I have a Shindaiwa T-20 weed wacker. It'll run fine for a while then just stop running. It does this over and over, and sometimes it'll run for 20 minutes fine, sometimes every 60 secs it'll die.

Everything points toward a gas supply problem. I've replaced the carb, spark plug, checked the spark (very strong looking), when it's hard starting I can usually start it with ether spray. Sometimes when it acts like it's going to die, if I shake it back and forth it will keep going, there are times when I can keep it running by turning it upside down.

Inside the tank is a flexible rubber fuel tube with a weighted filter at the end. This tube had a hole in it (sucking air?) so I've temporarily replaced it with a solid copper line. Yes, I guess that defeats the purpose of the flexible rubber tube(so wacker will run at all angles), but I'd think if the weighted fuel filter was immersed in the gas/oil mix then it should run, regardless of the flexibility of the fuel line. But it still has the dieing problem even when the filter is immersed.

I'm trying to figure out how this fuel supply/feed works...are there vents that I can check that might cause this problem. The parts breakdown shows a small check valve just above the weighted fuel filter but I've never seen one there. Could it's absence cause this off and on problem.

Can someone show me a way to troubleshoot this. I've been able to run a gas line directly from carb to a can of fuel mix, and it seem to run fine that way, but I can't really do that for more than a few minutes so it may not be a definitive test. I've had this problem for years, through many carb rebuilds, the recent replacement, replacing electronics...I think everything points towards the gas tank and fuel supply so I'd appreciate some basic ideas on how that works and any thoughts about this problem.

Yes, I'm long winded about this, but then I've been dealing with it for so long!

John

ps: compression is 50 psi, is this normal or low?
pps: I've also tried running the wacker with the gas cap loose, for venting purposes, but this doesn't make any difference.

 

Here's a thread about the same thing. I think 30yrtech's reply is going to apply to you moreso than my reply on that thread.

 

Hi Mr. Cheese...I don't see a link in your message, and I'd like to follow it. Could you post it again?

John

 

Sorry, I don't know what happened. I'll try again here:
http://forum.doityourself.com/showth...ight=shindaiwa

 

I did not see a solution posted for this probelm. I have the same problem. Thank you very much

 

You may want to start a new thread, but if your fuel lines are hard and brittle replace them with new flexable fuel line. Also most weed wackers compression is normal at 120 lbs or better. If lower than 90 LBS you will have problems starting it.