Fuel problem with my scooter?

[JonB_in_Glencoe]

227317

I've had this 2003 Honda Ruckus scooter for 3+ years. I love it, to run around town with, running errands and such. For only 49cc it is pretty peppy with an old fat man driving it. BUT, it has been running lean for the last month, especially when travelling at full speed for several blocks, and seemingly, "HOT days" (90º) make this condition worse. A couple times, it has stalled at a intersection and won't re-start for 5 or 10 minutes, making me think it was vapor-lock. I also wondered if I got some bad gas?

I had been using regular ethanol gas all summer. So I tried siphoning all the gas completely out of the tank and then refilled with fresh gas (non-oxy)...I even did it twice. It would seem to help at first, then the problem returned.

I was about at my wits end, then I looked to google
...guess what...
the electric fuel pump is a common problem. In the Ruckus forums, many fuel pump symptoms others had, were similar to mine. So I've ordered a pump and filter.
I hope it solves the problem? but I am a bit skeptical... I would think if a pump goes out, it goes out...not create a lean gas problem?

Any other thoughts?
I'll post an update when I receive the pump and get it installed.

[mattw]

I have farmed a good chunk of my life, but have not for the last 10 years or so. When the primary filter goes on a diesel farm tractor it just quits. Roll forward to this year... my '07 diesel grasshopper had been running lean, kinda weak. I did not even give the filter a thought.. out of desperation I changed it. OMG back to full power instantly. Did not expect that behavior. Lesson for me... change the darn thing!

[metricmonkeywrench]

Is it a 2 or 4 stroke motor? After confirming the fuel system is up to snuff I would also recommend replacing (not clean and regap) the plug. In some small motors the anti-pollution additives build up on the plug tip and weaken the spark. For what ever reason these deposits don't burn off like they do in an automotive 4cycle application.

In all my small motors I have moved to the more expensive but better ethanol free fuel with a maintenance dose of the Sta-bil Marine (blue) which is more effective against water in the systems, the pink stuff is ok but I have had better results from the blue. the problem centers around the ethanol's tendency to separate out and leave water in the system which reeks havoc in the fuel system. Over time because of these deposits you may have to re-adjust the carb (expecially for a 2 cycle) to make it run right.

[Dieselhorses]

I agree with metricmonkeywrench. Unless you have a fuel cut off and burn all remaing fuel from carb switch to ethanol-free. Mean time run some sea foam through it.

[JonB_in_Glencoe]

The Ruckus is a 4 cycle, liquid cooled motor. It's one of the selling points that sold me on this scooter.

I did pull the spark plug...It 'looked' good, I sprayed some carb cleaner on the electrode and rubbed it with a custom curved pointy tweezers, then flush again with carb cleaner (my usual plug cleaning technique for small engine spark plugs).

[JonB_in_Glencoe]

I agree with metricmonkeywrench. Unless you have a fuel cut off and burn all remaing fuel from carb switch to ethanol-free. Mean time run some sea foam through it.

Sadly there is no fuel shutoff valve, The Tank is lower than the Carb, pump is needed to pump up fuel to carb.
I did treat the gas with Seafoam, both times I siphoned the tank...as mentioned in OP, I syphoned the tank twice, to hopefully dilute the remaining ethanol even more.

I will be able to completely remove all the fuel when I do the fuel pump...a youtube video shows it's not a simple job, the seat and all the plastic needs to be removed, Tank also(tank is under the plastic floor boards), Pump and filter are under the tank.

[rockrat]

I have had problems with a Suzuki king quad, at times. Last time, I suspected the plug. Pulled the old one, cleaned it well, sprayed carb cleaner on it, gapped it, without success. Pulled the plug, put a new one in, worked just fine.

I believe that with low fuel pressure, your fuel level in the carb will be lower and will not deliver the amount of fuel needed for a correct air/fuel ratio and the engine will run lean.

[country gent]

A lot of the newer motors with fuel pumps also depend on a certain fuel pressure to work correctly. a weak fuel pump may not supply the needed pressure to get a good mist of fuel. Same witht he fuel filters partialy plugged may restrict flow to carb.

[bdicki]

Clean the carb

[robg]

With modern plugs cleaning is a waste of time just replace it .you should be able to here the fuel pump whirr. When you turn on the ignition ,if you can't its the pump ,might be worth checking the air filter just in case its damaged .

[Minerat]

My 650 Rincon honda would not low idle. Took carb off and took the fuel bowl off and it was covered with this yellow crud. Used spray carb cleaner to clean the bowl, jets and other parts of carb under the bowl and put it back on. It ran like new after that. Dumped all the C2H5OH gas and went to nonoxy 87 octane gas with 2 oz seafoam to a full tank if it is going to sit for more then month. That yellow crud was from the C2H5OH gas.

[JonB_in_Glencoe]

I hope I don't have to clean the carb...Wholly smokes
https://www.youtube.com/watch?v=8nnYqCC_sCU

I use ethanol in the summer, since this scooter is driven nearly everyday. Ethanol's biggest evil is the lack of shelf-life, I have had no problems with it, as long as it's fresh.

In previous years I've ran the last tank with NonOxy fuel and topped off the tank right before storage, I add some Seafoam then to stabilize the fuel for winter storage.

With all that said, If the pump and filter don't solve my problem, I suspect I may have to clean the carb.

[JonB_in_Glencoe]

A lot of the newer motors with fuel pumps also depend on a certain fuel pressure to work correctly. a weak fuel pump may not supply the needed pressure to get a good mist of fuel. Same witht he fuel filters partialy plugged may restrict flow to carb.

This isn't fuel injected, the pump just lifts the fuel to the carburetor, which has a bowl(of sorts) with a float.
https://www.youtube.com/watch?v=VI_lUZTFpZI

[abunaitoo]

I'm surprised it has an electric fuel pump.
Most scooters/mopeds have vacuum pumps.
We can't ride scooters like that here. No quads either.
Mopeds have to be licensed.

[JonB_in_Glencoe]

It is licensed as a moped (since the engine is less than 50cc) and insured for road travel per Minnesota state law.

[Iowa Fox]

Jon if that thing has a fuel filter I wouldn't do anything until I changed it. Filters are a maintenance item there for a reason, when they start to plug they restrict fuel flow. A plugged filter is just doing its job.

[lylejb]

Recently we had one of these at work. Was doing much the same thing, would fall flat on accel. A couple of my co workers (GMC techs) took on the task. At first, they removed, disassembled and cleaned the carb. A little better, but still not fixed. Next they drained the tank, and replaced the fuel pump. No help. It still acted lean, so the replaced the carb. It helped, but still wasn't right. After much hair pulling, they sent it in to the Honda dealer. Seems they adjusted the "nonadjustable" carb. Problem solved. I think it was a bad carb, and the new smoged out carb was as lean as the old.one.

[Lloyd Smale]

weak fuel pressure can cause a lean mixture problem which can cause a motor to run hot which will cause vapor lock.

[WebMonkey]

fuel pump all the way.

i'm confident you'll be fine after the swap.
:)

[JonB_in_Glencoe]

Recently we had one of these at work. Was doing much the same thing, would fall flat on accel. A couple of my co workers (GMC techs) took on the task. At first, they removed, disassembled and cleaned the carb. A little better, but still not fixed. Next they drained the tank, and replaced the fuel pump. No help. It still acted lean, so the replaced the carb. It helped, but still wasn't right. After much hair pulling, they sent it in to the Honda dealer. Seems they adjusted the "nonadjustable" carb. Problem solved. I think it was a bad carb, and the new smoged out carb was as lean as the old.one.
That is interesting.
one of the youtube videos I linked to, is to re-jet the carb.
I wonder if that is what the Honda dealer did?

But all I can say, after looking at that Carb video...is that is one complicated carb for a 4 cycle, single cyl, scooter gas engine.
But, it does get some crazy good gas mileage...somewhere around 100mpg, for around town, stop and go, short trips all under two miles each.

[DerekP Houston]

Is it a 2 or 4 stroke motor? After confirming the fuel system is up to snuff I would also recommend replacing (not clean and regap) the plug. In some small motors the anti-pollution additives build up on the plug tip and weaken the spark. For what ever reason these deposits don't burn off like they do in an automotive 4cycle application.

In all my small motors I have moved to the more expensive but better ethanol free fuel with a maintenance dose of the Sta-bil Marine (blue) which is more effective against water in the systems, the pink stuff is ok but I have had better results from the blue. the problem centers around the ethanol's tendency to separate out and leave water in the system which reeks havoc in the fuel system. Over time because of these deposits you may have to re-adjust the carb (expecially for a 2 cycle) to make it run right.

In my very limited small engine repair I agree, spark plugs are cheap enough I just toss a new one in for 2 cycle's whenever I'm doing maintenance.

[funnyjim014]

Clean carb. Replace plug. Fresh fuel. The new E10 fuel does not agree with carbs.