Jonway 150 Won't Start By readnwrite (Read 8,164 times)

[readnwrite]

Hi All, I'm brand new to the forums and I have a problem with my Jonway 150cc scooter.

The scooter is practically new (31 mi on the odometer) but spent the last 4 months sitting in the garage of the guy I got it from. When I picked it up from him, it started right up, ran for about 10 minutes, then stalled. Since then, I haven't been able to get it running for more then a couple minutes (let alone ride it!!)

I figured the problem might be with the gas after sitting for so long, so after trying some things, we finally siphoned out the old gas, added new gas (along with some lucas fuel additive to combat any sludge from the last tank) and still nothing doing. It seems like I can get it to start after leaving it for a while, but then it stalls again.

I am wondering if maybe there's just some congealed/junky gas still in the fuel lines that I'll just have to burn through, of if it might be something else. Also, I tried to feed gas straight into the carburetor as per the little paper that came with the bike (no manual of course), but this didn't help, and I may not have even used the right tube connection as the diagram was so bad.

I feel like my hands are tied b/c I have no "map" (manual) to help me navigate the engine components.

Any suggestions are appreciated!!!

[kz1000st]

Try installing a new spark plug. They crud up sometimes and short out internally. Besides it's an old two stroke tip and helps sometimes.

[bullet]

I would check vacuum and gas lines and put in a new sparkplug. You might need a carb. and air filter cleaning. 4 months on the same gas is very questionable. I would not trust it. Without vacuum to the petcock gas will not flow so change the lines. Just because they look good on the outside does not mean they are good on the inside. While you are at add a gas filter. With the low miles it may have never had a good PDI. Change the valve stems. The cheap ones can go. Make sure the battery is good.

[Bashan]

Jan 13, 2012 11:54:04 GMT -6 readnwrite said:

I feel like my hands are tied b/c I have no "map" (manual) to help me navigate the engine components.

Kz and Bullet have some good suggestions. As an English grad student you should appreciate this aspect of the forum. Look down the main page a bit and you'll see the Library. It is broken down into categories such as Air & Fuel, Engine, etc. You should be able to peruse through them and find guides for just about any system of the scooter. To get you started, here is a link to fuel and vac line identification, and here is a cutaway view of a GY6 engine. There's much, much, more in the Library. Rich

[sprocket]

Sounds like your jets are plugged. Fuel in 2-3 months sitting deposits sticky varnish which plugs these carbs solid...

Also run a fine wire through all the carb passages and both jets...

[Alleyoop]

Readnwrite,
Lets FIRST do this, Take some pictures of the Carb Area and hoses going and coming from the Gas tank to the carb etc..

It has been sitting in this guys garage for to long with fuel in the carb may have turn the fuel in the passages into VARNISH and clogs up passages as well as the Float Plunger to allow gas to come in and fill the bowl. If that is the case then you will have to TAKE THE CARB off and Clean it out.

BUT FIRST LETS CHECK SOME THINGS OUT:
A. Pull the FUEL LINE FROM THE CARB and get a container and put the hose in there to catch the gas.
NOW CRANK the engine
1. If fuel FLOWS out that is good- THEN WE HAVE TO CLEAN OUT THE CARB.

2. If fuel DRIBBLES out then-- THEN WE HAVE TO CHECK THE FUEL FILTER AND PETCOCK VALVE--GO TO "C"

C. FUEL FILTER :
If the Fuel Filter is BETWEEN the CARB and PETCOCK-TAKE THE FUEL FILTER OFF.
1. Crank the engine
....If Fuel FLOWS out --- CHANGE THE FUEL FILTER it was clogged.
....If Fuel Still Does not FLow .. Then the PETCOCK has to be checked if it is CLOGGED or BAD VACUUM.

D. PETCOCK:
1. Same thing with Filter off and just the Petcock left You can either crank the engine or SUCK ON THE VACUUM LINE attached to it to see if FUEL FLOWS out when you suck on the Vacuum line to open the Diaphgram in the Petcock to allow fuel flow.
IF NO FUEL FLOWS sucking on it REPLACE PETCOCK-- IF FUEL FLOWS OUT CARB is the PROBLEM and needs to be cleaned out.
Alleyoop

[tvnacman]

I suspect tight valves , and maybe pluged carb as sprocket said . I would change the fuel filter .
John

[sprocket]

I agree with John set your valve gaps... occasionally scooters come from the factory with NO gap...

[tvnacman]

those chinese carbs , I have not had too much luck with cleaning them . They never seem right I'm finding with all the time spent to fix them , it seems wastefull . I'm leaning to just replace them and get the better ones .

I would replace the fuel filter .

John

[jct842]

easier than checking valve gaps is if you just happened to have a cheap compression tester. removing sparkplug and screwing it in place, throttle open, you crank it till gauge doesnt get any higher 3-4 revolutions or so. if you get much less than 150 lbs then it is time to pull the valve cover and get greasy. a valve that has closed up the gap might have 90-120 lbs and scooter refuse to start, adjust and it will go back to 150. I have done that with mine a couple times when it baulked starting and each time the compression was low till I adjusted valve gaps......a compression gauge is certainly not necessary but it is really easy to diagnose a starting problem after you find spark and have fuel flow. john

[Kaveman]

Using a bit of seafoam with fresh gas will help abit aswell once your able to get the engine going.
will

[roketafan]

gotta luv that ethonal,more than a few months sitting and blam varnish...