Suzuki fa50 oil pump/fuel line

I am back with more...

I got the moped running, cleaned the carb, the jets, and got new gaskets.

I have two questions now.

1) it will start and run fine for as long as I have it on, but then if I cut it off and try to re start it it won't start, even with starting fluid and the choke in all sorts of positions. It has a spark and compression. I tried to look at the fuel line it seems like maybe it's not actually sending gas through.

2) the person I bought it from was using pre mixed gas, how can I tell if the oil pump is properly working and he didn't know it had one, or if he disabled it? If he hadn't disabled it that means it's getting double the oil it needs which would make sense because when it runs it is very smokey.

Sorry for all the fuss, I just can't seem to find much on this bike and I've read over the manuals many times hoping to find something

Re: Suzuki fa50 oil pump/fuel line

If it runs then it's sending fuel. Restarting doesn't require more fuel strictly than running. If the oil mix is doubled up (why haven't you checked the pump output and dumped the mixed gas?) Then it will create a gooey fouled plug and that can be difficult to start.

If the guy had the bike long enough without knowing it had a pump, the tank is likely empty and you will need to fill it, bleed the line thoroughly, and verify pump flow. Then, and only then, connect the pump and run the bike on a small amount of premixed fuel until you are sure the pump is supplying oil.

Re: Suzuki fa50 oil pump/fuel line

To check for fuel flow you will have to softly suck on the end of the vacuum line that connects to the petcock. Otherwise nothing flows.

To check the oil pump undo the two screws that hold the pump to the tranny. Disconnect the line going to the intake. Spin the pump with a drill and see if the line drips oil. It won't be much but you should see it drip.

Re: Suzuki fa50 oil pump/fuel line

The petcock has a prime setting.

Re: Suzuki fa50 oil pump/fuel line

Sounds like a flooding issue. After you get it running, are you turning the petcock back to the run position instead of the prime? You shouldn't have to prime it again for a few days, at least my bikes never needed it.

I hate that priming petcock, with the feed behind it that goes into the body. Like every moped, when it works, it works well, but those parts tend to fill up with fuel gunk over the years.

I have a 1/3 FA50 body, 1/3 Honda Urban Express front and 1/3 parts that I run all the time but I decided to just make the petcock a straight line, run a mini rear tank and get rid of the fuel injection. But truthfully I like the oil injection on the FA50's.

Good Luck.

Re: Suzuki fa50 oil pump/fuel line

Thank you guys I'll check that oil pump today. This morning I started it up and it ran super well, got up to close to 30 and was driving for maybe 3-4 miles, then it started bogging a little bit again so I put it away. I was asking how to check if it was working because the guy I bought if from seemed to not know it even existed, so maybe he was just running premixed because he didn't know, burnim going to check and see if that's the problem too

Re: Suzuki fa50 oil pump/fuel line

Bogging down after 3 miles? Might be as simple as your carb float has a hole in it and can't open the needle all the way. Those brass floats have lots of tiny holes that develop. Take it out of the carb and shake it to listen for gas. If it has any liquid in it, you know that's your problem. To get the liquid out, find the tiny hole, then run compressed air on the side of the hole. This will create a nice venturi effect and suck out the gas. I then solder the hole if it's not to bad. I've also marine weld JB bonded tiny holes, or used gasoline resistant gasket maker if the hole was kind of high on the bowl. You can buy a new one also, but I thought they were kind of spendy. Good luck. Let us know if you fix the problem.

Re: Suzuki fa50 oil pump/fuel line

Yeah it's weird! I unscrewed the two tiny screws on the pump and a bunch of oil leaked out so I assume the pump is working like it should? I got new fuel line to make sure there's no holes in the vacuum tube or fuel line because it seems like maybe it's not getting enough fuel? I checked the float and it seems pretty solid no rust or when I shake it no liquid noise. I think it's running double oil but I'm still afraid to change it into regular non mixed gas because I'm not 100% sure. When full throttle it eventually will just cut off and die. I can't find much on this moped which is a bit frusterating.

Also does the battery effect running and starting? Or is it just for the lights and such.

Re: Suzuki fa50 oil pump/fuel line

Gregg Smith Wrote:


> I unscrewed the two tiny screws o

> n the pump and a bunch of oil leaked out so I assu

> me the pump is working like it should?

Just. Fucking. Wow.

Re: Suzuki fa50 oil pump/fuel line

Axldeziak . Wrote:


> Gregg Smith Wrote:

> --------------------------------------------------

> -----

> > I unscrewed the two tiny screws o

> > n the pump and a bunch of oil leaked out so I as

> su

> > me the pump is working like it should?



> Just. Fucking. Wow.

Sick! Like I said I've never had one of these before and have very little mechanical experience but I'm learning it now, I appreciate the feedback.

Re: Suzuki fa50 oil pump/fuel line

OH ! Holy shot dude sorry for the sarcasm I did the wrong two screws because I'm a moron, never the less did it right his time and it seems to be pumping correctly so there's a win and a laugh we can all share

Re: Suzuki fa50 oil pump/fuel line

Anyone still monitoring this thread? Bought a Suzuki FS50 for my wife's Christmas gift. Never used oil injection before and if it ain't broke don't fix it. May have to bite the bullet and follow the recommendations to bleed, just concerned with my zero experience with bleeding (aside from knuckles and brakes) I may make it worse. Previous owner responded to my text asking if he was using the oil injection. Based upon the condition of the oil tank it "appears" to be freshly used, and he confirmed he was using it, just make sure to let it warm up. I asked was he also using premix given the exhaust was quite smokey and he never replied.

Getting it set for winter I siphoned out his remaining fuel and put in 95 octane ethanol free 4 cycle gas. Topped off the oil tank with quicksilver 2 stroke oil synthetic blend. Says suitable for oil injection...Bought it at auto zone.

Around mid 40s today so took some work warming it up. The exhaust soon changed from blue to more of a gray. I was a little concerned but decided to take it for a quick spin to cycle through the fresh gas with stabil in it.

Seemed to be running fine but it didn't smell quite right and I started to worry I was burning up the engine. Probably rode it about 2 miles. I checked the oil level which had been at the very top of the filler neck and it was down to the bottom of the filler neck.

Any thoughts? Supposedly a "low smoke formula"...the only thing I have to compare this to is my Puch which doesn't smoke much. Love that moped.

Great site....been on it quite a bit during my moped search. Thanks in advance

Re: Suzuki fa50 oil pump/fuel line

I run Lucas . It's been working just fine for the last 11 years . Smokes very little .

The only time the injector didn't work was when I'd pinched an oil line , so no oil .

That cost me a bit over a 2 mile walk . :(

FA50 in stock form is pretty much bullet proof .

Re: Suzuki fa50 oil pump/fuel line

You know, I saw that on the shelf too...well, there's always next time.

Do you think it's a combination of high octane fuel with low smoke oil that's giving it the gray color? One thought I had is that maybe I'm burning out old deposits in the engine and exhaust?

I always figure two strokes would burn blue in color. Heading into winter I put two stroke ethanol free gas in the Puch....50:1 already mixed (expensive as !:#&) and hardly any smoke. But also not getting a burning smell.

If the previous guy was running p remix alongside the oil injection there's probably quite a bit that could burn up with a leaner mixture.

Thanks for such a quick reply. Love the enthusiasm

Re: Suzuki fa50 oil pump/fuel line

I sold this bike a while ago, but really all you do is spin that little part with a drill and if it’s working you’ll see it pumping. Apparently they are real durable I never had a problem after I figured it out. The Honda NC50i had, on the other hand, the oil pump was not working and I had to bypass it with vacuum caps and just run premix.

Re: Suzuki fa50 oil pump/fuel line

You might remove the exhaust and clean it out .

Oven cleaner seems to work pretty good .

Fill the pipe and let the cleaner work for a while . Then rinse with the garden hose .

Repeat .

The smoke should 'clear' a bit after you run the bike for a while and it gets use to how you run it and what you're running in it .

I run regular 87 octane gas . (edited)

Re: Suzuki fa50 oil pump/fuel line

Thanks all. The smell doesn't really bother me, so long as it isn't the piston and cylinder burning up. I appreciate the input. I truly appreciate the Puch for its simplicity but i think my wife will enjoy the option of simply gassing up at a gas station with her FS50. I'll be spending the next few weeks making it look "pretty" (remove rust, repaint, new seat, muffler cover) so maybe she'll get excited for next spring. She's lukewarm about the moped idea but I think she'll come around.

Re: Suzuki fa50 oil pump/fuel line

Came across a post by someone 12 years ago with a Suzuki TS 125, who was having oil injector problems. Forgive my ignorance is this was written already (I'm sure it was) but would his procedure work on the FS50 for priming?

Direct quote:

pull the in line off the pump and let the oil run through the line to force all the air out of the line. When the air bubbles quit coming out and you have a solid stream of oil hook it back up. Take the out line off and kick the bike over until oil comes out of it (it ain't much so you have to watch it close) then hook it back up. Make sure the passage is clear where it goes into the carb.

End quote. My question - is there any chance of introducing air especially with a disconnected out line hose when kicking the bike over and then reconnecting with the bike obviously off? I'm still not 100% convinced my oil injection is working. I guess logically seeing the oil level go down and not seeing any oil leaking anywhere then it must be going into the engine, but like I said, I'm new.

Or I'm craving shop talk during a pandemic...

Re: Suzuki fa50 oil pump/fuel line

I'd leave the pump out line in place and disconnect that line where it enters the carb .

Then check flow .

That much less line to have possible air in .

Re: Suzuki fa50 oil pump/fuel line

What kind of oven cleaner? Most I've seen comes in aerosol. How long to let it "cook".


Re: Suzuki fa50 oil pump/fuel line

Just go the the dollar store and pick up the cheapest stuff you can find . I fill the pipe and go do something else . An hour isn't too long to let it sit , before a rinse . Then do it again . And , yes , aerosol works fine . ;) (edited)

Re: Suzuki fa50 oil pump/fuel line

Awesome - thank you for the quick reply. I had burned out the muffler earlier this fall, but now have rest of bike together and finally out for test ride yesterday. Wouldn't go over 22mph. Figure I'd start with the exhaust (have ordered manifold pipe gasket too).


Re: Suzuki fa50 oil pump/fuel line

Cleaning the exhaust is a very simple first step .

Cheap insurance to know that end of the equation is copacetic .

Just as a precaution , I usually run a 1/4" rod into the tail pipe all the way to the front of the muffler . If I don't have a rod or wood dowel , I use a piece of stiff wire .

Re: Suzuki fa50 oil pump/fuel line

Roger that. Will give it a reaming.


Re: Suzuki fa50 oil pump/fuel line

> Joe Rich Wrote:

> -------------------------------------------------------

> Roger that. Will give it a reaming.


> Joe

If you live in an area that has mud daubers , keep whatever you use to 'ream' around as there may well be occasion to use it again .

I've had those little critters totally mud the tail piece shut , as well as the lower baffle hole inside the muffler .

Had me scratching for a reason why the bike would not start . ;)

Re: Suzuki fa50 oil pump/fuel line

Decided I was over thinking it and on a nice day today I fired it up. The fuel peacock is stuck in the ON position so I couldn't use the prime option....just kicked it 7 or 8 times and it started.

Gave it a long warm up and then slowly started on a test ride. Gradually opened it up and it ran great.

Here's my mini restoration...sorry to the hard core enthusiasts, my wife's favorite color is orange so it's no longer the traditional red and white. Fire orange and a DIY magnet decor, new seat cover and muffler cover.

Fun little ped...much more responsive than my Puch. A stinkier (lol)

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