likely place it would wind up? pump, carb jet?

 

[rolmops]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

That's my first thought. I do keep the connector in a plastic bag when it is not in use but it's possible.
Where would the likely place it would wind up? pump, carb jet?

It stays stuck in the quick connector or the bulb.Just try to run it with another hose and see what happens. If it solves the problem ,just clean the fuel line and you're on your way.

 

[toddschubert]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

I'm back on the main tank now which includes different connector, bulb, filter. Still have problems. It's in the motor whatever the problem is

 

[rolmops]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

What you want to do is go by trial and error, starting with the simple and/or cheap possibilities. that way you will easily eliminate the different possibilities.
You just eliminated the fuel line. next would be the inline fuel filter and then the screen on your fuel pump and so on.
One big possibility is the carburetor bowls that may have filled up with water out of the bottom of the main tank,so you should drain and refill those as well.

 

[toddschubert]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

Yes, clean. The problem is deeper than the obvious. Carbs I'm guessing but I could be missing something. I'm just not a good carb guy so I'm hoping for something else I guess. Thanks for your suggestions

 

[Big Fish Billy]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

Unfortunately for me, hopefully not you, running out of gas is like leaning out the carbs. I had a 1990 Nissan 8hp that ran perfect for 23 years, never touched a thing, not even the water pump impellor, until last Summer when I ran out of gas and it wouldn't start, acting like yours. Not much compression in one cylinder, normal in the other. I had nearly burned a pencil sized hole through the top piston, that tapered to a pencil point hole that did go through. Of course I was going full throttle when I ran out. So I guess for you, take a compression test first....and don't ever run out of fuel again.

 

[emdsapmgr]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

Possible you've got a spark issue. Easy/quick to check. Check for spark on all cylinders when cranking the engine. Easy/quick to do. A spark-checker device or an inductive timing light will show spark on each cyl when at cranking rpms. If you find good spark, then you know it's a fuel issue. Did the second fuel tank have any signs of water in it? Did you take a fuel sample from that tank?

 

[Triangleboater]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

I have ran 2 stroke's out of fuel probably 100's of times between my outboards, chainsaws, and so on and never had a piston burn a hole.... I think you may have sucked up some junk, happens fairly often. You have low speed passages in your carbs that are tiny and the least bit of junk will make your engine run funny. But, like the others have said, rule out the easy stuff first. Did you check the screen on the fuel pump? make sure fuel is flowing well to the carbs. check compression and make sure spark is jumping a nice gap. Then go to breaking down the carbs. Nothing like doing work for no good reason.

 

[emdsapmgr]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

Check the filter screen under the round inlet cap on the side of the fuel pump. If that gets plugged up, it won't matter which tank you run it on.

 

[toddschubert]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

back working on problem
All fuel issues up to the carb have been ruled out. The carbs get plenty of fuel.
I removed the carbs and cant find a single problem. They look like they are brand new. No gumming no nothing. All visible jets are clean as a whistle (if thats clean) and I can see light through them all. Except the needle valves which I have not removed yet.
Found card bowls (plastic models) to be cracked in several places. Just hairline but one leaks a little fuel at the drain plug location. I need to order new bowls I recon.
Back to my original question....What would running out of fuel at idle do to a motor? I guess there is no well known answer like (oh yeah the low fuel relay has to be reset) lol I am keeping in mind that a coincidence could have occurred and something like spark could have gone wrong. I did however test spark by unplugging each cyl. and there was a difference on every one so I assume spark is good.
I am ordering new bowls and o-rings
oh, and I found the primer pump face plate and valve to be leaking fuel when activated. I hope just the plate assy. is available and dont have to buy the whole pump.

 

[racerone]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

Running a motor out of fuel at idle does no damage whatsoever.---------The part is available to repair the electric primer valve.---This unit is not a pump as you mentioned.----Just do some simple trouble shooting here.----#1 is a compression test.-#2 is a spark intensity test.--Spark is no good if it can not jump a gap of at least 3/8" or more.

 

[emdsapmgr]

Re: 88 spl -ran gas out main tank now motor hard to start and run. even w new fresh f

OMC made these V4/V6 engines with plastic fuel bowls for a number of years in the very late 80's. Problem with them was that all of them become leakers at some point. Not so much a matter of if-but when. Leaks usually manifest themselves in fuel leaks at the big rubber bowl gasket. Also, possible that if the bowls warp a just the right spot, the carbs can suck air instead of fuel, causing a lean condition when running. Sounds like your bowls have found another failure mode-cracks. Good call to replace the bowls. You will find the replacement aluminum bowls will cause you one problem. The new bowls take a different mid-jet. The threads of the four 26C jets are different in the new bowls. Your old jets won't screw in. See your dealer to purchase a different set of four 26 jets (not sure if you need the "D" jet or the 8/32 jets.)