iDRY Vacuum Kilns

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got the 250 together and runs great,but

Started by southdakotasolo, July 28, 2017, 11:43:40 PM

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southdakotasolo

got it together yesterday and cked the vac to make sure the new seals sealed and started it up. set carb to the book settings and it tried to start but acted like it was real rich, so I turned the L needle to about 3/4 and it still would not start. so ckd plug and it was flooded. cleaned plug and pulled the rope 20 times and reinstalled plug. turned needle in a 1/4 more and it ran. played with the L needle and it would run with it closed. backed it out about 1/2 turn and it runs great. high speed is right on. it will go to idle after cutting but will quit every once in a while. can not figure why the idle screw seems to do nothing to the idle. it opens the throttle as it is supposed to, to change the idle speed but the speed never changes. strange.  i'am thinking a damaged L speed seat. any suggestions welcome. I am thinking find a walbro replacement carb. have never had a problem with the zama carbs before. thks again         

joe_indi

3 possibilities
Metering lever is high
Metering needle has worn out
The pump diaphragm might have a leak.
With the last, at every impulse inwards fuel would go directly into the crankcase causing engine to run very rich. But beyond an rpm it would lean out because the leak would prevent proper fuel delivery

southdakotasolo

will ck items suggested. put in new kit with rebuild but would not be the first time new parts could have failed. quality cking seems to be a thing of the past thks joe wlw

Air Lad

Quote from: joe_indi on July 29, 2017, 12:15:31 AM
3 possibilities
Metering lever is high
Metering needle has worn out
The pump diaphragm might have a leak.
With the last, at every impulse inwards fuel would go directly into the crankcase causing engine to run very rich. But beyond an rpm it would lean out because the leak would prevent proper fuel delivery
Not sure if you're carb is Zama or Walbro but Zama website gives a troubleshooting chart. It says this issue could be a leaking welch plug,(mine was on Husky240) or Idle and main mixture screw seats damaged. Either way the carb is certainly a likely culprit .Frustrating times but a chance to learn stuff. Good luck with it.

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