It's always the carb...unless it's something else. XF200

david3921 · 04-23-2011, 03:56 AM

So, my XF200 was running crappy after getting it out of winter storage. Even though I treated the gas and ran it long enough to get it circulated well, I drained it and replaced with new. Ran a little better but wouldn't idle well, surging. I thought that I might have gotten something in the carb so I pulled the jet and made sure it was clear. Looked good. Buttoned everything back up but same problem. So, thinks I, vacuum leak. I had two plugs on the carb from when I removed the air injection stuff so I replaced them.

Nope, still no love.

While the bike was running, I pushed on the plugs to make sure they were seated well. The idle changed when I pushed on the top plug. Mmmm...something is becoming clearer. I could vary the idle moving the carb up and down so I grabbed a can of WD40 (I didn't have a propane cylinder or starter fluid) and sprayed around the intake manifold. Yep, the idle changed.

Eureka! I have a manifold leak!

So, I took the carb and manifold off. Yep, the top of the manifold had a split in it. I didn't get a picture of it so I borrowed a picture from Andrew's jet change post to show the location (I hope you don't mind, Andrew).

I used JB weld to fill it in and clamped it until dry. I will install it tomorrow but am confident that my idle problems will disappear. I have not heard of this happening on Qlink/Qingqi bikes but have read about other makes.

Maybe I was too agressive when I changed the jets and did it then. Or it could be another cost cutting measure we have to deal with. I did notice that the screws holding the manifold on did not have any thread lock on them. They do have lock washers, however. They were not on super tight, either. I am replacing them with bolts, however, so that I can torque them correctly. I also put a thin bead of sealer in the manifold O-ring groove to raise the seat up a bit.

So, I guess that I would recommend that your manifold screws be checked and tighted (along with all the rest) and maybe even replaced with bolts.

04-23-2011, 03:56 AM	#1
david3921 Join Date: Feb 2009 Location: Michigan Posts: 1,031	It's always the carb...unless it's something else. XF200 So, my XF200 was running crappy after getting it out of winter storage. Even though I treated the gas and ran it long enough to get it circulated well, I drained it and replaced with new. Ran a little better but wouldn't idle well, surging. I thought that I might have gotten something in the carb so I pulled the jet and made sure it was clear. Looked good. Buttoned everything back up but same problem. So, thinks I, vacuum leak. I had two plugs on the carb from when I removed the air injection stuff so I replaced them. Nope, still no love. While the bike was running, I pushed on the plugs to make sure they were seated well. The idle changed when I pushed on the top plug. Mmmm...something is becoming clearer. I could vary the idle moving the carb up and down so I grabbed a can of WD40 (I didn't have a propane cylinder or starter fluid) and sprayed around the intake manifold. Yep, the idle changed. Eureka! I have a manifold leak! So, I took the carb and manifold off. Yep, the top of the manifold had a split in it. I didn't get a picture of it so I borrowed a picture from Andrew's jet change post to show the location (I hope you don't mind, Andrew). I used JB weld to fill it in and clamped it until dry. I will install it tomorrow but am confident that my idle problems will disappear. I have not heard of this happening on Qlink/Qingqi bikes but have read about other makes. Maybe I was too agressive when I changed the jets and did it then. Or it could be another cost cutting measure we have to deal with. I did notice that the screws holding the manifold on did not have any thread lock on them. They do have lock washers, however. They were not on super tight, either. I am replacing them with bolts, however, so that I can torque them correctly. I also put a thin bead of sealer in the manifold O-ring groove to raise the seat up a bit. So, I guess that I would recommend that your manifold screws be checked and tighted (along with all the rest) and maybe even replaced with bolts.
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