257 cc Linhai Won't Start or Fire After Fuel Pump Replaced
 

Hi there.

I have a 257 cc Linhai on a JCL 260. I replaced my vacuum fuel pump with an electric one since it was running short on fuel at high speeds with low vacuum. It appeared to run good. I took it for a test ride for 80 miles during which it ran great until it died. It won't start or fire after this.

I am trying to get it going again. I can hear my electric fuel pump running. Fuel drains out the drain for the carb bowl when I open it. When I take the spark plug wire off then hook it to a different spark plug that is grounded I get spark when I turn the engine over.

I'd appreciate any help I can get to make it fire and start. Any ideas where to go from here?

Thanks for your help.

diffrent plug????.... why not take the one out of
the motor and see if it sparks... after all it's the one
you are using to try and start the motor...

what is the out put PSI of this new electric fuel pump..
It could be over riding the float valve if the PSI is to high..



..

What's the voltage reading? Those igniter relies on stable DC source...
---
The trick for those DC mystrey black box http://translate.baiducontent.com/tr...en=&monLang=zh

Hi Bob, what are you riding? I'm unfamiliar with a JCL 260. Is it a scooter?

Thanks for everyone's help. That is what I need.


The fuel pump is a Facet 40105 the details of which can be seen here:


http://www.facet-purolator.com/cube-fuel-pump-kits.php


and here:


https://www.aircraftspruce.com/catal...facetpumps.php


I will pull the plug that is in the cylinder as a next step to see if I get spark


The electric pump has a pressure of 3.0-4.5 psi and a flow rate of 30 GPH.


The battery is fully charged.. Ignitier??? I am not sure I understand. It turned over fired started and ran before this change.


The JCL MP250A is a scooter with a Linhai 257 cc motor. You can see more details here:


http://www.jclusa.com/MP250A.htm

Anyone have any ideas how I can get this going?

I'm wondering if the electric fuel pump is enough to unseat the float valve.


One thing I dislike about modern scooters is the vacuum-operated fuel pump. It seems to me that the design is due to the bodywork that precludes a typical fuel petcock. The bandaid vacuum pump stops pumping when the engine stops running. All great in theory, but a nuisance when they fail or run out of fuel at low vacuum.


Do you have a way to ditch the fuel pump and add a petcock? That should provide a steady supply of fuel at gravity pressure, assuming your tank is higher than the carb.

The tank is lower than the carb so gravity won't work here.

Could you go to a better quality vacuum pump, like a Honda product? I replaced enough vacuum pumps on a friend's China scooter to know I don't trust them. Fuel would often leak through the China pump and fill the crankcase with gasoline.

The problem isn't that the vacuum fuel pump failed. It is that at high rpm vacuum is too low to drive high volumes of fuel with a vacuum fuel pump. That is why I went to the electric fuel pump.

I'm with you on that. I'm wondering if a Honda vacuum pump might have a different spring rate than a China vacuum pump that would allow high RPM fuel flow. It's only a theory.


For now, have you considered putting the stock pump back in, to confirm that nothing else is causing the symptom?

I agree with Weldandgrind. This may not have been a fuel pump issue. could be that you may need to up the main jet size or valve adjustment. Have you checked the valves for adjustment? They may be set to tight. Does it fire up after you changed the spark plug?

Right now I don't understand why it won't fire. I have fuel in the bowl of the carb when I open the drain hose.


It seems like it is something simple I am missing. It ran real good for 80 miles then died and now wouldn't fire.


Both WeldanGrind and Pete asked about the fuel pump pressure could overpower the float. At what PSI would something like this happen?


I may have to go back to the vacuum fuel pump but need to eliminate everything else first.


What would cause it not to fire when there is fuel in the carb bowl?

JerryHawk250 I missed your post while I was writing my last one.


The valves were adjusted twice and it made no difference to the fuel flow at high rpms issue. The spark plug is a new one, the same one that it ran 80 miles with and ran real good.

May have already been asked/answered but will it fire if you squirt a little gas into the cylinder or spray a little starter fluid in the intake?



/