GY6 150cc hard start

[bookel]

Plenty of juice in battery. Cranks fast. When cold the engine will not fire unless I use starter spray through the carb. Then I have to keep using the accelerator to keep it running until its warmed up. Once warm it starts without using the accelerator or starting spray no problem.

Troubleshooting so far:

New spark plug and has nice white and blue spark.
Adjusted valves (and they needed it).
Pulled enricher and connected to battery. Plunger moves out as it should.
New high performance CDI put in. (Issue was present with stock CDI).
High performance coil already installed.
Cleaned carb.
Fuel filter is good (fuel flows freely through entire fuel line).

I'll probably check the timing tomorrow but I don't think that is it.

 

[OzFab]

Are you starting it with the choke?

My 8hp B&S riding mower will not start with the choke on but, that's the exception to the rule, just about every engine needs the choke on to cold start...

 

[bookel]

Supposedly it has electric choke. Whether it is working or not is still in question. I hadn't thought of that. I hope to get that checked today. If its not working I'll probably hook up a manual control to the choke plate. I prefer to have control rather than have it done automatically.

Good thought. Thanks. Keep the ideas coming.

 

[2SlickNick]

The gy6 does not have a choke function. It has the fuel enrichment valve. Which You stated it works as it should...
How is the manifold? Any cracks?
Could you possibly get a video of it running?
Are there any up grades to the air fuel system? Is the pilot jet stock? What about mixture screw setting?

 

[kevin.st56]

iv always called it the auto choke, as that's what everyone on the buggynews forum call it too..

those valves do fail quite often on the GY6s.
there is a way to setup a manual control to replace the automatic one

http://buggynews.com/i-need-help-with-the-gy6-manual-choke-bolt-mod-t42796.html

My manco is always a pain to start when its been sitting for a long time.
I had started mine over the weekend (wasn't ran for several months), and I always had to press the gas pedal just a little bit for it to start and idle for the first few minutes. After that, itll idle on its own just fine

 

[colestreasures]

Im wondering how well the starter is turning and what kind of shape the belt is in.

 

[2SlickNick]

I did the manual conversion on my Carbide 150cc.
It did well during the warmer months... But during winter I changed it back and it is just one less thing to worry about.

 

[bookel]

Well, I tried an old trick my grandad showed me once. Last night ebfore going to bed I got it running, with starter spray, and disconnected the fuel line while clamping off the end at the gas tank. I then started pourinf sea foam carb and injector leaner into the fuel line going to the carb. Doesn't have to be sea foam. I did this while the engine was running. I kept pouring it in a little at a time. It comes up to the top of the fuel line and you stop. Then you see the fuel go back down. I kept doing this until it started running rough, pretty much pure sea foam in the carb at that point. I turned the engine off and let it sit til this afternoon. I just went outside and it cranked first try no sprays and no accelerator pumping. I drove it around for about 5 minutes and its moving like a scalded dog.

My grandad used to be a Mach truck specialist. He told me this was a way he learned to clean the insides of carbs without taking it off or apart. It works almost every time if your carb is gummed up. I guess mine was.

 

[OzFab]

So, it starts & runs as it should now?

 

[kevin.st56]

Well, I tried an old trick my grandad showed me once. Last night ebfore going to bed I got it running, with starter spray, and disconnected the fuel line while clamping off the end at the gas tank. I then started pourinf sea foam carb and injector leaner into the fuel line going to the carb. Doesn't have to be sea foam. I did this while the engine was running. I kept pouring it in a little at a time. It comes up to the top of the fuel line and you stop. Then you see the fuel go back down. I kept doing this until it started running rough, pretty much pure sea foam in the carb at that point. I turned the engine off and let it sit til this afternoon. I just went outside and it cranked first try no sprays and no accelerator pumping. I drove it around for about 5 minutes and its moving like a scalded dog.

My grandad used to be a Mach truck specialist. He told me this was a way he learned to clean the insides of carbs without taking it off or apart. It works almost every time if your carb is gummed up. I guess mine was.

I may have to look into this for mine.
I prefer using marvel mystery oil tho, but have used seafoam before

 

[bookel]

Yes mine is running as it should now. Starts after one or two tries.