2006 Linhai 300
Was hard to start and when I finally got it started it would start to run poorly and then backfire. I may take a look at the petcock (location?) but really wanted to try a new carb before I gave up on this thing. Pretty sure I've let bad gas sit in the past before I knew better.


Unfortunately the carb is under the gas tank which is under a plastic body frame with about 100 screws. Any shortcuts??? And no, unfortunately carb cleaner didn't work.


Thanks in advance!

 

The location of the petcock should be near the underside of the gas tank. Typically this is the fuel shut-off valve.
As far as a short cut to getting at the carb, I would just remove the plastics as you gain easier access. I would remove the carb completely from the engine and take it apart. If gas has sat in the carb bowl for an extended period there is a good chance that the carb has varnish in it. Carb cleaner alone usually does not do the job of cleaning this. I personally use torch tip cleaners and small bits of wire to clean all the small passages and jets then spray it down with carb cleaner and blow out with compressed air.

 

Thanks a lot. I did end up having to take a LOT of stuff off and was finally able to remove the carb. It appeared to have a lot of carb cleaner/starter fluid/gas in it. It looked like it had some varnish in the bottom when I took it apart but nothing else was obvious. I attempted to clean it and drained all the gas from the gas tank for good measure. Since my understanding of the carb is so limited I think I'll order a new one so I can rule it out if I end up passing this on to someone more skilled than me. Hoping the new carb works! and fits!! Thanks for your advice.

 

I hope all goes well for you! Keep us posted on the outcome!

 

So I finally got the new carb in. Didn't start initially but I went back after a few minutes and it started! And ran well! Was even able to drive it around the yard!Went back Day 2 and was able to start it again. Later Day 2 wanted to impress the wife and it wouldn't start! Didn't appear to have spark so I attempted to check a few things but when I put it up later it DID have spark. Was unable to get it started because the battery had run down from my earlier attempts. So maybe I fixed the fuel problem with a new carb because it seemed to be running well but WHY am I having what seems to be an intermittent starting problem? Cranks but won't start. I'll try it again but any ideas on this are appreciated. Frustrating because it DID run perfectly for awhile and now the spark is showing back up so, at least for awhile, I had fuel and spark. Kill switch seemed to be working but can it be intermittent?

 

You can do a test on the kill switch to see if it is the issue you are having. There should be a black/white wire running from your CDI box up to your kill switch. You cut this wire and then try cranking the machine over to check for spark. If you see that you now have spark you know that the kill switch is at fault and it would either need to be replaced.

There are some really informative videos on youtube. Search for Harvey Spooner on YouTube, he has several videos about the electrical on these Chinese quads.

Hope this helps!

MNSTORM

 

Thanks. I'll look for those videos. I tested for spark and do have it consistently. I think I have fuel because I can smell it but not sure. Is there an easy way to make sure fuel is getting all the way through? Still frustrated because it started and ran and now it won't start!

 

Try disconnecting the fuel line from the carb to see if you have a steady flow of fuel coming out. If gas flows out reattach the fuel line to the carb.

• If no fuel, check to see if petcock is off or if there is something in your fuel line/plugged fuel filter.

Next, there should be a small drain screw on the bottom of the carb bowl. Unscrew this and see if gas starts to flow out of the over-flow tube.

• If no fuel flow here, you more then likely have a float needle sticking closed in the seat. (you will need to disassemble the carb to clean this) Ive used a q-tip inserted into a cordless drill and metal polish to polish the seat area before. I had a sticking float needle on a new carb! This fixed my sticking needle issue i was having. After polishing clean with carb cleaner and compressed air. Make sure carb boots are tight as well.

You can also crank the engine for a bit then remove the spark plug and see if it is wet with gas then you know you are getting fuel.